Superoxide anion release into the hepatic sinusoid after an acute ethanol challenge and diaphorase activity in Kupffer cells

Using a ferricytochrome c reduction method, superoxide anion release into t he hepatic sinusoid after an acute ethanol challenge was examined in a live r perfusion model in rats. Superoxide anion release was detectable in rats given ethanol as a bolus of 1.75 g/kg followed by a continuous ethanol infu sion of 0.25 g/kg/hr for 3 hours. By contrast, it was nor detectable in rat s given ethanol in the same way for 30 minutes. TNF-alpha was not detectabl e in the sera of any rats in both groups and no leucocyte infiltration was shown in their liver specimens. To know the possible source of the superoxi de onion, Kupffer cells were isolated from rat livers and the fractions wer e incubated with 0.5 mu M nitroblue tetrazolium and 1 mu M beta-NADPH. This resulted in the appearance of the peak of absorbance Lit 590 nm, indicatin g that Kupffer cells contain an electron transfer system from beta-NADPH. T his may, at least in part, contribute to the formation of superoxide anion that is released into the hepatic sinusoid caused by an acute ethanol chall enge.