Effect of long-term administration of ethanol to the rat: lipids, collagen and other proteins, and Mallory bodies in the liver.

Rats drank ethanol, on the average 1.20 g/100 g body weight, for various periods up to nearly 300 days. Experimental variables included a high-fat, low-protein diet, administration of additional ethanol by stomach tube, and CCl4 injections instead of ethanol. Growth was retarded by all the variables, especially by the high-fat, low-protein diet. The specific histological finding in the ethanol groups was the presence of Mallory bodies. Significant increase in total liver lipids was caused by ethanol, and rapid fat accumulation, inflammatory changes, and even fibrosis and cirrhosis by the high-fat, low-protein diet and the CCl4 injections. Ethanol raised the concentrations of collagen and soluble protein in the liver; the collagen content was increased also by the high-fat, low-protein diet and the CCl4 injections. The incorporation of proline to collagen was stimulated in incubated liver slices from both ethanol-treated and high-fat, low-protein-fed rats. These treatments also increased the concentration of free proline in the liver, thus augmenting the protein synthesis in fibroblasts.