Stimulation of cholesterol 7 -hydroxylase by phenobarbital in two strains of rats.
The effect of phenobarbital administration on the in vitro activity of cholesterol 7alpha-hydroxylase was investigated in two strains of rats. In rats of the Wistar strain the daily injection of phenobarbital (100 mg/kg per day ip for 5 days) produced a 33% increase in hepatic microsomal protein and a sixfold stimulation of specific activity of the enzyme. In rats of the Charles River colony (Sprague-Dawley derived) identical treatment with phenobarbital resulted in a 45% increase in hepatic microsomal protein and no change in the specific activity of cholesterol 7alpha-hydroxylase. Plasma phenobarbital concentrations were three to four times greater in the Wistar rats, suggesting that these strains differ also in their capacity to metabolize phenobarbital.
D000818:Animals; D002247:Carbon Isotopes; D002784:Cholesterol; D002855:Chromatography, Thin Layer; D004790:Enzyme Induction; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000096:biosynthesis* / Q000097:blood; D010634:Phenobarbital / Q000097:blood / Q000494:pharmacology*; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity
D002247:Carbon Isotopes; D002784:Cholesterol; D006899:Mixed Function Oxygenases; D010634:Phenobarbital