Induction of hepatic gamma-glutamyl transpeptidase in rats by repeated administration of aminopyrine.
The effect of a 20-day administration of aminopyrine (600 mg kg-1) as well as two metabolites of aminopyrine, 4-aminoantipyrine (525 mg kg-1) and 4-acetamidoantipyrine (635 mg kg-1), on several hepatic, kidney and serum enzyme activities were investigated. In the aminopyrine-treated group, a pronounced induction of gamma-glutamyl transpeptidase was shown in the whole homogenate as compared to that in the hepatic microsomes. Serum gamma-glutamyl transpeptidase activity was also increased by administration of aminopyrine or 4-aminoantipyrine. No change in gamma-glutamyl transpeptidase activity was observed in kidney and hepatic cytosolic fractions. In all cases, 4-acetamidoantipyrine treatment showed no significant change in the enzyme activities tested. Under the same experimental condition, the amounts of cytochrome P-450 and b5, the activities of aminopyrine N-demethylase, aniline hydroxylase and carboxylesterase of liver microsomes were all induced in the aminopyrine- and 4-aminoantipyrine-treated rats. The activities of NADPH cytochrome c reductase and NADH ferricyanide reductase were also increased. The results in this paper support the view that repeated administration of aminopyrine induces hepatic membrane-bound enzyme, particularly, gamma-glutamyl transpeptidase activity.
D000632:Aminopyrine / Q000494:pharmacology*; D000675:Ampyrone / Q000494:pharmacology; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D004798:Enzymes / Q000097:blood; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D005723:gamma-Glutamyltransferase / Q000096:biosynthesis*
D004798:Enzymes; D000632:Aminopyrine; D000675:Ampyrone; D005723:gamma-Glutamyltransferase