The effects of administering N-(2-benzoyloxyethyl) norfenfluramine to rats on the hepatic synthesis of glycerolipids.

N-(2-Benzoyloxyethyl) norfenfluramine (S-780) was administered to rats by stomach tube at a dose of 50 mg kg-1 of body weight. Livers of the rats which were given an acute dose of the drug synthesized more triacylglycerol, phosphatidylcholine and phosphatidylethanolamine from [1,3-3H]glycerol and [14C]palmitate than did those of control rats. The measurements were made by injecting a mixture of the radioactive precursors into the portal veins of anaesthetized rats and freeze clamping a portion of the liver 1 min later. Diffferent results were obtained after treating rats daily with S-780 for 5 days. Liver slices from these rats synthesized less triacylglycerol and relatively more phosphatidylinositol plus phosphatidylserine from [3H]glycerol than did those of control rats. S-780 treatment depressed the hepatic synthesis of phosphatidylcholine and phosphatidylethanolamine as measured in vivo after intrapotal injection of [14C]palmitate and [3H]glycerol. Chronic treatment with S-780 also depressed food intake and lowered liver weight and body weight of rats fed the 41B diet. The results are discussed in relation to the effects of S-780 on the synthesis of glycerolipids.