EFFECTS OF UBIQUINONE AND MEVALONIC ACID ON HEPATIC PEROXISOMAL ENZYMES INDUCED BY DEHYDROEPIANDROSTERONE

The adrenal steroid, dehydroepiandrosterone (DHEA) has been identified as a peroxisome proliferator. We examined the effects of the cellular antioxidant ubiquinone and its precursor mevalonic acid on the induct ion of enzymes associated with DHEA-mediated peroxisome proliferation in male F-344 rats. Upon treatment with DHEA (300 mg/kg orally for 14 days), there was a significant increase in hepatic activities of perox isomal beta-oxidation (3 fold), 3-ketoacyl-CoA thiolase (4 fold) and c atalase (1.8 fold). Co-administration of either mevalonic acid (100 mg /kg intraperitoneally) or ubiquinone (50 mg/kg orally) with DHEA signi ficantly attenuated the DHEA-mediated induction of these enzymes. Howe ver, neither ubiquinone nor mevalonic acid alone significantly altered peroxisomal enzyme activities in rat liver. These data suggest that e xogenous administration of ubiquinone or mevalonic acid can modulate t he induction of the enzymes involved in peroxisome proliferation.