Genetic Variation of Drug–Metabolizing Enzymes in the Wistar Rat

Rats of the Wistar/Af/Han/Mol/(Han 67) strain were preselected for the inducibility of the hepatic soluble aldehyde dehydrogenase, after treatment with phenobarbital (80 mg/kg daily, intraperitoneally, for 4 days) and open liver biopsy. Animals with highly induced aldehyde dehydrogenase also had a 50 and 40 % difference in the induction of D–glucuronolactone dehydrogenase and NADPH–cytochrome c reductase respectively. Other enzymes of the hepatic drug hydrox–ylation and glucuronidation did not show significant variation in the induction pattern between the two genetic groups. After inbreeding, the second filial generation was used in order to determine enzyme activities without any pretreatment. The basal activities of aldehyde and D–glucuronolactone dehydrogenase, but not of NADPH–cytochrome c reductase, were also different in the untreated animals. Urinary excretion of D–glucaric acid was the same in the two groups, both in the basal and the induced state.