Effect of clofibric acid administration on palmitoyl-CoA hydrolase activity in rat liver

The activity of palmitoyl-CoA hydrolase (EC 3.1.2.2.) in the liver from clofibric acid (p-chlorophenoxyisobutyric acid)-treated rats was studied. The study for subcellular localization showed that palmitoyl-CoA hydrolase was found in both cytosolic and microsomal fractions. Feeding of diet containing 0.5% clofibric acid for 6 days, the specific activities of palmitoyl-CoA hydrolase in homogenates, microsomes and cytosol were increased 5, 2 and 22 times, respectively, compared with that in control rats. Gel filtration of cytosolic fraction showed two new peaks, which have the activity capable of hydrolyzing palmitoyl-CoA and different molecular weights compared with the peaks in cytosol of control rat liver. Acyl-CoA hydrolases in cytosolic fraction showed different kinetic properties with each other.