17-hydroxypregnenolone Delta-5 steroid metabolite derived from the hydroxylation of pregnenolone, involved in the glucocorticoid and androgen synthesis pathway.

Also: 17-OH-pregnenolone · 17-hydroxypregnenolone

17-hydroxyprogesterone Crucial intermediate steroid in the synthesis of cortisol whose elevated blood levels are used as a neonatal screening marker for 21-hydroxylase deficiency.

Also: 17-OHP · 17-hydroxyprogesterone

25-hydroxyvitamin D-1alpha-hydroxylase Renal mitochondrial enzyme strictly regulated by parathyroid hormone that catalyzes the synthesis of the biologically active form of vitamin D.

Also: CYP27B1 · 1-alpha-hydroxylase · 25-hydroxyvitamin D 1-alpha-hydroxylase

3-beta-hydroxysteroid dehydrogenase Two-compartmental microsomal enzyme that catalyzes the conversion of delta-5-steroids into active delta-4-steroids during adrenal and gonadal hormonal synthesis.

Also: 3-beta-HSD · 3-beta-hydroxysteroid dehydrogenase

Abetalipoproteinemia Autosomal recessive disorder characterized by the complete absence of apolipoprotein B, preventing the formation and export of chylomicrons and very low density lipoproteins.

Also: Bassen-Kornzweig syndrome · abetalipoproteinemia

Autocrine action Chemical signaling modality where a cell secretes a messenger that binds to receptors located on its own cell surface, modifying its own activity.

Also: autocrine signaling · cellular self-control · autocrine signaling

Endocrine action Classic signaling mechanism where hormones are released directly into the bloodstream to travel to distant sites and interact with specific receptors.

Also: systemic signaling · internal secretion · endocrine signaling

Paracrine action Form of local endocrine communication where a chemical substance secreted by a cell diffuses through the interstitial space to act on adjacent target cells.

Also: paracrine signaling · neighborhood control · paracrine signaling

Juxtacrine action Type of cellular communication that requires direct physical contact between the membrane proteins of the sending cell and the receptors of the neighboring target cell.

Also: contact signaling · juxtacrine communication · juxtacrine signaling

Activin Dimeric protein complex belonging to the superfamily of transforming growth factors beta that actively promotes pituitary secretion of follicle-stimulating hormone.

Also: FSH activating factor · activity

Adenylate cyclase Effector membrane enzyme that catalyzes the conversion of adenosine triphosphate to cyclic adenosine monophosphate in response to the activation of stimulatory G proteins.

Also: adenyl cyclase · AC · adenylate cyclase

Toxic adenoma Solitary benign nodule in the thyroid gland that presents autonomic hyperfunction, overproducing thyroid hormones independently of the control of circulating thyrotropin.

Also: hot nodule · hyperfunctioning adenoma · toxic adenoma

Adipocin Heterogeneous group of regulatory peptides and cytokines synthesized and actively secreted by adipose tissue that influence systemic metabolism, inflammation and satiety.

Also: adipocytocin · adipocyte hormone · adipokine

Adipocyte Highly specialized connective tissue cell with the capacity to store large amounts of neutral lipids in its cytoplasm and with key endocrine metabolic functions.

Also: fat cell · mature adipocyte · adipocyte

Adipogenesis Biological process of cellular differentiation by which mesenchymal stem cells are transformed into functional mature adipocytes.

Also: adipocyte differentiation · adipogenesis

Adiponectin Protein secreted by adipocytes that improves peripheral sensitivity to glucose and exerts important anti-inflammatory and antiatherogenic effects.

Also: plasma adiponectin · adiponectin

Adrenarche Maturative period of early pubertal development characterized by the physiological increase in the secretion of adrenal androgens that precedes the activation of gonadotropins.

Also: adrenarche

Adrenoleukodystrophy X-linked neuroendocrine demyelinating disease due to mutations in the ABCD1 gene that prevent the transport and beta-oxidation of very long chain fatty acids in peroxisomes.

Also: ALD · Schilder-Addison disease · adrenoleukodystrophy

Adrenopause Physiological and progressive decline in the synthesis and secretion of adrenal androgens such as dehydroepiandrosterone that occurs naturally from the third decade of life.

Also: adrenopause

Alkaptonuria Rare autosomal recessive metabolic disorder caused by a deficiency of the enzyme homogentisate 1,2-dioxygenase that leads to the deposition of dark pigment in cartilage and early degenerative arthritis.

Also: homogentisate oxidase deficiency · hereditary alkaptonuria · alkaptonuria

Amylin Small peptide hormone co-secreted with insulin by pancreatic beta cells that regulates glucose homeostasis by delaying gastric emptying and suppressing postprandial glucagon secretion.

Also: islet amyloid polypeptide · IAPP · amylin

Endocrine amyloidosis Localized deposition of amyloid fibrils composed of abnormally folded hormones or peptides in the stroma of endocrine glands, such as in pancreatic islets in type 2 diabetes.

Also: endocrine amyloid · endocrine amyloidosis

Anastrozole Non-steroidal pharmacological agent, potent aromatase inhibitor, useful for drastically suppressing estrogen levels in postmenopausal women.

Also: anastrozole

Andropause Progressive, gradual, age-related decline in total and free serum testosterone levels in men, accompanied by corresponding clinical symptoms.

Also: late-onset hypogonadism · male climacteric · andropause

Androstenedione Nineteen-carbon steroid produced in the adrenal glands and gonads that serves as a direct and immediate precursor for the synthesis of testosterone and estrone.

Also: androstenedione

Angiotensin 1-7 Biologically active heptapeptide with vasodilatory, antiproliferative and antifibrotic properties that exerts a counterregulatory function against angiotensin II through the Mas receptor.

Also: angiotension 1-7

Angiotensin I Inactive decapeptide formed by the cleavage of angiotensinogen by renin that serves as a direct substrate for the angiotensin-converting enzyme.

Also: angiotensin 1-10 · angiotension I

Angiotensin II Extremely potent vasoactive octapeptide that induces systemic vasoconstriction, stimulates aldosterone secretion in the adrenal cortex and promotes sodium reabsorption.

Also: angiotensin 1-8 · angiotension II

Progesterone receptor antagonist Drugs or chemical compounds that competitively block the progesterone receptor, preventing its decidualizing and pregnancy-maintaining actions.

Also: antiprogestogen · progesterone receptor antagonist

Anti-thyroid peroxidase antibodies Autoantibodies directed against the thyroid peroxidase enzyme, highly sensitive and specific for the clinical diagnosis of Hashimoto's thyroiditis.

Also: anti-TPO · peroxidase antibodies · thyroid peroxidase antibodies

Anti-thyroglobulin antibodies Specific autoantibodies directed against thyroglobulin that serve clinically as biomarkers of thyroid autoimmunity and monitoring of differentiated thyroid neoplasms.

Also: anti-Tg · thyroglobulin antibodies

Apolipoprotein A-I Major structural and functional protein component of high-density lipoproteins that also acts as an activating cofactor of the LCAT enzyme.

Also: ApoA-I · apolipoprotein A-I

Apolipoprotein B-100 Major structural protein present in VLDL, IDL, and LDL lipoproteins that serves as a crucial ligand for LDL receptor-mediated cellular uptake.

Also: ApoB-100 · apolipoprotein B-100

Apolipoprotein B-48 Truncated isoform of apolipoprotein B that is synthesized exclusively in the small intestine and acts as an obligatory structural marker of chylomicrons.

Also: ApoB-48 · apolipoprotein B-48

Apolipoprotein C-II Lipoprotein surface protein that acts as an essential cofactor to activate the lipoprotein lipase enzyme and allow the hydrolysis of triglycerides.

Also: ApoC-II · apolipoprotein C-II

Apolipoprotein C-III Lipoprotein-associated plasma protein that strongly inhibits the activity of lipoprotein lipase and delays hepatic uptake of lipid remnants.

Also: ApoC-III · apolipoprotein C-III

Apolipoprotein E Glycoprotein present in multiple classes of lipoproteins that mediates rapid hepatic clearance by interacting with high affinity with the LDL receptor and related receptors.

Also: ApoE · apolipoprotein E

Pituitary apoplexy Acute endocrine emergency caused by hemorrhagic infarction of a pre-existing pituitary adenoma that clinically presents with intense headache, visual alterations and acute hypopituitarism.

Also: acute pituitary infarction · pituitary apoplexy

Athyreosis Extreme congenital defect characterized by the complete and total absence of functional thyroid tissue due to a total failure in the embryonic development of the gland.

Also: thyroid agenesis · athyreosis

Leber optic atrophy Subacute degeneration of retinal ganglion cells and their axons of mitochondrial inheritance that causes painless bilateral central visual loss in young men.

Also: LHON · Leber's hereditary optic neuropathy

Beta-oxidation Mitochondrial catabolic sequence by which two-carbon fragments of fatty acyl-CoA chains are successively cleaved to produce acetyl-CoA and reduced cofactors.

Also: oxidation of fatty acids · beta-oxidation

Multinodular goiter Diffuse and heterogeneous enlargement of the thyroid gland characterized by the presence of multiple autonomous or non-autonomous hyperplastic nodules in its parenchyma.

Also: nodular goiter · multinodular goiter

electron transport chain Complex of protein transporters embedded in the inner mitochondrial membrane that transfer electrons from reduced cofactors to oxygen, generating a proton gradient.

Also: respiratory chain · electron transport chain

Calcidiol Major circulating form and systemic reservoir of vitamin D, hydroxylated at position 25 in the liver, used clinically to monitor the nutritional status of this vitamin.

Also: 25-hydroxyvitamin D · 25(OH)D · calcifediol

Calciphylaxis Severe syndrome characterized by diffuse calcification of the media of small caliber arteries in the dermis and subcutaneous cellular tissue, leading to painful skin ischemia and necrosis.

Also: calcifying uremic arteriolopathy · calciphylaxis · cutaneous calciphylaxis

Calcitonin Peptide hormone of thirty-two amino acids secreted by parafollicular C cells of the thyroid that reduces calcium levels by directly inhibiting bone resorption by osteoclasts.

Also: thyroid calcitonin · thyrocalcitonin

Calcitriol Active steroid hormone vitamin D, hydroxylated in the 1-alpha position in the kidney, which actively stimulates the intestinal absorption of calcium and phosphate.

Also: 1,25-dihydroxyvitamin D · 1.25(OH)2D · calcitriol · 1,25-dihydroxyvitamin D3 · active hormone D3

Anaplastic thyroid carcinoma Extremely aggressive and rapidly growing epithelial thyroid tumor characterized by undifferentiated cells with lethal clinical behavior with massive local infiltration.

Also: undifferentiated thyroid carcinoma · anaplastic thyroid carcinoma

Follicular thyroid carcinoma Well-differentiated malignant thyroid epithelial neoplasm characterized histologically by complete capsular or vascular invasion of follicular structures.

Also: CFT · follicular thyroid carcinoma

Medullary thyroid carcinoma Malignant neoplasm of the thyroid originating from calcitokinin-secreting parafollicular C cells, which is frequently associated with hereditary MEN 2 syndromes.

Also: CMT · medullary thyroid carcinoma

Papillary thyroid carcinoma The most common differentiated malignant neoplasm of the thyroid, histologically characterized by optically empty papillae and cell nuclei known as orphan Annie's eyes.

Also: TLC · papillary thyroid carcinoma

Parafollicular C cell Cell of neuroectodermal origin dispersed in the thyroid parenchyma whose main function is the production, storage and secretion of calcitonin.

Also: parafollicular cell · C cell

Cetrorelix Selective peptide antagonist of the GnRH receptor used clinically to prevent premature surges of luteinizing hormone during cycles of controlled ovarian stimulation.

Also: cetrorelix

Krebs cycle Series of mitochondrial enzymatic reactions that oxidize acetyl-CoA to carbon dioxide and water, generating reduced cofactors crucial for oxidative phosphorylation.

Also: citric acid cycle · tricarboxylic acid cycle · citric acid cycle

urea cycle Mitochondrial and cytosolic hepatic metabolic pathway that converts the highly toxic ammonia derived from the catabolism of amino acids into water-soluble urea that is less harmful for renal excretion.

Also: ornithine cycle · urea cycle

Cystinosis Autosomal recessive lysosomal disease characterized by the intracellular accumulation and deposition of cystine crystals due to mutations in the lysosomal cystine transporter cystinosine.

