Effects of phenobarbital on digitoxin metabolism in guinea-pig liver slices.
1. [3H]Digitoxin was incubated for 2-5 h with liver slices from control and phenobarbital-pretreated guinea-pigs. Metabolites were the same in both groups. 2. After 5 h incubation, a 6-fold increase in unmetabolized digitoxin was found in the phenobarbital-pretreated group compared with controls. 3. The major metabolite extracted by chloroform is formed by hydroxylation at an unknown position of the cardenolide nucleus, which is not the 12 beta-hydroxy position. Only half the amount of this metabolite was formed in livers of pretreated animals, compared to controls, in 2 h, after 5 h incubation similar amounts occurred in both groups. 4. Water-soluble metabolites decreased 2-fold in phenobarbital-pretreated animals at 2 and 5 h of incubation.
D000818:Animals; D002855:Chromatography, Thin Layer; D004074:Digitoxin / Q000378:metabolism*; D006168:Guinea Pigs; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010634:Phenobarbital / Q000494:pharmacology*
D004074:Digitoxin; D010634:Phenobarbital