Activation of hepatic macrophage contributes to hepatic necrosis after post-ischemic reperfusion in alcoholic fatty liver

Abstract

Fatty livers are vulnerable to ischemia/reperfusion (I/R) injury. We investigated the role of hepatic macrophages in the I/R injury in the fatty liver. Rats with alcoholic or nonalcoholic fatty liver were subjected to hepatic warm ischemia for 30 min. A bolus of gadolinium chloride (GdCl 3) was injected intravenously twice before I/R to block hepatic macrophage activity. Alcoholic fatty liver developed more extensive hepatic necrosis with neutrophil infiltration in association with a higher production of cytokine-induced neutrophil chemoattractant (CINC)-1, a potent neutrophil chemokine in rat, after I/R than the nonalcoholic fatty liver or control liver without steatosis. Hepatic apoptosis after I/R increased to a similar degree (3-fold) in each of the two fatty liver models, compared with the control liver. Alcoholic fatty liver exposed to I/R showed a rapid increase in nuclear factor-kappa B (NF-κB) binding activity. The GdCl 3 pretreatment significantly reduced NF-κB binding activity, CINC-1 level and necrosis in alcoholic fatty liver, despite no significant decrease in the extent of apoptosis. Our results suggest that the activation of hepatic macrophages in alcoholic fatty liver may contribute to hepatic necrosis after I/R, and that the apoptosis might be less dependent on the macrophage activity.