Also: hereditary cystinosis · cystinosis

Cystinuria Hereditary defect in the transport of amino acids in the renal proximal tubule that makes the reabsorption of cystine and dibasic amino acids impossible, promoting the recurrent formation of cystine stones.

Also: cystine kidney stones · cystinuria · cystine tubular defect

Hormonal clearance Rate or volume of plasma that is completely cleared of a hormone per unit of time through metabolic degradation processes, renal or biliary excretion.

Also: hormonal clearance · hormonal purification · hormone clearance

PPAR-gamma coactivator 1 alpha Transcriptional coactivator that exerts master control over mitochondrial biogenesis, hepatic gluconeogenesis and thermogenesis in brown adipose tissue.

Also: PGC-1alpha · PGC-1alpha

Cholecystokinin Gastrointestinal hormone released by the duodenum that stimulates the contraction of the gallbladder, the secretion of pancreatic enzymes and acts as a signal of satiety at a central level.

Also: CCK · cholecystokinin · cholecystokinin

Progressive familial intrahepatic cholestasis Genetic disorder due to defects in canalicular bile acid transporters that causes progressive liver damage that progresses to terminal cirrhosis in childhood.

Also: CIFP · Byler's disease · progressive familial intrahepatic cholestasis

Cholesterol desmolase Mitochondrial enzyme that catalyzes the initial rate-limiting step of steroidogenesis by converting cholesterol to pregnenolone by cleaving its lateral side chain.

Also: CYP11A1 · cholesterol side chain cleavage enzyme · cholesterol side-chain cleavage enzyme

Carney Complex Autosomal dominant multisystem tumor syndrome due to alteration of the PKA regulatory subunit, manifested by myxomas, cutaneous lentigines and adrenal and pituitary endocrine hyperactivity.

Also: Carney complex

Counterregulation Set of coordinated endocrine and metabolic responses that oppose the action of a dominant hormone in order to avoid extreme metabolic deviations.

Also: counterregulatory response · metabolic counter-registration · counterregulation

Klotho co-receptor Indispensable membrane protein that acts as an obligatory cofactor to allow selective intracellular binding and signaling of FGF23 in renal and parathyroid tissue.

Also: Klotho alpha · Klotho

Corticosteroma Hyperfunctioning benign adrenal adenoma that autonomously and excessively secretes active glucocorticoids, clinically inducing a picture of primary hypercortisolism.

Also: cortisol-producing adrenal adenoma · corticosteroma

Corticosterone Intermediate glucocorticoid in the adrenal biosynthetic pathway that acts as the main stress response glucocorticoid hormone in rodents and as a minor precursor in humans.

Also: corticosterone

Corticotropin Polypeptide hormone produced by the corticotropic cells of the anterior pituitary that stimulates the synthesis and secretion of glucocorticoids in the adrenal cortex.

Also: ACTH · adrenocorticotropic hormone · corticotropin

Cortisone Inactive circulating glucocorticoid that is interconverted to its active form through the enzymatic action of 11-beta-hydroxysteroid dehydrogenase type 1.

Also: inactive metabolite of cortisol · cortisone

Sodium-iodine cotransporter Secondary active transporter glycoprotein located on the basolateral membrane of thyrocytes that actively captures iodide against a cellular concentration gradient.

Also: NIS · sodium-iodide symporter

Craniopharyngioma Benign neoplasm of epithelial origin originating from remnants of Rathke's pouch that compresses the optic chiasm and the pituitary stalk, causing progressive endocrine dysfunction.

Also: supracellar epithelial tumor · craniopharyngioma

Adamantine craniopharyngioma The most common histological subtype of craniopharyngioma in childhood that histologically shows palisaded epithelial nests that simulate the stellate reticulum of the dental enamel organ.

Also: infantile craniopharyngioma · adamantinomatous craniopharyngioma

Cretinism Clinical syndrome characterized by profound stature and neurological delay secondary to severe untreated hypothyroidism of congenital or neonatal onset.

Also: infantile cretinism · cretinism

Adrenal crisis Serious and hypotensive medical emergency caused by a severe and acute deficiency of glucocorticoids, manifested by refractory cardiovascular collapse, vomiting, fever and electrolyte imbalance.

Also: acute adrenal crisis · adrenal shock · adrenal crisis

11-beta-hydroxysteroid dehydrogenase type 2 deficiency Molecular defect that prevents the protective conversion of active cortisol into inactive cortisone in the renal collecting duct, making it easier for cortisol to overactivate mineralocorticoid receptors.

Also: 11-beta-HSD2 deficiency · 11-beta-HSD2 deficiency

11-beta-hydroxylase deficiency Variant of congenital adrenal hyperplasia produced by mutations in the CYP11B1 gene that causes accumulation of 11-deoxycorticosterone, virilization and hypokalemic arterial hypertension.

Also: 11-beta-hydroxylase deficiency · 11-beta-hydroxylase deficiency

17-alpha-hydroxylase deficiency Uncommon enzymatic defect caused by alterations in the CYP17A1 gene that prevents the biosynthesis of sex steroids and cortisol, leading to hypogonadism and overproduction of mineralocorticoids.

Also: 17-alpha-hydroxylase deficiency · 17-alpha-hydroxylase deficiency

21-hydroxylase deficiency Most common cause of congenital adrenal hyperplasia in which the alteration of the CYP21A2 gene makes the normal synthesis of cortisol and aldosterone impossible, diverting the synthesis towards androgens.

Also: 21-hydroxylase deficiency · 21-hydroxylase deficiency

5-alpha reductase deficiency Autosomal recessive disorder of male sexual development characterized by the inability to convert testosterone to dihydrotestosterone, manifested by ambiguous external genitalia at birth.

Also: testicular pseudofeminization · 5-alpha-reductase deficiency

Medium chain acyl-CoA dehydrogenase deficiency The most common defect in beta-oxidation of fatty acids that predisposes to potentially fatal hypoketotic hypoglycemic crises during periods of fasting or metabolic stress.

Also: MCAD · MCADD · medium-chain acyl-CoA dehydrogenase deficiency

Very long chain acyl-CoA dehydrogenase deficiency Inherited disorder of mitochondrial oxidation of long-chain fatty acids that typically manifests with hypertrophic cardiomyopathy, severe hypoglycemia, and myopathy.

Also: VLCAD · VLCADD · very long-chain acyl-CoA dehydrogenase deficiency

Alpha-1 antitrypsin deficiency Codominant hereditary disorder where the abnormal folding of the protein synthesized in the hepatocyte prevents its systemic secretion, inducing liver cirrhosis and pulmonary emphysema.

Also: DAAT · AAT deficiency · alpha-1 antitrypsin deficiency

Carnitine palmitoyltransferase I deficiency Rare disorder that alters the initial step of the carnitine shuttle in the liver, preventing the transfer of long-chain fatty acids into the mitochondria.

Also: CPT-1 · CPT1 deficit · carnitine palmitoyltransferase I deficiency

Carnitine palmitoyltransferase II deficiency Metabolic disorder that affects the final phase of intramitochondrial transport of long-chain fatty acids, manifesting with myoglobinuria and muscle weakness precipitated by exercise.

Also: CPT-2 · CPT2 deficit · carnitine palmitoyltransferase II deficiency

Lipoprotein lipase deficiency Rare congenital error of lipid metabolism secondary to biallelic mutations in the LPL gene that prevents the normal hydrolysis of triglycerides transported by chylomicrons.

Also: LPL deficit · lipoprotein lipase deficiency

Methylmalonyl-CoA mutase deficiency Congenital metabolic defect that prevents the isomerization of methylmalonyl-CoA to succinyl-CoA, leading to accumulation of methylmalonic acid and severe systemic acidosis in childhood.

Also: classical methylmalonic aciduria · methylmalonyl-CoA mutase deficiency

Pyruvate carboxylase deficiency Rare genetic disorder characterized by the absence of the enzyme that converts pyruvate to oxaloacetate, which critically disrupts gluconeogenesis and the Krebs cycle.

Also: pyruvate carboxylase deficiency · pyruvate carboxylase deficiency

Pyruvate dehydrogenase deficiency Metabolic defect characterized by dysfunction in the multienzyme complex that decarboxylates pyruvate to acetyl-CoA, leading to congenital lactic acidosis and neurological delay.

Also: PDHD · pyruvate dehydrogenase deficiency

Propionyl-CoA carboxylase deficiency Inborn error that alters the catabolism of branched chain amino acids and odd chain fatty acids, accumulating propionyl-CoA and toxic secondary metabolites.

Also: propionic aciduria · propionyl-CoA carboxylase deficiency

Primary carnitine deficiency Genetic defect of the cell membrane carnitine transporter that causes massive urinary loss of carnitine and progressive muscle weakness and cardiomyopathy.

Also: systemic carnitine deficiency · primary carnitine deficiency

Degarelix Selective peptide antagonist of the gonadotropin-releasing hormone receptor that induces an immediate and profound suppression of serum testosterone without causing an initial release of gonadotropins.

Also: degarelix

Dehydroepiandrosterone Weak adrenal androgen synthesized in the zona reticularis that acts as a crucial precursor for the peripheral conversion of more potent male and female sex hormones.

Also: DHEA · prasterone · dehydroepiandrosterone

Dehydroepiandrosterone sulfate Adrenal androgen ester with long half-life and serum abundance that is used clinically as a reliable biomarker of androgen production by the adrenal cortex.

Also: DHEA-S · dehydroepiandrosterone sulfate

Deoxycorticosterone Precursor mineralocorticoid synthesized in the zona fasciculata and identical in potency to aldosterone but fundamentally regulated by the adrenocorticotropic hormone.

Also: DOC · 11-deoxycorticosterone · deoxycorticosterone

Deiodinase type 1 Selenoprotein expressed in the liver, kidney and thyroid that preferentially catalyzes the deiodination of the outer ring of thyroxine to generate the active hormone triiodothyronine.

Also: iodothyronine deiodinase type I · deiodinase type 1

Deiodinase type 2 Enzyme with abundant intracellular expression in the brain, pituitary and adipose tissue that efficiently converts thyroxine into locally active triiodothyronine.

Also: iodothyronine deiodinase type II · deiodinase type 2

Deiodinase type 3 Degradative selenoprotein expressed in the placenta, brain and fetal tissues that inactivates thyroid hormones by catalyzing the deiodination of the internal ring.

Also: iodothyronine deiodinase type III · deiodinase type 3

Central diabetes insipidus Water metabolism disorder characterized by the inability to synthesize or release sufficient antidiuretic hormone due to destructive lesions in the hypothalamus or posterior pituitary.

Also: neurogenic diabetes insipidus · central diabetes insipidus

Nephrogenic diabetes insipidus Inability of the renal collecting tubules to concentrate urine due to total or partial resistance or insensitivity to the physiological action of vasopressin.

Also: renal diabetes insipidus · nephrogenic diabetes insipidus

Diacylglycerol Second messenger of lipid nature that remains anchored to the cell membrane and directly activates protein kinase C in the presence of calcium ions.

Also: DAG · diglyceride · diacylglycerol · membrane diacylglycerol · second messenger lipid

Dihydrotestosterone Androgen of extreme biological power derived from testosterone by the action of the enzyme 5-alpha reductase, essential for the development of the prostate and body hair.

Also: DHT · androstanolone · dihydrotestosterone

Diiodotyrosine Iodinated amino acid residue of thyroglobulin that has two iodine atoms incorporated into its phenolic ring.

Also: DIT · diiodotyrosine

Familial dysbetalipoproteinemia Disorder characterized by the atherogenic accumulation of chylomicron remnants and IDL in plasma due to homozygous variants of apolipoprotein E with low binding affinity.

Also: type III hyperlipidemia · dysbetalipoproteinemia · familial dysbetalipoproteinemia

Proximal tubular dysfunction Generalized alteration of the reabsorption functions of the proximal convoluted tubule leading to excessive urinary excretion of amino acids, glucose, bicarbonate and phosphate.

Also: renal Fanconi syndrome · proximal tubular dysfunction

Mixed gonadal dysgenesis Disorder of sexual development characterized by chromosomal mosaicism that typically associates a unilateral dysgenetic testis and a contralateral rudimentary gonad.

Also: mosaicism 45,X/46,XY · mixed gonadal dysgenesis

Thyroid dyshormonogenesis Heterogeneous group of inherited disorders characterized by specific molecular defects in the enzymatic synthesis of thyroid hormones.

