Effect of alcohol on the functions of Kupffer cells and splenic macrophages in rats

Uptake of endotoxin and production of tumor necrosis factor (TNF) by Kupffer cells and splenic macrophages were measured in chronically alcohol-fed rats. Twenty male Sprague-Dawley rats, weighing 200-250 g, were pair-fed by isocaloric control and ethanol-containing Lieber-DeCarli liquid diets for 6 weeks. Endotoxin uptake and TNF production of Kupffer cells and splenic macrophages in the chronic ethanol load-group were significantly (P < 0.001) greater than those in the control group. The increase in endotoxin uptake was more prominent in Kupffer cells and the increase in TNF production was more marked in splenic macrophages in the chronic ethanol group. When these cells were precultured in the medium containing 10-100 mM ethanol, the endotoxin uptake and TNF production of Kupffer cells isolated from control and chronic ethanol-fed rats were decreased in proportion to the concentration of ethanol in the culture medium. However, the addition of ethanol to the culture medium did not affect the endotoxin uptake and TNF production of splenic macrophages. These results support the hypothesis that the splenic macrophages are important for endotoxin uptake, and excessive production of TNF in rats given large amounts of alcohol.