Injurious effects of ethanol on rat Kupffer cells

The effects of ethanol on rat Kupffer cells were studied functionally and morphologically. Eight g ethanol per kg body weight per day was intragastrically administered to rats for 7 days. An isocaloric glucose solution was administered to control rats. The phagocytic activity of the reticuloendothelial system was measured by the carbon clearance method (57 mg carbon particles per kg body weight) on the 7th day. Kupffer cells having phagocytized carbon particles were counted under the light microscope. Kupffer cells were also observed by scanning electron microscopy. Both the carbon clearance and Kupffer cell number were lower in ethanol-administered rats (32 +/- 8 X 10(-4) mg/ml; 0.6 +/- 0.3/0.01 mm2 liver lobule) as compared to control rats (63 +/- 15; 3.1 +/- 1.0). Microvilli and filopodia of Kupffer cells were fewer in ethanol-administered rats than in control rats. Carbon clearance correlated with Kupffer cell number per 0.01 mm2 liver lobule and liver weight. These results suggest that the decrease in carbon clearance induced by ethanol is due mainly to the decrease in Kupffer cell number and partly to the decrease in Kupffer cell activity as demonstrated by the disappearance of microvilli and filopodia.