The Effect Of Dexmedetomidine Combined With Ischemic Preconditioning On Liver Ischemic Reperfusion Injury In Rats

Objective: To investigate the effect and possible mechanism of dexmedetomidine combined with Ischemic Preconditioning on liver ischemic reperfusion injury in rats.Methods: Sixty healthy male SD rats,weighing(251±18)g,were randomly divided into five groups,twelve rats each group:Sham-operation group(group S),Ischemia- reperfusion group(group IR),Dexmedetomidine Preconditioning group(group Dex),Ischemic Preconditioning group(group IP) and Dexmedetomidine combined with Ischemic Preconditioning group(group Dex+IP). Ischemia-reperfusion model were established according to Pringle’smethod.After 30 minutes’ ischemia and 6 hours’ reperfusion of the liver,the concentrations of ALT,AST,LDH and TNF-αin serum were measured. The liver histological changes were examined after HE staining, the liver cell apoptosis were examined by TUNEL and the expression of heme oxygenase-1 were examined by immunohistochemistry.Results: Serum concentration of ALT,AST,LDH and TNF-α in group IR,Dex,IP and Dex+IP were significantly higher than those in group S(P <0.01);in group Dex,IP and Dex+IP,significantly lower than in group IR(P<0.01);in group Dex+IP,significantly lower than in group Dex and IP(P<0.01).There were no significant difference of the serum concentration of ALT,AST and TNF-α between group Dex and IP(P >0.05), the serum concentration of LDH in group Dex were significantly lower than group IP(P<0.01). Pathological score of group IR, Dex, IP and Dex+IP was significantly higher than that of group S; group Dex, IP and Dex+IP was significantly lower than that of group IR(P< 0.01); group Dex+IP was significantly lower than that of group Dex and IP(P< 0.01),and there were no significant difference between group Dex and IP(P>0.05). The apoptotic index of group IR, Dex, IP and Dex+IP was significantly higher than that of group S; group Dex, IP and Dex+IP was significantly lower than that of group IR(P< 0.01), group Dex+IP was significantly lower than that of group Dex and IP(P < 0.01), and there were no significant difference between group Dex and IP(P>0.05). Compered with group S, the HO-1 score of group IR was improved(P< 0.05), and that of group Dex, IP and Dex+IP was significantly improved(P<0.01); compered with group IR, that of group Dex and IP was improved(P< 0.05) and group Dex+IP was significantly improved(P<0.01); compered with group Dex and IP, that of group Dex+IP was improved(P< 0.05); there were no significant difference between group Dex and IP(P>0.05).Conclusions: Both of Dexmedetomidine Preconditioning and Ischemic Preconditioning can protect liver from ischemia-reperfusion injury in rats to some extent, the combined application of two gives better effects,which is related to the increasing expression of HO-1 to a certain extent.