The antiglucocorticoid RU486 inhibits the ethanol-induced increase of tryptophan oxygenase.
The effect of the glucocorticoid-antagonist RU486 (Roussel-Uclaf, France) on the increased activity of hepatic tryptophan oxygenase (TO) after administration of corticosterone and ethanol in rats was studied. RU486 (40 mg/kg per os) inhibited completely the effect of corticosterone (5-15 mg/kg injected intraperitoneally) on TO. Ethanol (4 g/kg) given intraperitoneally is followed by peak corticosterone concentrations comparable to those seen after the administration of 5-10 mg exogenous corticosterone, and increased the TO activity 3-fold 4 h after the injection. RU486 inhibited completely the ethanol-induced increase of TO, indicating that this increase is mediated by corticosterone.
D000818:Animals; D003345:Corticosterone / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004963:Estrenes / Q000494:pharmacology*; D000431:Ethanol / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D005938:Glucocorticoids / Q000037:antagonists & inhibitors* / Q000502:physiology; D008099:Liver / Q000378:metabolism*; D008297:Male; D015735:Mifepristone; D051381:Rats; D011919:Rats, Inbred Strains; D014366:Tryptophan Oxygenase / Q000378:metabolism*
D004963:Estrenes; D005938:Glucocorticoids; D015735:Mifepristone; D000431:Ethanol; D014366:Tryptophan Oxygenase; D003345:Corticosterone