Also: congenital thyroid synthesis defect · dyshormonogenesis

Dutasteride Dual inhibitor pharmacological agent of type I and type II isoforms of the 5-alpha reductase enzyme, almost completely reducing dihydrotestosterone levels.

Also: dutasteride

Thyroid ectopia Congenital anomaly of embryonic migration of the thyroid gland that determines its definitive location at any point along the path of the thyroglossal duct.

Also: ectopic thyroid · ectopic thyroid

Somogyi Effect Asymptomatic nocturnal hypoglycemia followed by rebound hyperglycemia in the morning induced by the massive discharge of counterregulatory metabolic stress hormones.

Also: rebound hyperglycemia · Somogyi effect

Wolff-Chaikoff effect Thyroid autoregulatory phenomenon characterized by the transient inhibition of thyroid hormone synthesis induced by the administration of massive doses of inorganic iodine.

Also: iodine blockage · Wolff-Chaikoff effect

Hypothalamic-pituitary-adrenal axis Complex neuroendocrine feedback system that regulates stress response, catabolism, and immune function through the sequential secretion of corticotropin-releasing hormone, corticotropin, and adrenal glucocorticoids.

Also: HHA axis · adrenal axis · hypothalamic-pituitary-adrenal axis

Hypothalamic-pituitary-gonadal axis Endocrine control system that governs reproduction, sexual development and gametogenesis through the pulsatile release of gonadotropins and sexual steroids.

Also: HHG axis · gonadal axis · hypothalamic-pituitary-gonadal axis

Hypothalamic-pituitary-thyroid axis Homeostatic circuit responsible for maintaining stable circulating levels of thyroid hormones by modulating thyrotropin-releasing hormone and thyrotropin.

Also: HHT axis · thyroid axis · hypothalamic-pituitary-thyroid axis

Hormone response element Specific sequence of nucleotides in the promoter region of DNA where activated nuclear receptor dimers bind to initiate or repress transcription.

Also: HRE · genomic hormone binding site · hormone response element

Laron dwarfism Extreme genetic resistance to growth hormone caused by recessive mutations in its receptor that manifests with severe height delay and null levels of insulin-like growth factor 1.

Also: insensitivity to GH · Laron dwarfism

Pituitary dwarfism Disorder of height development caused by a congenital or acquired deficiency in the secretion of growth hormone during childhood.

Also: dwarfism due to GH deficiency · infantile hypopituitarism · pituitary dwarfism

Hashimoto's encephalopathy Acute or subacute neurocognitive syndrome characterized by brain dysfunction, myoclonus and extremely high levels of antithyroid antibodies, which responds dramatically to corticosteroids.

Also: steroid-sensitive encephalopathy associated with autoimmune thyroiditis · Hashimoto's encephalopathy

Conn's disease Common cause of secondary hypertension due to an adrenal adenoma that produces aldosterone autonomously and independently of the renin-angiotensin system.

Also: primary tumor aldosteronism · Conn's syndrome

Cori disease Glycogenosis type III due to deficiency of the glycogen debranching enzyme that causes accumulation of glycogen molecules with abnormally short external chains.

Also: glycogenosis type III · Forbes disease · Cori's disease

Fabry disease X-linked lysosomal disorder caused by deficiency of the enzyme alpha-galactosidase A resulting in multiorgan accumulation of globotriaosylceramide and progressive microvascular damage.

Also: diffuse corporal angiokeratoma · Fabry's disease · alpha-galactosidase A deficiency

Gaucher disease Common hereditary sphingolipidosis due to deficiency of the enzyme glucocerebrosidase that causes pathological accumulation of glucosylceramide in macrophages of the reticuloendothelial system.

Also: lipidosis due to glucosylceramide · Gaucher's disease

Maple syrup urine disease Metabolic defect due to the functional deficit of the branched-chain ketoacid dehydrogenase complex that produces toxic accumulation of leucine, isoleucine and valine.

Also: leucinosis · MSUD · maple syrup urine disease

McArdle disease Glycogenosis type V caused by the selective deficiency of the enzyme muscle glycogen phosphorylase that clinically produces exercise intolerance with intense myalgia, cramps and transient myoglobinuria.

Also: glycogenosis type V · muscle phosphorylase deficiency · McArdle's disease

Niemann-Pick disease Lysosomal disorder due to lipid deposition secondary to the deficiency of acid sphingomyelinase that causes the harmful accumulation of sphingomyelin in various tissues and progressive neurological involvement.

Also: sphingomyelin lipidosis · Niemann-Pick disease

Paget's disease of bone Chronic focal disorder of bone remodeling characterized by a massive and disorganized increase in resorption and subsequent bone neoformation that deforms and weakens the skeletal structure.

Also: osteitis deformans · Paget's disease of bone

Plummer's disease Thyroid disorder consisting of hyperfunctioning multinodular goiter where one or more nodules acquire functional autonomy, causing a clinical picture of clinically relevant thyrotoxicosis.

Also: toxic multinodular goiter · Plummer's disease

Pompe disease Glycogenosis type II characterized by a deficiency of the lysosomal enzyme alpha-1,4-glucosidase that leads to a destructive deposition of glycogen in skeletal and cardiac muscle.

Also: glycogenosis type II · acid maltase deficiency · Pompe's disease

Refsum Disease Recessive peroxisomal disorder caused by the deficiency of the enzyme phytanoyl-CoA hydroxylase that causes toxic accumulation of phytanic acid with retinitis pigmentosa and neuropathic ataxia.

Also: phytanic acid storage disease · Refsum's disease

Tangier disease Very rare hereditary metabolic disease characterized by mutations in the ABCA1 transporter that make cellular clearance of cholesterol impossible and produce almost zero circulating levels of HDL.

Also: familial alpha lipoprotein deficiency · analphalipoproteinemia · Tangier disease

Tay-Sachs disease Autosomal recessive lysosomal storage disease caused by a deficiency of the enzyme hexosaminidase A that leads to premature neurological degeneration due to accumulation of GM2 gangliosides.

Also: GM2 type 1 gangliosidosis · Tay-Sachs disease

Von Gierke's disease Glycogenosis type I caused by deficiency of the enzyme glucose-6-phosphatase that manifests clinically with severe hepatomegaly, profound fasting hypoglycemia, hyperlactatemia and hyperuricemia.

Also: glycogenosis type IA · Von Gierke's disease

Wilson's disease Genetic disorder of copper metabolism caused by mutations in the ATP7B transporter that prevent normal biliary excretion and lead to toxic accumulation in the brain and liver.

Also: hepatolenticular degeneration · Wilson's disease

Wolman's disease Lethal lysosomal disorder of early childhood caused by severe deficiency of lysosomal acid lipase that presents with steatorrhea, severe malnutrition, and massive adrenal calcification.

Also: infantile lysosomal acid lipase deficiency · Wolman's disease

Eplerenone Highly selective mineralocorticoid receptor antagonist that blocks the action of aldosterone with a significantly reduced affinity for progesterone and androgen receptors.

Also: eplerenone

Erythropoietin Glycoprotein produced predominantly by renal interstitial cells in response to cellular hypoxia that stimulates erythropoiesis in the bone marrow.

Also: EPO · renal erythropoietin · erythropoietin

Sclerostin Glycoprotein produced almost exclusively by osteocytes that acts by inhibiting the Wnt signaling pathway, reducing osteoblastogenesis and bone formation.

Also: inhibitor of the osteocytic Wnt pathway · sclerostin

Hyperglycemic hyperosmolar state Acute metabolic complication of diabetes characterized by extreme hyperglycemia, profound dehydration, and severe plasma hyperosmolarity without clinically significant ketosis.

Also: EHH · nonketotic hyperosmolar coma · hyperosmolar hyperglycemic state

Adrenal steroidogenesis Complex metabolic biosynthetic pathway that occurs in the adrenal cortex by which cholesterol is sequentially converted into specific steroid hormones.

Also: adrenal steroid synthesis · adrenal steroidogenesis

Estradiol Most powerful and biologically active estrogen in women of fertile age, synthesized predominantly by ovarian granulosa cells through the aromatization of androgens.

Also: 17-beta-estradiol · estradiol · main ovarian estrogen

Estriol Weak estrogen synthesized almost exclusively by the fetoplacental unit during pregnancy, whose blood levels serve to assess fetal well-being.

Also: free estriol · estriol

Estrona Estrogen of intermediate biological potency that constitutes the main circulating estrogenic hormone after menopause, originated mainly by peripheral conversion in adipose tissue.

Also: serum estrone · estrone

Ovarian struma Highly specialized ovarian teratoma that is predominantly composed of mature and functional thyroid tissue, with the capacity to induce autonomous peripheral thyrotoxicosis.

Also: struma ovarii · thyroid teratoma

Apparent excess of mineralocorticoids Rare autosomal recessive disorder characterized by the functional absence of the cortisol-degrading enzyme 11-beta-hydroxysteroid dehydrogenase type 2.

Also: EAM · syndrome of apparent mineralocorticoid excess

Exemestane Steroidal and irreversible type inhibitor of the aromatase enzyme that binds covalently, permanently inactivating it to reduce tissue estrogenic load.

Also: exemestane

Fibroblast growth factor 23 Phosphatonin hormone secreted by osteocytes that decreases phosphate reabsorption in the renal proximal tubule and suppresses the synthesis of calcitriol.

Also: FGF23 · fibroblast growth factor 23 · FGF-23 · phosphatenin FGF23

Premature ovarian failure Loss of normal ovarian follicular function before forty years of age that presents with hypergonadotropic amenorrhea and marked estrogen deficiency.

Also: premature ovarian failure · early menopause · premature ovarian failure

Phenylketonuria Congenital error of amino acid metabolism caused by mutations in the phenylalanine hydroxylase gene that causes neurotoxic accumulation of phenylalanine in the nervous system.

Also: PKU · phenylalanine hydroxylase deficiency · phenylketonuria

Jod-Basedow Phenomenon Paradoxical induction of a condition of hyperthyroidism or severe thyrotoxicosis triggered by massive iodine intake in individuals with nodular goiter or underlying thyroid disease.

Also: iodine-induced thyrotoxicosis · Jod-Basedow effect

Dawn phenomenon Physiological and morning elevation of blood glucose concentration due to the circadian increase in counterregulatory hormones such as cortisol and growth hormone during the last hours of sleep.

Also: Dawn phenomenon · dawn phenomenon

Finasteride Specific competitive inhibitor drug of the 5-alpha reductase type II enzyme that blocks the local conversion of testosterone into dihydrotestosterone in the prostate and hair follicles.

Also: finasteride

Phytosterolemia Genetic disorder characterized by the systemic accumulation of plant sterols due to inactivating mutations in the ABCG5 or ABCG8 transporters that prevent their biliary excretion.

Also: sitosterolemia · phytosterolemia

Folistatin Secretory glycoprotein that binds with high affinity to activin, neutralizing its biological activity and indirectly regulating the release of gonadotropins.

Also: activin-binding protein · follistatin

Bone alkaline phosphatase Isoform of the alkaline phosphatase enzyme located in the membrane of osteoblasts, active in the extracellular osteoid mineralization processes.

Also: BALP · bone alkaline phosphatase · FAO · specific bone phosphatase

Phospholipase C Membrane effector enzyme that hydrolyzes phosphatidylinositol 4,5-bisphosphate to generate the second messengers inositol triphosphate and diacylglycerol.

Also: PLC · phosphoinositide phosphodiesterase · phospholipase C

Oxidative phosphorylation Mitochondrial enzymatic process in which the free energy generated by the proton gradient is coupled to the synthesis of adenosine triphosphate by the ATP synthase complex.

Also: mitochondrial ATP synthesis · oxidative phosphorylation

Essential fructosuria Benign and asymptomatic inborn error of fructose metabolism due to deficiency of the hepatic fructokinase enzyme leading to direct renal excretion of fructose.

Also: benign fructosuria · essential fructosuria

Galactosemia Inherited metabolic disorder caused by deficiency of the enzyme galactose-1-phosphate uridyltransferase that results in severe systemic organ toxicity after ingestion of milk or dairy products.

Also: classical galactosemia · GALT deficiency · galactosemia

Ganirelix Synthetic gonadotropin-releasing hormone antagonist for subcutaneous administration that acts by immediately blocking the release of gonadotropins in a dose-dependent manner.

Also: ganirelix

Gastrin Polypeptide hormone produced by the G cells of the gastric antrum and duodenum that potently stimulates the secretion of hydrochloric acid by the parietal cells.

