Acute alcohol produces hypoxia directly in rat liver tissue in vivo: Role of Kupffer cells

Previous studies using liver slices and isolated perfused rat liver have suggested that ethanol causes hypoxia by increasing oxygen consumption. However, ethanol also increases blood flow to the liver, a phenomenon that may counteract the effects of hypermetabolism by increasing oxygen delivery. Thus whether ethanol causes hypoxia in vivo remains unclear. To clarify this important point, female Sprague-Dawley rats (100-125 g) simultaneously received pimonidazole (120 mg/kg ip), a 2-nitroimidazole hypoxia marker, and one large dose of ethanol (5 g/kg ig), which increase hepatic oxygen uptake dramatically and elevate ethanol metabolism (swift increase in alcohol metabolism) in 2-3 h. After 2 h, ethanol significantly increased the accumulation of bound pimonidazole in pericentral regions of the liver lobule. Treatment of animals with the Kupffer cell-specific toxicant, GdCl3 (10 mg/kg iv, 24 h before experiment), blocked ethanol-induced increases in pimonidazole binding. It is concluded that one large dose of ethanol causes pericentral hypoxia in rat liver tissue in vivo and that Kupffer cells are involved.