| Objective Investigating the effects of ischemia reperfusion injury on residual liver re- generation after major hepatectomy in rats and its mechanism. Studying the effects of i- schemic preconditioning on the residual liver regeneration after major hepatectomy in r- ats and verifying whether it can protect the residual liver from ischemia reperfusion inj- ury . Methods female S-D rats were randomized into 3 groups:①Group PH, rats su- bjected to 70% hepatectomy alone.②Group IR, rats were subjected to 30 min of total hepatic ischemia, and 70% hepatectomy was performed just before reperfusion.③Gro- up IP, rats were pretreated with IP (5 hepatic ischemia /10 min reperfusion). At preoper- ative and 0.5h,6h,12h,24h,48 h after operation checkpoint was set.Serum AST an- d ALT activities were measured using a autoanalyzer, expressions of Serum Hyaluronic Acid and TNF-αwere measured with radioimmunoassay , the regenerated liver weight ( RLW ) of rats were measured and the expression of Ki-67and CyclinD1 were determ- ined with immunohistochemical methods in remnant liver tissue. Results①AST/ALT:There were no significant differences in the levels of serum AST and ALT in the all gr- oups at preoperation (P >0.05). After operation they rapidly increased. The expressions of serum AST and ALT were significantly higher in rats of group IR than in group PH from 0.5h -24h after operation (P<0.05). And they were significantly lower group IR ( P <0.05 ).②HA:There were no significant differences in the levels of serum HA in the all groups at preoperation (P >0.05). After partial hepatectomy they rapidly increased, r- eaching the peak values at 12 h. In the early stage (during 12h ) after operation the expr- ession levels of hyaluronic acid were significantly higher in group IR than group PH ( P <0.05 ). And they were significantly lower group IR (P<0.05).③RLW:There were no significant differences in the RLW of rats in the all groups at preoperation (P > 0.05). They rapidly increased after partial hepatectomy. At 12h and 24 h after operation in rats of group PH, RLW were significantly higher than group IR (P<0.05). RLW were signif- icantly lower in IP rats than group IR at 24 h after operation (P<0.05).④Cyclin D1/ Ki-67:The expression of Cyclin D1 and Ki-67 in the all groups at preoperation was low, and they were not significant different ( P > 0.05). The expression of Cyclin D1 and Ki- 67 in the all groups at preoperation was low, and they were not significant different (P > 0.05). After partial hepatectomy they rapidly increased. The expression of CyclinD1 and Ki-67 reached the peak at 24 h after operation in group PH (5.92±0.54,6.13±1.33), and they were significantly higher compared with those of groups IR and group IP ( P<0.05). Then in group IR and group IP they reached the peak values at 48 h later.And a signific- ant decrease in the expression of Cyclin D1 and Ki-67 was observed after 24 and 48 h of reperfusion in the group IP when compared with those in the groups PH and IR ( P < 0.05 ).⑤TNF-α:There were no significant differences in the levels of serum TNF-αin the all groups at preoperation(P > 0.05). After partial hepatectomy they rapidly increas- ed, and the peak value was observed at 12 h in group PH, 6h in groups IR and IP. The e- xpressions of serum TNF-αafter 0.5h and 6h of operation were significantly higher in r- ats of group IR than in group PH , and there were no significant differences in group IP and IR ( P<0.05).⑥IL-6:There were no significant differences in the levels of serum IL-6 in the all groups at preoperation ( P > 0.05). After partial hepatectomy they rapidly increased, and the peak value was observed at 12 h in group PH. They were significan- tly high in rats of group IR and group IP in the early stage after operation (at 0.5h and 6h ).And in the late stage after operation (at 24h and 48h ) they were significantly high- er in rats of group PH than group IR. Then there were no significant differences in gro- up IR and IP( P<0.05 ). Conclusion①Ischemia reperfusion injury impairs the resid- ual liver regeneration after major hepatectomy in rats.The increased expression of TNF-αand the suppressed expression of IL-6 may be the causes of the inhibited liver regen- eration.②Ischemic preconditioning (5min hepatic ischemia /10 min reperfusion) impa- irs the residual liver regeneration after major hepatectomy, and neither TNF-αnor IL-6 is the critical role.③In the rat model of major hepatectomy under hepatic blood in flow occlusion the protection of ischemic preconditioning (5min hepatic ischemia /10 min reperfusion) from ischemia reperfusion injury disappears. |
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