Also: gastric gastrin · gastrin

Diabetic gastroparesis Motor dysfunction characterized by a marked and chronic delay in gastric emptying in the absence of intrinsic or extrinsic mechanical obstruction, secondary to autonomic neuropathy.

Also: diabetic gastric paralysis · diabetic gastroparesis

Ghrelina Orexigenic peptide synthesized mainly by the oxyntic cells of the stomach that stimulates appetite and the secretion of growth hormone.

Also: hunger hormone · ghrelin

Gigantism Disorder characterized by excessive and accelerated longitudinal growth of the long bones secondary to an excess of growth hormone before the fusion of the bony epiphyses.

Also: pituitary gigantism · gigantism

Pineal gland Small endocrine structure of the diencephalon responsible for the biosynthesis and rhythmic secretion of melatonin under the direct influence of the daily light cycle.

Also: cerebral epiphysis · pineal gland

Corticosteroid-binding globulin Plasma transporter protein of the serpin family that binds preferentially and with high affinity to glucocorticoids and progesterone.

Also: CBG · transcortin · corticosteroid-binding globulin

Sex hormone-binding globulin Transport glycoprotein synthesized in the liver that binds with high affinity to testosterone and estradiol, regulating their biologically active free fraction.

Also: SHBG · sex steroid binding globulin · sex hormone-binding globulin

Thyroxine-binding globulin Main plasma transport glycoprotein that carries the largest fraction of circulating thyroid hormones into the bloodstream in a reversible manner.

Also: TBG · thyroxine binding globulin · thyroxine-binding globulin

Glucagonoma Pancreatic alpha cell neoplasm that produces massive amounts of glucagon, typically manifested by necrolytic migratory erythema, new-onset diabetes, and profound wasting.

Also: alpha cell tumor · glucagonoma

Glycogenogenesis Cytosolic anabolic pathway that synthesizes polymeric glycogen from activated glucose precursors, predominantly stimulated by nutrient abundance signals.

Also: glycogen synthesis · glycogenesis · glycogenesis

Glycogenolysis Catabolic process that consists of the enzymatic degradation of glycogen stored in the liver or muscles in order to release glucose-1-phosphate or free glucose into the bloodstream.

Also: glycogen degradation · glycogenolysis

Glycogenosis Set of congenital diseases caused by deficiencies of enzymes involved in glycogen metabolism that cause its accumulation or abnormal structure mainly in the liver and muscle.

Also: glycogen storage disease · GSD · glycogenosis

Glycogenosis type IV Autosomal recessive defects caused by mutations in the glycogen branching enzyme that lead to tissue deposition of insoluble glycogen polymers with few and long branches.

Also: Andersen's disease · amylopectinosis · glycogen storage disease type IV

Glycogenosis type VI Glycogen metabolism disorder due to deficiency of the enzyme hepatic glycogen phosphorylase that manifests clinically with benign hepatomegaly and mild hypoglycemia.

Also: Hers disease · Hers' disease

Glycogenosis type VII Metabolic muscle glycogenosis caused by deficiency of the phosphofructokinase enzyme that clinically presents with intolerance to muscular effort and hemolysis of variable intensity.

Also: Tarui disease · Tarui's disease

Glycolysis Cytoplasmic catabolic pathway that oxidizes one molecule of glucose to two molecules of pyruvate with the net generation of chemical energy in the form of adenosine triphosphate.

Also: Embden-Meyerhof route · anaerobic degradation of glucose · glycolysis

Glucotoxicity Deleterious and harmful effect caused by chronic and sustained hyperglycemia on the secretory capacity of pancreatic beta cells and peripheral sensitivity to insulin.

Also: glucose toxicity · glucotoxicity

Glutaricuria type 1 Autosomal recessive neurometabolic metabolic disorder caused by deficiency of the enzyme glutaryl-CoA dehydrogenase, clinically manifested by dystonia and acute striatal damage.

Also: glutaric aciduria type I · glutaric aciduria type I

Gonadarche Maturational phase that marks the physical beginning of puberty itself due to the reactivation of the pulsatile secretion of gonadotropins by the pituitary gland.

Also: gonadarche

Human chorionic gonadotropin Placental glycoprotein that maintains the viability of the corpus luteum during the first weeks of pregnancy to ensure the continuous production of progesterone.

Also: hCG · chorionic gonadotropin · human chorionic gonadotropin

Pituitary gonadotropins Glycoprotein hormones secreted by the gonadotroph cells of the anterior pituitary that act on the testes or ovaries to regulate gametogenic maturation and steroidogenesis.

Also: FSH and LH · serum gonadotropins · pituitary gonadotropins

Goserelin Biodegradable sustained-release GnRH receptor agonist implant useful in the profound suppression of gonadal steroids in hormone-dependent pathologies.

Also: goserelin

Hereditary hemochromatosis Autosomal recessive genetic disorder characterized by excessive intestinal absorption of iron with consequent destructive tissue deposition in organs such as the liver, pancreas and myocardium.

Also: classical hemochromatosis · primary iron overload · hereditary hemochromatosis

Idiopathic hyperandrogenism Clinical condition characterized by cutaneous manifestations of androgen excess in women with normal circulating androgen concentrations and ovarian function.

Also: idiopathic hirsutism · idiopathic hyperandrogenism

Familial hypocalciuric hypercalcemia Autosomal dominant genetic alteration of calcium homeostasis due to inactivating mutations in the calcium sensing receptor gene in parathyroid glands and kidney.

Also: HHF · benign familial hypercalcemia · familial hypocalciuric hypercalcemia

Autosomal dominant hypercalciuria Disorder characterized by activating mutations in the calcium sensing receptor gene that induce inappropriate suppression of parathyroid hormone and severe hypercalciuria with hypocalcemia.

Also: HAD · autosomal dominant hypocalcemia with hypercalciuria

Familial hypercholesterolemia Autosomal dominant genetic disorder caused by mutations in the LDL receptor gene that produces severe and premature elevations of plasma cholesterol and early cardiovascular events.

Also: HF · type IIa hyperlipidemia · familial hypercholesterolemia

Congenital hyperinsulinism Heterogeneous group of genetic disorders that cause persistent and inappropriate secretion of insulin by pancreatic beta cells despite critically low levels of blood glucose.

Also: neonatal nesidioblastosis · congenital hyperinsulinism

Combined familial hyperlipidemia Common multigenic lipid disorder characterized by variable elevations of serum cholesterol and triglycerides in the same individual or his or her immediate family, associated with a high atherogenic risk.

Also: HLFC · familial combined hyperlipidemia

Primary hyperoxaluria Innate error of glyoxylate metabolism that causes massive endogenous overproduction of oxalate, deposited in the form of calcium oxalate in the kidneys and joints.

Also: primary oxalosis · primary hyperoxaluria

Primary pigmented micronodular hyperplasia Autonomous bilateral adrenal endocrinopathy characterized by multiple dark pigmented millimetric nodules in the adrenal cortex, frequently associated with the Carney Complex.

Also: PPNAD · primary pigmented nodular adrenocortical disease

Congenital adrenal hyperplasia Group of autosomal recessive disorders characterized by specific enzymatic deficiencies in adrenal steroidogenesis that lead to an excess of androgenic precursors and a deficiency of glucocorticoids.

Also: HSC · congenital steroidogenesis defect · congenital adrenal hyperplasia

Late-onset congenital adrenal hyperplasia Non-classical and mild form of 21-hydroxylase deficiency that manifests clinically in puberty or young adulthood with signs of androgenic excess such as hirsutism and menstrual irregularities.

Also: Non-classical HSC · late-onset congenital adrenal hyperplasia

Congenital salt-losing adrenal hyperplasia Severe phenotypic variant of 21-hydroxylase deficiency characterized by an absolute deficiency of aldostorone and cortisol that causes dehydrating crises and neonatal shock.

Also: HSC salt loser · salt-wasting congenital adrenal hyperplasia

Simple congenital virilizing adrenal hyperplasia Clinical variant of 21-hydroxylase deficiency where sufficient enzymatic activity is preserved to prevent massive salt loss but an androgenic excess persists, causing virilization in girls.

Also: Classic virilizing HSC · simple virilizing congenital adrenal hyperplasia

ACTH-independent bilateral macronodular adrenal hyperplasia Rare variety of endogenous hypercortisolism syndrome characterized by the presence of large bilateral autonomous adrenal nodules stimulated by aberrant receptors.

Also: AIMAH · ACTH-independent macronodular adrenal hyperplasia

Hyperchylomicronemia Severe metabolic alteration of lipid clearance characterized by deficiencies of lipoprotein lipase or its activating cofactor, which induces massive levels of triglycerides and recurrent pancreatitis.

Also: hyperlipidemia type I · familial chylomicronemia · hyperchylomicronemia

Ovarian hyperthecosis Alteration of the ovarian stroma characterized by diffuse nests of luteinized androgen-producing thecal cells that cause severe virilization and extreme insulin resistance.

Also: ovarian thecosis · ovarian hyperthecosis

Subclinical hyperthyroidism Clinical condition in which the plasma concentration of thyroid-stimulating hormone is suppressed or undetectable despite normal concentrations of free thyroid hormones.

Also: mild hyperthyroidism · subclinical hyperthyroidism

Hypervitaminosis D State of endocrine and metabolic toxicity caused by massive intakes of vitamin D, characterized by severe hypercalcemia, hypercalciuria and generalized metastatic calcifications.

Also: vitamin D poisoning · vitamin D toxicity

Hypervolemia Expansion of the total volume of fluid in the intravascular compartment of the body, usually manifested by vascular congestion and generalized edema.

Also: volume overload · intravascular hypervolemia · hypervolemia

Granulomatous hypophysitis Chronic destructive inflammation of the pituitary gland characterized by the presence of non-caseating granulomas with multinucleated giant cells, of idiopathic or systemic etiology.

Also: giant cell hypophysitis · granulomatous hypophysitis

Lymphocytic hypophysitis Autoimmune inflammation of the pituitary gland that typically occurs in women during pregnancy or late puerperium, characterized histologically by lymphocyte infiltrates.

Also: autoimmune hypophysitis · lymphocytic hypophysitis

Hereditary hypophosphatemia Genetic disorder of mineral metabolism characterized by renal loss of phosphate and defective bone mineralization due to alterations in the regulatory mechanisms of fibroblast growth factor 23.

Also: familial hypophosphatemic rickets · hereditary hypophosphatemia

Congenital hypothyroidism Severe thyroid hormone deficiency present from birth, secondary to dysgenesis or dyshormonogenesis of the thyroid gland that, without timely treatment, leads to severe delay in neurocognitive development.

Also: sporadic cretinism · congenital hypothyroidism

Subclinical hypothyroidism Biochemical state characterized by elevations in thyroid-stimulating hormone in the presence of completely normal plasma concentrations of free thyroid hormones.

Also: mild hypothyroidism · subclinical hypothyroidism

Hypovitaminosis D Deficiency or systemic insufficiency of circulating vitamin D that compromises normal bone mineralization, inducing rickets in children and osteomalacia in adults.

Also: vitamin D deficiency · vitamin D deficiency

Homocystinuria Hereditary transsulfuration disorder characterized by severe elevations in plasma and urinary homocysteine due to cystathionine beta-synthase deficiency.

Also: CBS deficiency · classical homocystinuria · homocystinuria

Corticotropin-releasing hormone Neuropeptide synthesized in the paraventricular nucleus of the hypothalamus that acts as the main initiator of the neuroendocrine response to stress.

Also: CRH · FRC · corticotropin-releasing hormone

Gonadotropin-releasing hormone Hypothalamic decapeptide secreted in a pulsatile manner that regulates the synthesis and pituitary secretion of luteinizing hormone and follicle-stimulating hormone.

Also: GnRH · LHRH · gonadotropin-releasing hormone

Growth hormone-releasing hormone Hypothalamic peptide that stimulates gene transcription and exocytosis of growth hormone in the somatotroph cells of the anterior pituitary.

Also: GHRH · somatocrinin · growth hormone-releasing hormone

Thyrotropin-releasing hormone Hypothalamic tripeptide that stimulates the synthesis and secretion of thyroid-stimulating hormone and prolactin in the anterior pituitary.

Also: TRH · thyrotropin-releasing factor · thyrotropin-releasing hormone

Trophic hormone Chemical messenger whose main function is to stimulate the growth, survival and secretory activity of another peripheral endocrine gland.

