Ethanol and diet-induced alterations in Kupffer cell function.

The effects of 6 weeks of alcohol feeding on phagocytic, metabolic and secretory functions as well as gene expression of hepatic Kupffer cells were evaluated in vitro using cultured Kupffer cells isolated from male Sprague-Dawley rats. The rats were fed either Teklad pelleted rat chow or the 1982 Lieber-DeCarli liquid diet containing 6% ethanol (36% calories) or the same liquid diet with maltose-dextrin isocalorically substituted for the alcohol. Weight gain was greatest in the chow-fed animals and least in those receiving ethanol. The alcohol-containing diet stimulated Kupffer cell phagocytosis, mitochondrial reduction of MTT, secretion of tumor necrosis factor (TNF) and expression of TNF mRNA. However, each of these cell functions was also enhanced by the control Lieber-DeCarli liquid diet alone and the stimulating effect of the control diet often exceeded that induced by ethanol. The results suggest that early in chronic alcohol consumption, the immune system may be stimulated by ethanol, and that during studies of ethanol-induced changes in immune system function, close attention must be given to potentially confounding effects of the diet.