Effects of Dietary Protein on the Liver of Rats in Experimental Chronic Alcoholism ,

Abstract

The lipotropic effect of dietary protein was tested in male rats fed for 16 weeks a liquid diet in which 40% of the calories were provided by alcohol and 25% by an amino acid mixture. Pair-fed controls received a comparable diet in which sucrose isocalorically replaced the alcohol. The livers were examined by light and electron microscopy and levels of hepatic triglycerides, cholesterol and phospholipids were determined at 4, 8, 12 and 16 weeks. In the early stages (4–8 weeks) of the experiment, the alcohol-consuming rats developed more extensive fatty liver than did controls. The accumulation of fat which was only moderate in degree proved to be transient because it later disappeared (12–16 weeks). But fat in livers of control rats did not disappear. Instead, it progressively accumulated during the entire 16-week period. Some mitochondrial alterations and a few Mallory bodies were also observed at the early stages in rats consuming alcohol. However, these ultrastructural changes sharply regressed so that by the end of the experiment livers from both groups were almost indistinguishable and almost normal (aside from the fat in livers of the carbohydrate controls). These data support the concept that even if alcohol has any postulated hepatotoxic effects on the livers of rats, it can be profoundly modified by manipulation of the accompanying diet.