Induction of different types of cell death after normothermic liver ischemia-reperfusion

Normothermic liver ischemia-reperfusion (I-R) may induce hepatocellular autophagy, apoptosis, and necrosis. The aim of this study was to investigate these three types of cell death in normothermic liver I-R in rats. A segmental normothermic ischemia of the liver was induced for 120 minutes. Liver autophagy was evaluated by transmission electron microscopy and LC3 (Light Chain 3) immunohistochemical studies. Liver apoptosis was assessed by FLIVO (FLuorescence in vIVO) and TUNEL (TdT-mediated dUTP nick end labeling) assays. Liver necrosis was determined by optical microscopic examination. Autophagy was increased in ischemic liver lobes at 6 hours after reperfusion, compared with nonischemic lobes. Fluorescence microscopy showed in situ caspase-3 and -7 specific activity to be increased in ischemic liver lobes after 6 hours of reperfusion, compared with nonischemic lobes. Quantitative analysis of apoptotic cells evaluated by the TUNEL method showed a clearly significant increase in ischemic liver lobes at 6 hours after reperfusion, compared with nonischemic lobes. Necrotic cell death was significantly increased in ischemic liver lobes at 6 hours after reperfusion, compared with nonischemic lobes (P < .005). In conclusion, 120 minutes normothermic liver I-R resulted in increased autophagic, apoptotic and necrotic cell death.