Effect of phenobarbital upon serum cholesterol lipoprotein fractions of three rodent species.

Phenobarbital (PB) in doses previously shown to be optimal for induction of hepatic microsomal enzymes had no effect on the cholesterol content of whole serum or of serum lipoprotein fractions in the guinea pig, but reduced high density lipoprotein cholesterol (with increase in very low density lipoprotein cholesterol) in the rabbit, and increased high density lipoprotein cholesterol (as well as total and low density lipoprotein cholesterol) in the rat. These results, when taken together with previous data demonstrating that PB increases serum triglyceride in the rabbit but lowers it in the rat, suggest that the drug may be atherogenic in the rabbit but not in the rat which, in any case, is highly resistant to atheroma.