Also: stimulating hormone · trophic factor · trophic hormone

Free thyroid hormones Fraction not bound to plasma transport proteins of thyroxine and triiodothyronine that is the only one capable of diffusing to target tissues to exert biological actions.

Also: T4 free and T3 free · free hormones · free thyroid hormones

Adrenal incidentaloma Tumor mass located unexpectedly and incidentally in one of the adrenal glands during an abdominal imaging study performed for unrelated diagnostic reasons.

Also: incidental adrenal mass · adrenal incidentaloma

Aromatase inhibitors Group of drugs for oncoendocrine use that block the enzymatic conversion of androgens into estrogens, reducing the circulating concentration of estradiol.

Also: aromatase inhibitors · aromatase inhibitors

Inhibin A Heterodimeric glycoprotein secreted by the corpus luteum that selectively inhibits the pituitary synthesis and secretion of follicle-stimulating hormone during the late luteal phase.

Also: luteal inhibin · inhibin A

Inhibin B Glycoprotein secreted by Sertoli cells in men and by granulosa cells in women, clinically useful as a direct marker of follicular reserve and testicular function.

Also: follicular inhibin · inhibin B

Thyroid-stimulating immunoglobulins Autoantibodies directed against the thyrotropin receptor that constitutively activate the stimulatory cellular pathway, triggering the hyperfunctioning diffuse goiter characteristic of Graves' disease.

Also: TSI · TSH receptor-stimulating antibodies · thyroid-stimulating immunoglobulins

Inositol triphosphate Soluble second messenger that diffuses through the cytoplasm and binds to ligand-coupled calcium channels in the endoplasmic reticulum, causing massive release of intracellular calcium.

Also: IP3 · inositol 1,4,5-trisophate · inositol trisphosphate · inositol 1,4,5-triphosphate · cellular calcium releaser

Secondary adrenal insufficiency Hypofunction of the adrenal cortex due to inadequate or no production of adrenocorticotropic hormone at the level of the anterior pituitary.

Also: secondary hypoadrenalism · secondary adrenal insufficiency

Tertiary adrenal insufficiency Glucocorticoid deficiency caused by the alteration or suppression of the synthesis of corticotropin-releasing hormone at the level of the hypothalamus, commonly associated with the abrupt cessation of prolonged corticotherapy.

Also: tertiary hypoadrenalism · tertiary adrenal insufficiency

Plasma insulin Measurable plasma or serum concentration of active free insulin present in the bloodstream of an individual.

Also: serum insulin · plasma insulin level · insulinemia

Hereditary fructose intolerance Autosomal recessive disorder of carbohydrate metabolism caused by aldolase B deficiency that produces acute liver and kidney damage after ingestion of fructose or sucrose.

Also: aldolase B deficiency · hepatic aldolase B · hereditary fructose intolerance

Irisina Myokin released by skeletal muscle during physical exercise that induces the conversion of white adipose tissue into a beige or brown phenotype with high thermogenic capacity.

Also: exercise hormone · irisin

LADA A form of latent autoimmune diabetes in adults characterized by a slow clinical onset that mimics type 2 diabetes but is associated with the presence of antibodies against glutamic acid decarboxylase.

Also: latent autoimmune diabetes in adults · latent autoimmune diabetes in adults

Lanreotide Synthetic analogue peptide of somatostatin formulated for prolonged release, used therapeutically in acromegaly and gastroenteropancreatic neuroendocrine tumors.

Also: lanreotide

Lecithin-cholesterol acyltransferase Plasma enzyme that esterifies free cholesterol on the surface of high-density lipoproteins, facilitating maturation and reverse cholesterol transport.

Also: LCAT · lecithin-cholesterol acyltransferase

Leprechaunism Fatal genetic disorder characterized by extreme insulin resistance due to severe biallelic mutations in the insulin receptor gene that cause a severe dysmorphic phenotype and failure to thrive.

Also: Donohue syndrome · leprechaunism

Leptin Adipocin secreted by white adipose tissue in proportion to fat mass that acts on the hypothalamus, decreasing appetite and increasing energy expenditure.

Also: satiety hormone · leptin

Letrozole Third-generation non-steroidal selective inhibitor of the aromatase enzyme used in the treatment of estrogen-dependent breast cancer and in the induction of ovulation.

Also: letrozole

Leuprolide Synthetic GnRH receptor agonist agent that after initial stimulation causes massive desensitization of pituitary receptors, inducing therapeutic hypogonadotropic hypogonadism.

Also: leuprolide acetate · leuprolide

Nuclear factor kappa B activating receptor ligand Cytocin produced by osteoblasts and osteocytes that binds to its specific receptor in osteoclastic precursors, stimulating their differentiation and resorptive activation.

Also: RANKL · RANK ligand · receptor activator of nuclear factor kappa-B ligand

Lipodystrophy Pathological alteration of the distribution and normal development of the body's adipose tissue, which can be congenital or acquired, localized, partial or generalized.

Also: acquired or congenital lipodystrophy · lipodystrophy

Berardinelli-Seip congenital lipodystrophy Rare variant of autosomal recessive lipodystrophy characterized by the almost total absence of metabolically active adipose tissue from birth and extreme insulin resistance.

Also: Seip-Lawrence syndrome · Berardinelli-Seip congenital lipodystrophy

Acquired generalized lipodystrophy Almost total and progressive loss of subcutaneous adipose tissue beginning during childhood or adolescence, commonly associated with autoimmune disorders and severe insulin resistance.

Also: Lawrence syndrome · acquired generalized lipodystrophy

Acquired partial lipodystrophy Metabolic disorder characterized by the gradual and symmetrical loss of subcutaneous fat of the face and upper trunk associated with low levels of complement C3.

Also: Barraquer-Simons syndrome · acquired partial lipodystrophy

Lipogenesis Metabolic synthesis pathway of fatty acids and their subsequent esterification with glycerol to constitute reserve triglycerides in the liver and adipose tissue.

Also: lipid synthesis · lipogenesis

Lipolysis Enzymatic degradation of triglycerides stored in the lipid droplets of white adipose tissue to release free fatty acids and glycerol into the systemic circulation.

Also: lipid hydrolysis · lipolysis

High density lipoprotein Lipoprotein particle involved in the reverse transport of cholesterol from peripheral tissues back to the liver for subsequent biliary excretion.

Also: HDL · high density lipoprotein · high-density lipoprotein

Low density lipoprotein Lipoprotein particle responsible for transporting cholesterol from the liver to the peripheral tissues, the excess of which is strongly associated with the development of atheroma plaques.

Also: LDL · low density lipoprotein · low-density lipoprotein

Intermediate density lipoprotein Transitory metabolic product derived from the partial degradation of very low density lipoproteins by capillary lipoprotein lipase.

Also: IDL · intermediate-density lipoprotein

Very low density lipoprotein Lipoprotein synthesized and secreted by the liver whose function is to distribute triglycerides of endogenous origin to extrahepatic tissues.

Also: VLDL · very low-density lipoprotein

Lipotoxicity Abnormal and harmful accumulation of active lipid metabolites in non-adipose tissues that impairs cellular function and promotes altered cell signaling and apoptosis.

Also: fatty acid toxicity · lipotoxicity

Myocardial lipotoxicity Deleterious accumulation of lipid intermediates in myocardial tissue that impairs contractile function and promotes mitochondrial dysfunction and cell death in altered metabolic states.

Also: lipotoxic cardiomyopathy · myocardial lipotoxicity

Lysinuria Defect in the transcellular transport of lysine in the kidney and intestine that generates massive urinary clearance of said essential amino acid.

Also: hereditary lysinuria · lysinuria

Diabetic macroangiopathy Acceleration of obstructive atherosclerotic processes in medium and large caliber arteries that occurs in long-standing diabetic patients.

Also: diabetic macrovascular disease · diabetic macroangiopathy

Macroprolactinemia Presence of prolactin polymer complexes linked to high molecular weight immunoglobulins that artificially raise serum prolactin without causing typical hyperprolactinemic symptoms.

Also: prolactin bound to IgG · macroprolactinemia

Melatonin Indoleamine hormone synthesized from tryptophan in the pineal gland that acts as a crucial regulator of circadian rhythms and the sleep-wake cycle.

Also: N-acetyl-5-methoxytryptamine · melatonin

Metyrapone Pharmacological agent that selectively inhibits the enzyme 11-beta-hydroxylase, blocking the final synthesis phase of cortisol, used in diagnostic tests and control of hypercortisolism.

Also: metyrapone · metyrapone

Diabetic microangiopathy Characteristic ultrastructural and histological damage of small capillary blood vessels in patients with poorly controlled diabetes, characterized by diffuse thickening of their basement membrane.

Also: diabetic microvascular disease · diabetic microangiopathy

Central pontine myelinolysis Dominant anatomical variant of osmotic demyelination characterized by the symmetrical destruction of myelin sheaths in the cerebral pons.

Also: central pontine myelinolysis

Thyrotoxic myopathy Progressive proximal muscle weakness and fibrillar atrophy directly induced by persistent excess of circulating thyroid hormones.

Also: thyrotoxic muscle weakness · thyrotoxic myopathy

Mitotano Antineoplastic drug with potent adrenolytic activity that selectively induces necrosis of the cells of the adrenal cortex and is used in advanced adrenal carcinoma.

Also: mitotane · mitotane

Selective androgen receptor modulators Synthetic compounds that bind to the androgen receptor showing notable tissue selectivity, promoting muscle anabolism without inducing prostatic hypertrophy.

Also: MRSA · selective androgen receptor modulators

MODY Heterogeneous group of monogenic disorders of insulin secretion characterized by autosomal dominant inheritance and primary dysfunction of pancreatic beta cells with onset at young ages.

Also: mature inheritance diabetes in the young · maturity onset diabetes of the young

Monoiodotyrosine Intermediate peptide residue of thyroglobulin that has a single iodine atom attached to its tyrosyl ring.

Also: MIT · monoiodotyrosine

Motilina Digestive peptide of twenty-two amino acids that stimulates the migratory motor complex of the gastrointestinal tract during periods of fasting.

Also: duodenal motilin · motilin

Mucopolysaccharidosis Group of lysosomal diseases characterized by the progressive intracellular accumulation of glycosaminoglycans due to the deficiency of specific hydrolase enzymes required for their degradation.

Also: MPS · glycosaminoglycan deposition · mucopolysaccharidosis

Diabetic nephropathy Chronic and progressive kidney disease of microvascular origin that develops in long-standing diabetic patients, characterized by the appearance of persistent microalbuminuria.

Also: diabetic kidney disease · diabetic nephropathy · diabetic glomerulosclerosis

Multiple endocrine neoplasia type 1 Autosomal dominant hereditary disorder caused by mutations in the MEN1 gene that predisposes to the simultaneous development of tumors in the parathyroid, endocrine pancreas and anterior pituitary.

Also: Wermer syndrome · MENU 1 · multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 2A Autosomal dominant hereditary syndrome caused by mutations of the RET proto-oncogene, characterized by medullary thyroid carcinoma, pheochromocytoma and primary hyperparathyroidism.

Also: Sipple syndrome · MENU 2A · multiple endocrine neoplasia type 2A

Multiple endocrine neoplasia type 2B Aggressive phenotypic variant of MEN syndrome caused by specific point mutations of RET, characterized by medullary thyroid carcinoma, pheochromocytoma and multiple mucosal neuromas.

Also: Wagenmann-Froboese syndrome · MENU 2B · multiple endocrine neoplasia type 2B

Nesidioblastosis Diffuse proliferation and hyperplasia of pancreatic islet cells from the epithelium of the exocrine ducts that clinically present with hypoglycemia due to endogenous hyperinsulinism.

Also: islet cell hyperplasia · nesidioblastosis

Octreotide Long-acting synthetic analogue of somatostatin with high affinity for the subtype 2 receptor, effective in suppressing the release of growth hormone and digestive hormones.

Also: octreotide

RET Oncogene Tyrosine kinase membrane receptor whose activating germline or somatic mutations drive the pathogenesis of medullary thyroid carcinomas and multiple endocrine neoplasias type 2.

Also: RET proto-oncogene · RET oncogene

Thyroid orbitopathy Autoimmune inflammatory condition of the extraocular orbital tissues and retrobulbar fat closely associated with Graves' disease.

Also: Graves' ophthalmopathy · thyroid eye disease

Osilodrostat Potent oral inhibitor of the 11-beta-hydroxylase enzyme used specifically for the rapid control of excessive cortisol production in Cushing's syndrome of various etiologies.

