Objective To elucidate the protective effect and potential mechanisms of preconditioning on hepatic IR injury in steatotic livers and explore the optimal ischemic time.Methods The fatty liver model was made by feeding high-fat diet.The changes in serum and in liver sample were evaluated for the different ischemic time of preconditioning liver.Histological analyses of liver were performed and hepatic fatty infiltration were evaluated by sudan III stain.Results 1.The preconditioning consisting of 15 minutes of ischemia followed by 10 minutes of reperfusion was performed (15 min +10 min IP) .The extent and number of necrosis areas at 24 hours after hepatic reperfusion was markedly increased in fatty livers.By contrast, the histological study in normal liver showed moderate.2.The level of serology and the changes of MDA, MPO in liver in 5 or 8-10 min preconditioning group were lower than the other preconditioning groups in fatty liver, while the SOD activity level was significantly higher than the others (P< 0.05) .The serological level of NO in IP group was significantly higher than the corresponding IR group (P< 0.05) .In fatty liver group, the level of NO in 5 or 8-10 min IP group was significantly higher than the others (P< 0.05) .Conclusion Liver with fat infiltration can aggravate ischemia-reperfusion injury in rats.Ischemia preconditioning can also increase the tolerance of fatty liver induced by high-fat diet to hepatic ischemia-reperfusion injury in rats.The protective effect of ischemia preconditioning is distinct in different ischemic time of preconditioning, and the 5-8 min and 10 min IP was superior to the others.
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