title: Effects of dexamethasone 17-esters on adrenal weight and hydrolysis of glucocorticoid 17-esters in rat fetuses.
abstract: Prednisolone was detected in the brain of rat fetus subcutaneously administered prednisolone 17-acetate. After the subcutaneous injection of betamethasone 17-propionate or dexamethasone 17-propionate to rat fetus, the unchanged steroid was detected mainly in the brain. The hydrolytic rates of prednisolone 17-acetate, betamethasone 17-esters (acetate, propionate) and dexamethasone 17-esters (acetate, propionate, valerate) in the livers of rat fetuses were studied. Prednisolone 17-acetate was hydrolyzed to prednisolone very rapidly. Betamethasone 17-esters and dexamethasone 17-esters were hydrolyzed more slowly. The hydrolytic rate of dexamethasone acetate among the dexamethasone 17-esters was the most rapid, followed by propionate and valerate. The adrenals of rat fetuses became significantly atrophied after subcutaneous administration of dexamethasone and its 17-esters. The simultaneous administration of betamethasone 17, 21-dipropionate and its metabolite betamethasone impaired the hypertrophic effect of the former on the adrenal weights of rat fetuses. The effects of the hydrolytic rate of these glucocorticoid 17-esters and of C16-methyl conformation on the hypothalamo-pituitary-adrenal system in rat fetuses are discussed.
mesh_terms: D000311:Adrenal Glands / Q000187:drug effects*; D000818:Animals; D001623:Betamethasone / Q000031:analogs & derivatives / Q000494:pharmacology; D001921:Brain / Q000378:metabolism; D003907:Dexamethasone / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D005333:Fetus / Q000187:drug effects* / Q000378:metabolism; D006868:Hydrolysis; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects; D008099:Liver / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D010913:Pituitary-Adrenal System / Q000187:drug effects; D011247:Pregnancy; D051381:Rats
chemical_list: D003907:Dexamethasone; D001623:Betamethasone