Role of HSP70 in ozone preconditioning-induced reduction of hepatic ischemia-reperfusion injury in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of heat shock protein 70 (HSP70) in ozone preconditioning-induced reduction of hepatic ischemia-reperfusion (I/R) injury in rats.Methods Twenty-four pathogen-free healthy male Sprague-Dawley rats,aged 8 weeks,weighing 250-300 g,were divided into 4 groups (n=6 each) using a random number tablesham operation group (group S),group I/R,ozone preconditioning group (group OP) and HSP70 inhibitor quercetin group (group Q).Hepatic I/R injury was induced by clamping the branches of hepatic artery supplying left and middle lobes of the liver,portal vein and bile vessel for 45 min,followed by 2 h of reperfusion.In group OP,the mixture of ozone and oxygen was intraperitoneally injected at the concentration of ozone 50 μg/ml and bolus dose 1 mg/kg once a day for 5 consecutive days before operation.In group Q,quercetin 7 mg/kg was intraperitoneally injected at 1 h before injecting the mixture of ozone and oxygen.Blood samples from the abdominal aorta were collected at 2 h of reperfusion for determination of serum alanine transaminase (ALT) and aspartate transaminase (AST) activities and concentrations of interleukin-1beta (IL-1β),IL-6 and tumor necrosis factor-alpha (TNF-α) in serum (by enzyme-linked immunosorbent assay).The animals were sacrificed after blood sampling,and hepatic tissue specimens were collected for detection of activated caspase-3 expression (by Western blot) and cell apoptosis (by TUNEL).Apoptotic index (AI) was calculated.Results Compared with group S,the serum ALT and AST activities,concentrations of IL-1β,IL-6 and TNF-α in serum and AI were significantly increased,and the expression of activated caspase-3 was up-regulated in group I/R (P＜0.05 or 0.01).Compared with group I/R,the serum ALT and AST activities,concentrations of IL-1β,IL-6 and TNF-α in serum and AI were significantly decreased,and the expression of activated caspase-3 was downregulated in group OP (P＜0.05 or 0.01).Compared with group OP,the serum ALT and AST activities,concentrations of IL-1β,IL-6 and TNF-α in serum and AI were significantly increased,and the expression of activated caspase-3 was up-regulated in group Q (P＜0.05 or 0.01).Conclusion The mechanism by which ozone preconditioning reduces hepatic I/R injury is related to activating HSP70 and inhibiting inflammatory responses and cell apoptosis in rats.