Increase in hepatic carnitine acetyltransferase activity associated with peroxisomal (microbody) proliferation induced by the hypolipidemic drugs clofibrate, nafenopin, and methyl clofenapate

A significant increase in hepatic carnitine acetyltransferase (CAT) was observed in male wild type and acatalasemic mice treated with the hypolipidemic compounds clofibrate, nafenopin and methyl clofenapate. The increased activity of this enzyme appeared to parallel the hepatic microbody (perisoxome) proliferation induced by these agents. Additional evidence for the association of peroxisome proliferation and enhanced CAT activity is derived from the observation that the CAT activity in male rats and male wild type mice treated with clofibrate was approximately 2 fold higher than that found in clofibrate treated females. This difference in CAT activity is presumably due to the fact that clofibrate causes microbody proliferation in males but not in females.