Also: osilodrostat

Osteitis fibrosa cystica Advanced and destructive bone complication of chronic hyperparathyroidism characterized by intense bone resorption with fibrous replacement of the marrow spaces and formation of bone cysts.

Also: Recklinghausen hyperparathyroid bone disease · cystic fibrosa osteitis · uremic Von Recklinghausen bone disease

Osteocalcin Abundant non-collagenous protein of the bone matrix synthesized by osteoblasts dependent on vitamin K that serves as a direct clinical marker of bone formation.

Also: BGP · Gla-containing bone matrix protein · osteocalcin

Albright's Hereditary Osteodystrophy Characteristic phenotype of short stature, round face, shortening of metacarpals and subcutaneous calcifications associated with generalized resistance to hormones that act through receptors coupled to the Gs alpha subunit.

Also: AHO · Albright's hereditary osteodystrophy

Renal osteodystrophy Set of morphological alterations and bone remodeling that occur in patients with advanced chronic renal failure, due to secondary hyperparathyroidism and calcitriol deficiency.

Also: renal bone disease · renal osteodystrophy · uremic bone disease

Osteoprotegerin Decoy receptor secreted by osteoblasts that binds to RANKL, preventing its interaction with RANK and inhibiting active bone resorption mediated by osteoclasts.

Also: OPG · osteoprotegerin

Oxytocin Nonaneuropituitary peptide that stimulates contractions of the uterine myometrium during childbirth and milk ejection by the myoepithelial cells of the mammary gland.

Also: oxytocin · birth hormone · pitocin · synthetic oxytocic hormone · contraction inducer

Paraganglioma Neuroendocrine neoplasia originating in the chromaffin cells of the sympathetic or parasympathetic ganglia outside the adrenal medulla, which can actively secrete catecholamines.

Also: extraadrenal pheochromocytoma · paraganglioma

Thyrotoxic periodic paralysis Acute complication characterized by paroxysmal episodes of flaccid paralysis and hypokalosis secondary to massive displacement of intracellular potassium in the context of thyrotoxicosis.

Also: hypokalemic thyrotoxic paralysis · thyrotoxic periodic paralysis

Pasireotide New generation multireceptor somatostatin receptor analogue with increased affinity for receptor subtype 5, used in the therapeutic management of refractory Cushing's disease.

Also: pasireotide

Pegvisomant Recombinant selective antagonist of growth hormone receptors that prevents receptor dimerization, effectively reducing serum levels of insulin-like growth factor 1 in acromegalic patients.

Also: pegvisomant

Pendrine Chloride/iodide anion transporter located in the apical membrane of thyrocytes, actively involved in the efflux of iodine into the follicular colloidal space.

Also: apical iodine exchanger · pendrin · apical Cl-/HCO3- exchanger · SLC26A4

C-peptide Connecting peptide equimolar released into the bloodstream along with insulin during the cleavage of proinsulin, useful as a marker of the endogenous functional reserve of beta cells.

Also: connecting peptide · C-peptide

Glucose-dependent insulinotropic peptide Incretin hormone secreted by the K cells of the small intestine that stimulates insulin secretion after ingesting nutrients.

Also: GIP · gastric inhibitory peptide · glucose-dependent insulinotropic polypeptide

Glucagon-like peptide type 1 Incretin synthesized by L cells of the ileum that enhances glucose-dependent insulin secretion, suppresses glucagon and delays gastric emptying.

Also: GLP-1 · glucagon-1 analogue peptide · glucagon-like peptide-1

Thyroid peroxidase Enzyme bound to the apical membrane of thyrocytes that catalyzes in a coupled manner the oxidation of iodide, the iodination of tyrosyl residues and the subsequent coupling to form thyroid hormones.

Also: TPO · thyroid peroxidase

Diabetic foot Destructive clinical alteration that affects the soft tissues and bone structures of the foot in diabetic patients, caused by the combination of peripheral ischemia, neuropathy and microtrauma.

Also: diabetic foot ulceration · diabetic foot

Pinealoma Neoplasia originating from the pinealocytes of the pineal gland that can compress the Sylvian aqueduct causing obstructive hydrocephalus and visual dysfunction of vertical gaze.

Also: pineal parenchyma tumor · pinealoma

Primary polydipsia Pathological and excessive water consumption that physiologically suppresses the release of vasopressin, inducing massive aqueous polyuria and dilutional hyponatremia in the absence of an initial organic defect of the vasopressin axis.

Also: potomania · psychogenic polydipsia · primary polydipsia

Acute intermittent porphyria Acute autosomal dominant metabolic disorder secondary to porphobilinogen deaminase deficiency that triggers systemic neurological crises and intense abdominal pain of paroxysmal onset.

Also: PAI · acute hepatic porphyria · acute intermittent porphyria

Porphyria cutanea Tarda Most common cause of porphyria due to a functional reduction of uroporphyrinogen decarboxylase, clinically characterized by extreme cutaneous photosensitivity with epidermal fragility and blisters in exposed areas.

Also: PCT · cutaneous porphyria · porphyria cutanea Tarda

PPAR-alpha Nuclear receptor expressed predominantly in the liver that modulates the transcription of genes for beta-oxidation of fatty acids and triglyceride clearance.

Also: PPAR-alpha · PPAR-alpha receptor · peroxisome proliferator-activated receptor alpha

PPAR-delta Nuclear receptor isomer involved in the regulation of cellular energy consumption, lipid oxidation in skeletal muscle and general metabolic homeostasis.

Also: PPAR-beta · peroxisome proliferator-activated receptor delta

Pregnenolone Steroid derived directly from the cleavage of cholesterol that serves as the common initial precursor for all endogenous steroid hormones in the body.

Also: pregnenolone

Preprohormone Initial precursor molecule synthesized in ribosomes that contains a hydrophobic signal sequence at its amino terminus, which is cleaved during its passage to the endoplasmic reticulum.

Also: primary precursor · pre-prohormone

Progesterone Twenty-one carbon steroid hormone secreted by the corpus luteum and placenta, essential for endometrial preparation and successful maintenance of pregnancy.

Also: ovarian progestin · progesterone

Prohormone Polypeptide precursor of a hormone that lacks significant biological activity and requires specific proteolytic cleavage to convert to its active form.

Also: pro-hormone · inactive hormonal precursor

Proinsulin Linear polypeptide precursor of insulin that undergoes specific folding through the formation of disulfide bridges in the endoplasmic reticulum before being packaged into secretory granules.

Also: pro-insulin · proinsulin

Prolactinoma Benign tumor originating in the lactotroph cells of the adenohypophysis that secretes excessive amounts of prolactin, causing amenorrhea, galactorrhea and secondary hypogonadism.

Also: lactotropic adenoma · prolactinoma

Proopiomelanocortin Complex polypeptide precursor that undergoes specific proteolytic processing to give rise to corticotropin, melanotropins and beta-endorphins.

Also: POMC · pro-opiomelanocortin

Amino-terminal propeptide of procollagen type I Peptide fragment cleaved extracellularly during the biosynthesis of type I collagen, used as a highly sensitive serum marker of bone formation and remodeling.

Also: PINP · procollagen type I N-propeptide

Uncoupling protein 1 Mitochondrial transporter protein exclusive to brown adipose tissue that dissipates the electrochemical proton gradient by generating heat instead of adenosine triphosphate.

Also: UCP1 · thermogenin · uncoupling protein 1

Vitamin D binding protein Multifunctional plasma transporter glycoprotein that binds to vitamin D and its metabolites, facilitating its circulation and delivery to target organs.

Also: DBP · vitamin D binding globulin · vitamin D-binding protein

PCSK9 protein Secreted enzyme that binds to the LDL receptor and promotes its intracellular lysosomal degradation, negatively regulating the availability of these receptors on the hepatocyte membrane.

Also: proprotein convertase subtilisin/kexin type 9 · PCSK9

Protein kinase A Cyclic adenosine monophosphate-dependent multifunctional enzyme that phosphorylates specific serine and threonine residues on cellular target proteins.

Also: PKA · cAMP-dependent kinase · protein kinase A

Protein kinase C Family of calcium and lipid-dependent kinases that modulate cell growth, gene transcription and secretion processes through the phosphorylation of intracellular substrates.

Also: PKC · diacylglycerol-dependent kinase · protein kinase C

Cholesteryl ester transport protein Plasma protein that catalyzes the transfer of cholesterol esters from high-density lipoproteins to triglyceride-rich lipoproteins.

Also: CETP · cholesteryl ester transfer protein

Pseudohypoaldosteronism type 1 Disorder characterized by systemic resistance to aldosterone mediated by inactivating mutations in the mineralocorticoid receptor or epithelial sodium channels.

Also: PHA 1 · pseudohypoaldosteronism type 1

Pseudohypoaldosteronism type 2 Rare inherited disorder of ion transport characterized by hyperkalemia, metabolic acidosis, and hypertension despite normal levels of glomerular filtration rate.

Also: PHA 2 · pseudohypoaldosteronism type 2 · PHA II

Pubarchy Physiological appearance of pubic and axillary hair during puberty, fundamentally triggered by the secretion and peripheral action of androgens of gonadal or adrenal origin.

Also: pubarche

Central precocious puberty Development of secondary sexual characteristics before the age of eight in girls or nine years in boys due to premature and gonadotropin-dependent activation of the hypothalamic-pituitary-gonadal axis.

Also: true precocious puberty · central precocious puberty

Peripheral precocious puberty Development of secondary sexual characteristics independently of the pituitary secretion of gonadotropins, secondary to endogenous or exogenous sources of sexual steroids.

Also: gonadotropin-independent precocious puberty · precocious pseudopuberty · peripheral precocious puberty

Delayed puberty Absence of the beginning of the development of secondary sexual characteristics at a chronological age that exceeds the normal standard deviations for the general population, generally set at thirteen years in girls and fourteen years in boys.

Also: pubertal delay · delayed puberty

Set point Predetermined level or range of a physiological variable, such as temperature or blood glucose, that the endocrine system and the central nervous system actively try to defend through effector mechanisms.

Also: set point · homeostatic reference value · physiological threshold

Chylomicron Large lipoprotein synthesized in the cells of the intestinal epithelium responsible for transporting lipids of dietary origin to the general circulation.

Also: plasma chylomicrons · chylomicron

Rathke's pouch cyst Benign intrasellar or suprasellar cystic lesion caused by the persistence and accumulation of mucus in the remnant of Rathke's embryological pouch.

Also: colloid pituitary cyst · Rathke's cleft cyst

G protein-coupled receptor Superfamily of membrane receptors with seven transmembrane domains that transmit extracellular signals to the cell interior by activating heterotrimeric G proteins.

Also: GPCR · seven transmembrane domain receptor · G-protein coupled receptor

Peroxisome proliferator-activated receptor gamma Master nuclear transcription factor that governs the development of adipocytes and modulates genes involved in lipid homeostasis and insulin sensitivity.

Also: PPAR-gamma · PPAR-range receiver · peroxisome proliferator-activated receptor gamma

Androgen receptor Nuclear receptor activated by steroidal androgens such as testosterone and dihydrotestosterone that promotes the transcription of genes necessary for male sexual development and function.

Also: AR · androgen receptor · androgen receptor

Estrogen receptor alpha Estrogen receptor isoform strongly expressed in the uterus, mammary gland, hypothalamus and bone that dominantly governs female reproductive development.

Also: ER-alpha · estrogen receptor alpha · estrogen receptor alpha

Estrogen receptor beta Isoform of the estrogen receptor that has notable expression in the ovaries, prostate and cardiovascular system with actions frequently opposite to the alpha isoform.

Also: ER-beta · estrogen receptor beta · estrogen receptor beta

Glucocorticoid receptor Cytoplasmic nuclear receptor that, upon binding to its specific ligand, translocates to the cell nucleus to transactivate or transrepress metabolic and immune target genes.

Also: GR · cortisol receptor · glucocorticoid receptor

Follicle-stimulating hormone receptor G protein-coupled transmembrane receptor selectively expressed in Sertoli cells and granulosa cells that stimulates spermatogenesis and folliculogenesis.

Also: FSHR · FSH receptor · follicle-stimulating hormone receptor

Luteinizing hormone receptor Membrane G protein-coupled receptor expressed in Leydig and theca interna cells that transduces the signal for androgen synthesis and ovulation induction.

