Ischemia Reperfusion Injury In The Resected Liver Improves Liver Regeneration In Rats

Objective:To investigate the effects of ischemia reperfusion injury beforepartial hepatectomy on liver regeneration and explore its mechanismMethods :1.Experimental design: Seventy five male healthy SD rats weighing260+20g purchased from Shanghai SLAC Laboratory Animal Co. Ltd were used inthis study. The rats were kept under constant environmental conditions with a 12-hlight-dark cycle, and free access to food and water. Animals were not fasted prior tothe operation. The rats were randomly classified into 5 groups:group control,inwhich rats were only subjected to 70％hepatectomy; group I10R30,70% liverhepatectomy after 10 min of ischemia and 30 min of reperfusion in the resected liver;group I60R30 ;group I90R30 ;group I90R60. 2. Animal model:The animal wasanesthesized by Ketamine (80 mg/kg) in the intraperitoneal injection,a rat was givenby Ketamine(40mg) in twice. A midline incision was made to expose the liver.Groupcontrol:the middle and left lobes of the liver were resected straightway; GroupI10R30: Portal vein and liver artery that drain blood to middle and left lobes of theliver were dissected and the blood flow was blocked with a pair of vessel clamps．After 10 minutes of ischemia,30 minutes of reperfusion Was allowed by releasing theclamps,and then the middle and left lobes of the liver were resected. By analogy, group I60R30 , group I90R30 and group I90R60 were constructed.3. Test items:At6h,12h and 24 after operation, RLW was determined; serum ALT and AST activitieswere measured using autoanalyzer; the levels of serum TNF-αwere determined byELISA and the expression level of KI-67 was measured with immunohistochemicalmethods in residual liver tissue; The pathological changes of liver were observed .Results: At 12h after partial hepatectomy, the expression levels of RLW and KI-67in group I60R30, group I90R30 and group I90R60 were significantly higher than thatin the group control (P<0．05); At 24h after operation, The expression levels ofRLW and KI-67 in group I90R30 and group I90R60 were significantly higher thanthat in the group control (P<0．05); The levels of ALT and AST in rats with ischemiareperfusion injury were higher than that in the group control(P<0．05). At 6h and 12hafter operation, the expression levels of TNF-αin group I60R30,I90R30 and I90R60were significantly higher than that in the group control(P＜0.05). At 24h afteroperation, the expression levels of TNF-αin group I90R60 were significantly higherthan that in the group control(P＜0.05). The changes of the histomorhology on therat's liver were slight.Conclusion: Ischemia reperfusion injury in the resected liver before majorhepatectomy could improve liver regeneration of the remnant liver in rats. The highexpression of induced TNF-αmay be one of the reasons.