title: Effects of interferon-inducing agents on hepatic cytochrome P-450 drug metabolizing systems.
abstract: Duration and intensity of drug action are greatly influenced by the rates of which drugs are biotransformed by the cytochrome P-450-linked monooxygenase systems of the hepatic endoplasmic reticulum. Several interferon-inducing agents (poly rI.rC, tilorone, vaccines, viruses, endotoxin) are shown to markedly depress hepatic P-450 systems when administered to rodents. The interferon (IF) inducers that depress hepatic drug metabolism also modulate certain immune responses; it is therefore not known whether the depression of P-450 is due to IF per se or to the action of IF-inducing agents on one or more components of the immune system. The loss of cytochrome P-450 elicited by IF-inducing agents is accompanied by a perturbation of heme metabolism associated with the dissociation of heme from cytochrome P-450. The agents also cause losses of hepatic catalase and tryptophan 2,3-dioxygenase. These studies predict that viral infections, vaccinations, and treatment with IF-inducing agents will be shown to seriously impair the metabolism of drugs in humans.
mesh_terms: D000818:Animals; D002374:Catalase / Q000037:antagonists & inhibitors; D002478:Cells, Cultured; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D006418:Heme / Q000378:metabolism; D066298:In Vitro Techniques; D007369:Interferon Inducers / Q000494:pharmacology*; D007700:Kinetics; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D011070:Poly I-C / Q000494:pharmacology; D051381:Rats; D013994:Tilorone / Q000494:pharmacology; D014366:Tryptophan Oxygenase / Q000037:antagonists & inhibitors
chemical_list: D007369:Interferon Inducers; D006418:Heme; D003577:Cytochrome P-450 Enzyme System; D002374:Catalase; D014366:Tryptophan Oxygenase; D013994:Tilorone; D011070:Poly I-C