title: Relation of the pituitary gland to gonadal hormone effects on the adrenocortical 11beta-hydroxylase system in rats.
abstract: Studies were conducted to further examine the mechanisms responsible for gonadal hormone effects on the rat adrenocortical 11beta-hydroxylase system. Despite higher concentrations of cytochrome P-450 and larger 11-deoxycorticosterone (DOC)-induced difference spectra in adrenal mitochondria from females than males, no sex difference in 11beta-hydroxylase activity was observed. The pregnenolone-induced difference spectrum, indicative of cholesterol binding to cytochrome P-450, also was similar in males and females. Testosterone administration to castrated males lowered both 11beta-hydroxylase activity and mitochondrial cytochrome P-450 content. Estradiol produced the opposite effects in castrated females. However, when given to ACTH-replaced hypophysectomized rats, neither testosterone nor estradiol affected cytochrome P-450 levels or the rate of 11beta-hydroxylation. These observations, taken with the known effects of estradiol and testosterone on ACTH secretion in rats and the effects of ACTH on 11beta-hydroxylation, indicate that gonadal hormone effects on the 11beta-hydroxylase system are mediated by ACTH.
mesh_terms: D000311:Adrenal Glands / Q000201:enzymology*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D002369:Castration; D003345:Corticosterone / Q000031:analogs & derivatives; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007016:Hypophysectomy; D008297:Male; D008928:Mitochondria / Q000201:enzymology; D009929:Organ Size; D010053:Ovary / Q000502:physiology; D011284:Pregnenolone; D051381:Rats; D013053:Spectrophotometry; D013250:Steroid Hydroxylases / Q000378:metabolism*; D013737:Testis / Q000502:physiology; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D013739:Testosterone; D004958:Estradiol; D011284:Pregnenolone; D000324:Adrenocorticotropic Hormone; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D003345:Corticosterone