Also: LHR · LH receptor · luteinizing hormone receptor

Insulin receptor Tetrameric transmembrane glycoprotein with intrinsic tyrosine kinase activity that mediates the anabolic effects of insulin after its specific binding on the cell surface.

Also: insulin receptor · insulin receptor

LDL receptor Membrane glycoprotein responsible for ligand-mediated endocytosis of LDL particles, critically regulating plasma cholesterol concentrations.

Also: LDLR · low-density lipoprotein receptor · LDL receptor

Mineralocorticoid receptor High affinity nuclear receptor expressed in target epithelial tissues that regulates the expression of sodium channels and ion pumps in response to active mineralocorticoids.

Also: MR · aldosterone receptor · mineralocorticoid receptor

Tyrosine kinase receptor Transmembrane receptor with intrinsic enzymatic activity that catalyzes autophosphorylation on tyrosine residues after the binding of growth factors or specific peptide hormones.

Also: RTK · receptor tyrosine kinase · tyrosine kinase receptor

Vitamin D receptor Nuclear transcription receptor that mediates the effects of the active hormone calcitriol on calcium homeostasis, immune differentiation and bone remodeling.

Also: VDR · calcitriol receptor · vitamin D receptor · RVD · calcitriol receptor

Nuclear receiver Superfamily of transcription factors activated by lipophilic ligands that bind directly to DNA to modulate the expression of target genes.

Also: intracellular receptor · ligand-dependent transcription factor · nuclear receptor

Calcium sensing receptor G protein-coupled receptor expressed in parathyroid cells and renal tubules that detects minute variations in extracellular ionized calcium levels.

Also: CaSR · calcium-sensing receptor · parathyroid calcium sensor

Farnesoid X receptor Nuclear receptor activated by bile acids that critically regulates hepatic synthesis, transport and enterohepatic recirculation of bile salts.

Also: FXR · bile acid receptor · farnesoid X receiver

Liver X receptor Nuclear transcription receptor activated by oxysterols that acts as a key intracellular sensor of excess cholesterol and modulates its peripheral excretion.

Also: LXR · liver X receiver

Retinoid X receptor Nuclear receptor that forms heterodimers with multiple endocrine nuclear receptors, acting as a crucial integrator of metabolic and lipid signaling pathways.

Also: RXR · retinoid X receptor

Downregulation Cellular adaptive process by which the number of active receptors on the membrane decreases in response to chronic or excessive exposure to its corresponding ligand.

Also: down-regulation · receptor desensitization · receiver internalization

Upregulation Increase in the number or sensitivity of cellular receptors for a hormone or neurotransmitter in response to a persistently low concentration of said ligand.

Also: up-regulation · hypersensitization of receptors · recruitment of receivers

Renin Proteolytic enzyme secreted by the juxtaglomerular cells of the kidney that catalyzes the conversion of angiotensinogen into angiotensin I, initiating the vasoactive cascade of the renin-angiotensin-aldosterone system.

Also: angiotensinogenase · renin

Resistance to thyroid hormones Autosomal dominant hereditary syndrome characterized by mutations in the beta nuclear thyroid hormone receptors, reducing the cellular response to these hormones and raising their serum levels in a compensatory manner.

Also: Refetoff syndrome · insensitivity to thyroid hormones · thyroid hormone resistance

Leptin resistance Physiopathological state of obese individuals where the hypothalamus does not respond adequately to high concentrations of circulating serum leptin, losing its anorexigenic signal.

Also: leptin insensitivity · leptin resistance

Hormonal resistance Condition in which target tissues show a decreased or no response to normal or elevated circulating concentrations of a specific hormone due to defects in its receptors or signaling pathways.

Also: hormonal insensitivity · hormonal refractoriness · hormone resistance

Negative feedback Physiological mechanism of homeostatic control where the increase in a final product inhibits its own synthesis or secretion by acting on higher control centers.

Also: negative feedback · inhibition by product · negative backtest

Positive feedback Uncommon endocrine process where the accumulation of a hormone or physiological response stimulates even greater secretion, amplifying the initial stimulus as occurs in the peak of luteinizing hormone.

Also: positive feedback · positive feedback control · amplification loop

Circadian rhythm Endocrine and metabolic biological oscillation with a periodicity of approximately twenty-four hours, synchronized mainly by the suprachiasmatic nucleus and the light and dark cycle.

Also: nictemeral rhythm · daily oscillation · diurnal rhythm

Infradian rhythm Biological fluctuation that is repeated at intervals greater than twenty-four hours, as occurs representatively in the monthly ovarian cycle.

Also: seasonal rhythm · long cycle oscillation · infradian rhythm

Ultradian rhythm Pattern of biological activity or secretion with a periodicity of less than twenty-four hours, occurring in multiple cycles throughout the day.

Also: rapid oscillation · ultradian rhythm

Pulsatile secretion Hormonal release pattern characterized by episodic and intermittent discharges rather than continuous secretion, vital to avoid desensitization of target receptors.

Also: episodic release · pulse secretion · pulsatile secretion

Secretin Peptide hormone secreted by the S cells of the duodenum in response to acidic chyme that stimulates pancreatic secretion rich in water and bicarbonate.

Also: duodenal secretin · secretin

Estrogen receptor selectors Compound drugs that act selectively as estrogen agonists or antagonists depending on the tissue and type of receptor expressed locally.

Also: SERM · selective estrogen receptor modulators · selective estrogen receptor modulators

Carcinoid syndrome Systemic endocrine manifestation due to tumor secretion of serotonin and other vasoactive substances by metastatic carcinoid tumors, characterized by facial flushing crisis, persistent diarrhea and right heart disease.

Also: Thorson-Biörck syndrome · carcinoid syndrome

Bardet-Biedl syndrome Complex hereditary ciliopathy characterized by progressive central obesity, degenerative retinal dystrophy, postaxial polydactyly, cognitive delay and gonadal dysfunction.

Also: BBS · Bardet-Biedl syndrome

Bartter syndrome Renal channelopathy characterized by molecular defects in the reabsorption of sodium chloride in the thick ascending branch of the loop of Henle, simulating the chronic use of loop diuretics.

Also: Bartter's syndrome · Bartter salt wasting nephropathy

Mitochondrial DNA depletion syndrome Heterogeneous group of childhood genetic disorders characterized by a drastic reduction in the number of copies of the mitochondrial genome in specific target tissues.

Also: MDDS · mitochondrial DNA depletion syndrome

Osmotic demyelination syndrome Severe demyelinating neurological damage caused by excessively rapid therapeutic correction of severe chronic hyponatremia.

Also: extrapontine myelinolysis · osmotic demyelination syndrome

Gitelman syndrome Autosomal recessive tubulopathy characterized by inactivating mutations in the sodium-chlorine cotransporter of the distal convoluted tubule, simulating the continued use of thiazide diuretics.

Also: hypokalemia with familial hypocalciuria · Gitelman's syndrome · Gitelman's magnesium-losing nephropathy

Gordon syndrome Hereditary tubulopathy characterized by arterial hypertension and hyperkalemia due to mutations that overactivate the sodium-chloride cotransporter of the distal convoluted tubule.

Also: pseudohypoaldosteronism type II · Gordon's syndrome

HAIR-AN syndrome Extreme subtype of insulin resistance characterized by the simultaneous clinical presence of severe hyperandrogenism, extreme insulin resistance and acanthosis nigricans.

Also: HAIR-AN syndrome

Hungry bone syndrome State of severe and persistent hypocalcemia that occurs acutely after successful parathyroidectomy in patients with long-standing severe hyperparathyroidism.

Also: hungry bone syndrome · postparathyroidectomy hypocalcemia

Hunter syndrome X-linked mucopolysaccharidosis type II due to iduronate-2-sulfatase deficiency that manifests with progressive joint stiffness, hepatosplenomegaly, and psychomotor retardation without corneal opacity.

Also: MPS II · mucopolysaccharidosis type II · Hunter's syndrome

Hurler syndrome Severe mucopolysaccharidosis type I caused by the absence of the enzyme alpha-L-iduronidase that clinically presents with marked skeletal deformities, corneal opacity and early multisystem involvement.

Also: MPS I-H · mucopolysaccharidosis type I-H · Hurler's syndrome

Androgen insensitivity syndrome X-linked recessive genetic disorder where mutations in the androgen receptor prevent normal virilization of target tissues in genotypically male individuals.

Also: testicular feminization · SIA · androgen insensitivity syndrome

IPEX syndrome Lethal autoimmune disorder linked to the X chromosome due to mutations in the FOXP3 gene, characterized by severe enteropathy, exfoliative dermatitis and multiple autoimmune endocrinopathies of neonatal onset.

Also: IPEX · immunodysregulation-polyendocrinopathy-X-linked enteropathy · IPEX syndrome

Kallmann syndrome Genetic disorder characterized by congenital hypogonadotropic hypogonadism associated with partial or complete loss of the sense of smell due to failure in the migration of GnRH-secreting neurons and the olfactory bulb.

Also: olfactogenital dysplasia · Kallmann syndrome · hypogonadism with anosmia · congenital GnRH deficiency with hyposmia

Kearns-Sayre syndrome Mitochondrial myopathy characterized by the classic triad of progressive external ophthalmoplegia, pigmentary retinopathy and cardiac conduction blocks before the age of twenty.

Also: KSS · Kearns-Sayre syndrome

Klinefelter syndrome Chromosomal anomaly characterized by the presence of at least one supernumerary X chromosome in a male phenotype, leading to primary testicular insufficiency, gynecomastia and infertility.

Also: karyotype 47,XXY · XXY syndrome · Klinefelter syndrome

Empty sella syndrome Anatomical or radiological finding characterized by herniation of the subarachnoid space towards the interior of the sella turcica, flattening the pituitary gland against the bony walls.

Also: empty Turkish chair · empty sella syndrome

Leigh syndrome Subacute necrotizing encephalopathy of mitochondrial or autosomal inheritance characterized by symmetric lesions in the basal ganglia and progressive brainstem dysfunction.

Also: Leigh's disease · Leigh syndrome

Liddle syndrome Autosomal dominant disorder of renal epithelial sodium channels that causes constitutive activation of sodium reabsorption, resulting in severe hypokalemic hypertension.

Also: familial pseudohyperaldosteronism type I · Liddle's syndrome · primary pseudoaldosteronism type Liddle

Marine-Lenhart syndrome Uncommon coexistence in the same thyroid gland of autoimmune Graves' disease and one or more autonomous hyperfunctional thyroid nodules.

Also: Marine-Lenhart syndrome

Mauriac syndrome Uncommon complication of poorly controlled type 1 diabetes mellitus in children that associates severe glucogenic hepatomegaly, growth retardation and delayed puberty.

Also: hepatomegalic diabetic dwarfism · Mauriac syndrome

McCune-Albright syndrome Sporadic disorder due to a somatic activating mutation of the Gs alpha protein characterized by the triad of polyostotic fibrous dysplasia, café au lait spots, and hyperfunctional endocrinopathies.

Also: hyperfunctioning polyostotic fibrous dysplasia · McCune-Albright syndrome

MELAS syndrome Multisystem mitochondrial encephalomyopathy clinically characterized by recurrent stroke-like episodes, lactic acidosis, and muscle weakness.

Also: MELAS · mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes

MERRF syndrome Mitochondrial neurodegenerative disorder characterized by progressive myoclonic epilepsy, histological presence of torn red fibers in muscle biopsy and ataxia.

Also: MERRF · myoclonic epilepsy with ragged red fibers

Nelson syndrome Development of an aggressive corticotropin-secreting pituitary macroadenoma associated with skin hyperpigmentation after performing a therapeutic bilateral adrenalectomy.

Also: post-adrenalectomy pituitary tumor · Nelson's syndrome

Noonan syndrome Autosomal dominant multisystem disorder of the RAS-MAPK signaling pathway that shares phenotypic characteristics with Turner syndrome but presents with a normal karyotype and right heart involvement.

Also: pseudoturner syndrome · Noonan syndrome

Polycystic ovary syndrome Heterogeneous and common endocrine-metabolic disorder in women of reproductive age clinically characterized by chronic anovulation, clinical or biochemical hyperandrogenism and polycystic ovarian morphology.

Also: SOP · Stein-Leventhal syndrome · polycystic ovary syndrome

Prader-Willi syndrome Neurobehavioral and developmental genetic disorder due to the loss of expression of genes on paternal chromosome 15, characterized by neonatal hypotonia and subsequent development of obsessive hyperphagia.

