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

This study was conducted to investigate the effects of effects of enprostil, a prostaglandin $E_2$, analogue, on liver triacylglycerol content and factors that regulate liver lipid metabolism in mice. Mice received vehicle or $10{\mu}g$ 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 ${\beta}$-oxidation activity was inconsistent with the result of liver triacylglycerol content, because its activity was lovered by enprosil. In another experiment, the effect of enprostil on lipid metabolism in mice was investigated in a short period. Mice received $10{\mu}g$ 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 carnitine palmitoyltransferase and peroxisomal ${\beta}$-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 result from the decreased entry of free fatty acid into liver.