Bezafibrate reduces mRNA levels of adipocyte markers and increases fatty acid oxidation in primary culture of adipocytes. Diabetes 2001;50:1883

The molecular mechanisms by which peroxisome prolif-erator–activated receptor (PPAR) activation by fibrates reduces fat deposition and improves insulin sensitivity are not completely understood. We report that expo-sure of a rat primary culture of adipocytes for 24 h to the PPAR activator bezafibrate increased the mRNA levels of crucial genes involved in peroxisomal and mitochondrial b-oxidation. The mRNA levels of the peroxisomal b-oxidation rate-limiting enzyme acyl-CoA oxidase and of the muscle-type carnitine palmitoyl transferase I (M-CPT-I), which determines the flux of mitochondrial b-oxidation, increased by 1.6-fold (P < 0.02) and 4.5-fold (P 5 0.001), respectively. These changes were accompanied by an increase in the tran-script levels of the uncoupling protein-2 (UCP-2; 1.5