Proliferation of peroxisomes without simultaneous induction of the peroxisomal fatty acid beta-oxidation.

Marked proliferation of rat hepatic peroxisomes is observed after treatment with a new potent hypolipidemic drug BM 15766, as well as after bezafibrate. Whereas the relative specific activity of the peroxisomal fatty acid beta-oxidation system is not affected by BM 15766 it is significantly increased after bezafibrate. This is also confirmed by immunoblot analysis of individual beta-oxidation enzymes in highly purified peroxisome fractions. These observations suggest that peroxisome proliferation and the induction of the fatty acid beta-oxidation are regulated separately.