Also: PWS · Prader-Labhart-Willi syndrome · Prader-Willi syndrome

Familial chylomicronemia syndrome Severe genetic disorder characterized by deficiency in lipoprotein lipase activity that causes a massive accumulation of chylomicrons and recurrent abdominal pain.

Also: SQF · classical chylomicronemia · familial chylomicronemia syndrome

Insulin resistance syndrome type A Rare endocrinopathy characterized by extreme insulin resistance in young non-obese women associated with severe acanthosis nigricans and hyperandrogenism due to mutations in the insulin receptor.

Also: insulin resistance type A · type A insulin resistance syndrome

Schmidt syndrome Polyglandular autoimmune endocrinopathy characterized by the simultaneous presence of autoimmune adrenal insufficiency and chronic autoimmune thyroiditis.

Also: autoimmune polyglandular syndrome type II · Schmidt's syndrome

Sheehan syndrome Ischemic necrosis of the pituitary gland due to severe obstetric hemorrhage and cardiovascular collapse during or immediately after childbirth.

Also: postpartum panhypopituitarism · puerperal pituitary necrosis · Sheehan's syndrome · ischemic postpartum panhypopituitarism · obstetric adenohypophysis infarction

Swyer syndrome Pure gonadal dysgenesis characterized by a normal male karyotype associated with the absence of testicular development and the presence of immature phenotypic female internal and external genitalia.

Also: pure gonadal dysgenesis 46,XY · Swyer syndrome

Williams-Beuren syndrome Developmental disorder due to a chromosomal microdeletion characterized by supravalvular aortic stenosis, pixie facies, extremely friendly personality, and idiopathic neonatal hypercalcemia.

Also: Williams syndrome · Williams-Beuren syndrome

Wolfram Syndrome Recessive neurodegenerative genetic disorder characterized clinically by the association of type 1 diabetes mellitus, progressive optic atrophy, central diabetes insipidus and sensorineural deafness.

Also: DIDMOAD syndrome · Wolfram syndrome

Zellweger syndrome Fatal multisystem disorder characterized by the absence of functional peroxisomes due to mutations in peroxisomal biogenesis genes that produces craniofacial and neurological anomalies and adrenal insufficiency.

Also: cerebro-hepato-renal syndrome · Zellweger syndrome

Zollinger-Ellison syndrome Clinical entity characterized by gastrin hypersecretion of tumor origin that leads to persistent hyperproduction of gastric acid and the development of recurrent and severe peptic ulcers.

Also: gastrinoma · Zollinger-Ellison syndrome

Sick euthyroid syndrome Transient, non-thyroidal alteration of thyroid function tests that occurs in patients with critical systemic diseases not related to the thyroid axis itself.

Also: non-thyroid disease syndrome · low T3 · euthyroid sick syndrome

Autoimmune polyglandular syndrome type 1 Autoimmune disorder due to mutations in the AIRE gene that is clinically manifested by the classic triad of chronic mucocutaneous candidiasis, autoimmune hypoparathyroidism and adrenal insufficiency.

Also: APECED · Whitaker syndrome · autoimmune polyglandular syndrome type 1

Autoimmune polyglandular syndrome type 2 Multigenic disorder characterized by the mandatory presence of primary adrenal insufficiency associated with autoimmune thyroiditis or autoimmune diabetes mellitus.

Also: broad-spectrum Schmidt syndrome · autoimmune polyglandular syndrome type 2

Somatopause Physiological and progressive decrease in the daily secretion of growth hormone and insulin-like growth factor type 1 directly related to the aging process.

Also: somatopause

Somatostatin Inhibitory tetradecapeptide produced in the hypothalamus and pancreas that suppresses the secretion of growth hormone, thyrotropin and insulin.

Also: GHIH · growth hormone-inhibiting hormone · somatostatin

Somatostatinoma Extremely rare neuroendocrine neoplasia secreting somatostatin that alters bile transit and inhibits the secretion of digestive enzymes and hormones, causing cholelithiasis, steatorrhea and moderate diabetes.

Also: somatostatin-secreting tumor · somatostatinoma

Somatotropin Peptide hormone secreted by the somatotroph cells of the anterior pituitary that promotes somatic growth and anabolic metabolism by stimulating somatomedins in the liver.

Also: GH · growth hormone · somatotropin

Insulin receptor substrate Key adapter protein that is phosphorylated on multiple tyrosine residues by the activated insulin receptor, initiating the intracellular signaling cascades of glucose metabolism.

Also: IRS-1 · insulin receptor substrate 1 · insulin receptor substrate 1

Tecoma Benign stromal tumor of the ovary made up of vacuolated theca cells filled with lipids with the capacity to actively produce estrogens.

Also: theca cell tumor · thecoma · estrogenic ovarian thecoma

White adipose tissue Major fatty deposit in the body whose main function is the storage of energy in the form of triglycerides and the secretion of regulatory adipokines.

Also: white fat · WAT · white adipose tissue

Brown adipose tissue Richly vascularized and innervated adipose tissue that is characterized by having numerous mitochondria with uncoupling protein 1 destined for the direct production of heat.

Also: brown fat · BAT · brown adipose tissue

Thelarche Appearance and initial development of breast tissue in girls, a phenomenon that usually constitutes the first visible sign of normal pubertal maturation.

Also: telarche

Carboxy-terminal telopeptide of type I collagen Peptide fragment released into the bloodstream during the process of resorption and degradation of type I collagen in bone by osteoclasts.

Also: CTX · beta-CTX · C-terminal telopeptide of type I collagen

Adaptive thermogenesis Physiologically regulated heat production in brown adipose tissue in response to environmental stimuli such as cold exposure or dietary intake.

Also: thermogenesis without shivering · adaptive thermogenesis

Testosterone Main androgenic hormone synthesized by the Leydig cells of the testicles, responsible for the development of male secondary sexual characteristics and tissue anabolic effects.

Also: free testosterone · testosterone

Thyroglobulin Large glycoprotein synthesized exclusively by thyrocytes, which serves as a structural scaffold for the iodination and intrafollicular storage of thyroid hormones.

Also: Tg · thyroglobulin

Hashimoto's thyroiditis Chronic autoimmune inflammatory disease of the thyroid gland, histologically characterized by progressive lymphocytic infiltration and tissue destruction mediated by peroxidase antibodies.

Also: chronic lymphocytic thyroiditis · Hashimoto's thyroiditis

De Quervain's thyroiditis Painful subacute inflammation of the thyroid, presumably of viral etiology, characterized by cervical pain radiating to the jaw, fever, elevation of acute phase reactants and transient thyrotoxicosis.

Also: subacute granulomatous thyroiditis · De Quervain's thyroiditis · de Quervain's thyroiditis

Riedel's thyroiditis Extremely rare variant of chronic thyroiditis characterized by fibrous and invasive replacement of the thyroid parenchyma that extends into adjacent cervical anatomical structures.

Also: invasive fibrous thyroiditis · Riedel's thyroiditis

Amiodarone-induced thyroiditis Destructive or hyperfunctional thyroid dysfunction caused by the high iodine content and direct toxicity of the antiarrhythmic drug amiodarone on thyrocytes.

Also: thyroid dysfunction due to amiodarone · amiodarone-induced thyroiditis

Interferon-induced thyroiditis Autoimmune thyroid inflammation and dysfunction triggered by systemic therapy with interferon alfa, frequently manifested with hyperthyroidism followed by hypothyroidism.

Also: interferon thyroiditis · interferon-induced thyroiditis

Lithium-induced thyroiditis Chronic inflammation or goiter of pharmacological origin secondary to prolonged use of lithium carbonate, which directly interferes with the synthesis and release of thyroid hormones.

Also: lithium goiter · lithium-induced thyroiditis

Acute infectious thyroiditis Acute bacterial suppurative process of the thyroid gland, typically facilitated by the persistence of a pyriform sinus fistula in childhood.

Also: suppurative thyroiditis · acute infectious thyroiditis

Postpartum thyroiditis Transient autoimmune thyroid dysfunction that occurs within the first year after childbirth, characterized by an initial phase of thyrotoxicosis followed by hypothyroidism.

Also: puerperium thyroiditis · postpartum thyroiditis

Silent thyroiditis Transient autoimmune inflammatory disorder of the thyroid that presents clinically with painless thyrotoxicosis followed by temporary hypothyroidism, without presenting goiter that is painful to the touch.

Also: subacute lymphocytic thyroiditis · painless thyroiditis · silent thyroiditis

Tyrosinemia type 1 Severe metabolic disorder caused by deficiency of the enzyme fumarylacetoacetate hydrolase that leads to progressive hepatorenal damage and early liver failure.

Also: hepatorenal tyrosinemia · tyrosinemia type 1

Tyrosinemia type 2 Autosomal recessive disorder caused by tyrosine aminotransferase deficiency that manifests with painful ocular lesions, palmoplantar hyperkeratosis, and delayed neurological development.

Also: Richner-Hanhart syndrome · oculocutaneous tyrosinemia · tyrosinemia type 2

Tyrosinemia type 3 Very rare metabolic defect caused by a deficiency of the enzyme 4-hydroxyphenylpyruvate dioxygenase characterized by psychomotor retardation and seizures without liver or skin involvement.

Also: tyrosinemia type III · tyrosinemia type 3

Glucose transporter type 1 Constitutively expressed glucose facilitating transporter glycoprotein that provides the basal entry of carbohydrates into the blood-brain barrier and erythrocytes.

Also: GLUT1 · facilitated glucose transporter 1 · glucose transporter type 1

Glucose transporter type 2 High-capacity, bidirectional glucose transporter present in pancreatic beta cells, hepatocytes and renal tubules that acts as a metabolic glucose sensor.

Also: GLUT2 · glucose transporter 2 · glucose transporter type 2

Glucose transporter type 3 High affinity glucose transporter expressed selectively and dominantly in the neurons of the central nervous system to ensure constant metabolic supply.

Also: GLUT3 · glucose transporter 3 · glucose transporter type 3

Glucose transporter type 4 Insulin-regulated glucose transporter isoform that translocates from intracellular vesicles to the membrane in response to insulin activation in muscle and adipose tissue.

Also: GLUT4 · insulin-sensitive glucose transporter · glucose transporter type 4

Sodium-glucose transporter type 1 Sodium-dependent cotransport protein involved in the apical absorption of glucose and galactose in the brush border of the intestinal enterocyte and to a lesser extent in the kidney.

Also: SGLT1 · intestinal sodium-glucose cotransporter · sodium-glucose cotransporter 1

Sodium-glucose transporter type 2 Secondary active transport cotransporter located in the renal proximal convoluted tubule responsible for the reabsorption of the largest proportion of filtered glucose.

Also: SGLT2 · sodium-glucose cotransporter 2 · sodium-glucose cotransporter 2

Triptorelin Long-acting agonist analog of the gonadotropin-releasing hormone receptor used for reversible chemical castration in advanced prostatic neoplasms.

Also: triptorelin

Triiodothyronine Biologically active thyroid hormone formed dominantly by the peripheral deiodination of thyroxine that stimulates basal cellular metabolism.

Also: triiodothyronine

Reverse triiodothyronine Biologically inactive isomer of triiodothyronine produced through the specific deiodination of the inner ring of thyroxine by type 3 deiodinase.

Also: rT3 · reverse T3 · reverse triiodothyronine

Sertoli-Leydig cell tumor Uncommon stromal ovarian neoplasia that actively secretes testosterone and other androgens, causing rapid virilization and defeminization in young women.

Also: arrenoblastoma · androblastoma · Sertoli-Leydig cell tumor

Pentose phosphate pathway Alternative metabolic pathway of glucose oxidation that produces ribose-5-phosphate for the synthesis of nucleotides and reducing phosphate equivalents of nicotinamide adenine dinucleotide.

Also: phosphogluconate pathway · pentose shunt · pentose phosphate pathway

Vipoma Extremely rare neuroendocrine tumor that secretes vasoactive intestinal peptide, causing a condition characterized by massive watery diarrhea, extreme hypokalemia and achlorhydria.

Also: Verner-Morrison syndrome · VIPoma

Iodotyrosine deiodinase Intracellular enzyme responsible for the deiodination and recovery of free iodine from monoiodotyrosine and diiodotyrosine molecules remaining from the proteolysis of thyroglobulin.

Also: DEHAL1 · iodotyrosine deiodinase

Endocrine and metabolic

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