EFFECTS OF DIETARY-TREATMENT WITH 11 DICARBOXYLIC-ACIDS, DIETHYLCARBOXYLIC ESTERS AND FATTY-ACIDS ON PEROXISOMAL FATTY-ACID BETA-OXIDATION, EPOXIDE HYDROLASES AND LAURIC ACID OMEGA-HYDROXYLATION IN MOUSE-LIVER

C57B1/6 male mice were exposed through their diet to 11 dicarboxylic acids, carboxylic acids and diethyldicarboxylesters for 10 days. For the diacids and diethylesters this treatment resulted in a chain length-dependent induction of lauryl-CoA oxidase and cyanide-insensitive palmitoyl-CoA oxidation activities. A chain length of 12 carbon atoms or more seemed to be necessary for induction of these two activities. In addition, the same chain length dependence was observed for induction of lauric acid omega+ omega- 1 hydroxylase activity and increase in the protein content of the mitochondrial fraction. Treatment with two "natural" fatty acids, i.e. lauric and palmitic acid gave no effect at all on these various parameters. In no case was induction of cytosolic and mitochondrial epoxide hydrolase activities observed. Instead, a slight decrease in these activities was observed after administration of diacids with a chain length of 4-8 carbon atoms, whereas microsomal epoxide hydrolase activity was concurrently induced.