Effects of ethanol on liver regeneration after partial hepatectomy in rats.

The effect of ethanol on hepatic regeneration after partial hepatectomy was studied. Ethanol was administered in a nutritionally adequate liquid diet 4 times daily by gastric intubation. The dose of ethanol was selected to maintain a continuous level of ethanol in the animals throughout the experiment. Treatment was started 24 hours before the operation and continued for 6 days. Control animals were pair-fed on a diet in which ethanol was isocalorically replaced by carbohydrate. On the 1st, 2nd, 3rd and 5th day after the operation the incorporation of [3H]-labelled thymidine into liver DNA and [14C]-labelled leucine into liver proteins and the mitotic index of the regenerating liver was assessed. On the 2nd and 3rd day the incorporation of labelled thymidine into DNA in the regenerating livers of alcohol-fed animals was significantly (P less than 0.05) lower than in pair-fed controls. The inhibition was most pronounced (60%) on the 2nd day after the operation. This was associated with a significant (P less than 0.01) decrease in mitotic activity, which was most pronounced in the periportal area. At the end of the experiment, however, DNA content was similar both in ethanol-treated and in control livers. It is concluded that the continuous presence of ethanol retards DNA synthesis and cell division of regenerating rat liver after partial hepatectomy. The incorporation of [14C]-leucine into liver proteins was inhibited by ethanol on the second day of regeneration (P less than 0.01), and at the end of the experiment the livers of ethanol-fed rats contained more protein than the control livers. This accumulation of proteins was accompanied by hepatomegaly.