Induction of hepatic cytochrome P450 by phenobarbitone in rhesus monkey (Macaca mulatta)

An intraperitoneal administration of PB at a daily dose of 50 mg Kg-1 body wt for 4 days increased the specific content of hepatic microsomal heme, cytochrome P450 and the activity of aminopyrine N-demethylase by 1.8, 2.8 and 3.5 fold respectively. These results were substantiated by the intensification of the 52.5 KDa polypeptide in the electrophoretogram of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the hepatic microsomes obtained from PB-pretreated versus control macaques. PB did not affect the hepatic content of cytochrome b5 and the activity of NADPH cytochrome c reductase, whereas it decreased the activity of NADH cytochrome c reductase in the rhesus monkeys. To the best of our knowledge this is a first report on the induction of hepatic cytochrome P450 and related enzymes by PB in rhesus monkeys.