Hepatic origin of triglycerides in fatty livers produced by the continuous intragastric infusion of an ethanol diet

Male Wistar rats were maintained for 30 days on an independent and continuous intragastric infusion of ethanol and nutritionally defined liquid diet containing only a small amount of corn oil (CO-4.9% calories). Ethanol intake was progressively increased from 32% to 40.4% of the total calories to maintain a high degree of intoxication during this period. Rats in the control group were infused with an isocaloric diet in which alcohol was replaced by dextrose. The liver triglyceride (TG) content of rats given alcohol (61.5±16.4 mg/g) was ca. 10-fold greater than that of controls (5.9±2.1 mg/g) and similar to that observed previously in rats fed an ethanol diet containing high levels of fat (35% and 43% calories). In TG of fatty liver, the level of 18∶2 was small (3%), even though CO in the diet contained a high level of this acid. Furthermore, 16∶1 and 16∶0 contents were markedly elevated (16% and 40%, respectively) despite the fact that CO did not contain 16∶1 and had only a small amount of 16∶0. Liver TG having a fatty acid (FA) composition markedly different from that of CO and the presence of high levels of 16∶1 and 16∶0 indicate that the TG accumulated in the fatty liver originated from hepatic lipogenesis rather than from dietary fat.