Effects of Prostaglandin E₂ Analogue, Enprostil, on Lipid Metabolism in Mice

This study was conducted to investigate the effects of enprostil, a prostaglandin E₂ analogue, on liver triacylglycerol content and factors that regulate liver lipid metabolism in mice. Mice received vehicle or 10 μg enprostil/kg body weight intraperitoneally every 6 h, and were killed at 0, 6, 12, 18 and 24 h after the first injection. Enprostil significantly lowered liver triacylglycerol content after 12 h of the first injection. However, the peroxisomal β-oxidation activity was inconsistent with the result of liver triacylglycerol content, because its activity was lowered by enprostil. In another experiment, the effect of enprostil on lipid metabolism in mice was investigated in a short period. Mice received 10 μg enprostil/kg body weight intraperitoneally, and were killed after 0, 5, 10, 30 and 60 min. After 30 min, malic enzyme activity was significantly increased by the administration of enprostil compared with the activity at 5 min after. No significant changes in liver camitine palmitoyltransferase and peroxisomal β-oxidation activities were observed. Plasma free fatty acid concentrations were markedly reduced from 5 through 60 min after the administration of enprostil. Consequently, enprostil suppressive effect on liver triacylglycerol concentration might resut from the decreased entry of free fatty acid into the liver.