Metyrapone

**Semantic type:** Pharmacologic Substance

**Definition:** A pyridine derivative and a glucocorticoid synthesis inhibitor. Metyrapone inhibits 11-beta-hydroxylase, thereby inhibiting synthesis of cortisol from 11-deoxycortisol and corticosterone from desoxycorticosterone in the adrenal gland. Removal of the negative feedback mechanism exerted by cortisol results in increased adrenocorticotropic hormone (ACTH) secretion by the pituitary gland. In turn, continuing stimulation of adrenal gland by ACTH results in accumulation of corticoid precursors, 11-desoxycortisol and desoxycorticosterone. These metabolites are excreted in urine that maybe used as indicators for pituitary responsiveness.

**Synonyms:** - 1-Propanone, 2-methyl-1,2-di-3-pyridinyl- - 2-Methyl-1,2-di-3-pyridinyl-1-propanone - METYRAPONE - Metopirone