Effects of ethyl-p-chlorophenoxyisobutyrate, clofibrate, on the plasma and red blood cell free fatty acids of the rat

By using modifications of the Dole free fatty acid (FFA) extraction procedure, the present study demonstrated that ethyl-p-chlorophenoxyisobutyrate (Clofibrate or Atromid-S) given orally and intraperitoneally to rats at doses of 50, 100 and 800 mg/kg/day for 9–30 days produced 40–80 % decreases in the levels of plasma and red blood cell FFA. Near maximum FFA-lowering effects were obtained with the lower doses. These observations support the concept that some of the clofibrate-induced reductions in the circulating levels of cholesterol, phospholipids, and triglycerides are due to a reduction in FFA availability. Besides decreasing the circulating levels of FFA, Clofibrate treatment resulted in certain alterations in the relative composition of the plasma FFA. In particular, there was an increase in the relative content of plasma oleic acid, from 12 % of the total plasma in untreated rats to about 22 % in treated animals (100 mg/kg/day, i.p., for 24 days), and a decrease in the linoleic acid content, from about 9 % in untreated to 3 % in treated animals.