Search

The adverse effects of chronic alcohol consumption (mean 6.68 g/kg/d) were assessed in 150 male Sprague-Dawley rats over their life span (25 months). Evaluations were performed at 2, 3, 8, 13, 19, and 25 months of age for changes in nutrition status, biochemical tests for liver injury, compositional changes in liver, and hepatic regenerative capacity. In spite of nearly identical caloric intake, alcohol treatment was associated with nutritional levels 10-30% lower than controls. Maximal changes were observed at the two extremes of ages (2-3 months and 19-25 months). Hence, a nutritional contribution to other adverse changes could not be excluded. Fatty compositional increases (triglycerides) occurred early (5-fold increases after 1 month of treatment) then declined to levels only slightly above controls. Biochemical tests on sera for liver injury (AST and total bilirubin) were consistently higher with alcohol treatment. Regenerative capacity measured by [3H]thymidine uptake after partial hepatectomy was initially elevated in the alcoholic then rapidly declined beyond 7 months of age. In control animals, an age-related decline was also observed but occurred later beyond 12 months of age. Consistent with these adverse effects, ethanol diet survival was poorer than the pair-fed control groups by 15% (median survival for alcoholics, 17 months vs. 20 months in controls).

Animals, chronically treated with alcohol, were inoculated with mycobacteria (bacillus Calmette-Guérin, 10.2 x 10(6) organisms) into the spleen to produce a granulomatous hepatitis. Before infection, chronic alcohol ingestion was associated with a depressed skin test response to phytohemagglutinin, 71.7% of baseline (P = 0.009). Mycobacterial (bacillus Calmette-Guérin) infection stimulated phytohemagglutinin skin test response to 417% of baseline in controls and 299% in alcoholics (P less than 0.001). The hepatic granuloma response was altered with smaller but more numerous granulomas (mean +/- SEM, 81.2 +/- 1.5 microns2 of area with a frequency of 1.8 granulomas per field in alcoholics vs. 129.8 +/- 5.71 microns2 and 1.2 granulomas per field in controls; P less than 0.001). These changes were associated with a 10-fold increase in colony-forming units per gram of liver (54.5 +/- 18.2 in alcoholics vs. 5.6 +/- 1.83 in controls; P = 0.0006). This model offers precise parameters for host response to infection and indicates that alcohol significantly impairs the clearing capacity for mycobacteria from the liver.