Effects of Hyperbaric Oxygen on Myocardial Ischemia and Reperfusion Injury and the Relationship with Hsp70

Objective To investigate the effects of hyperbaric oxygen and the relationship with Hsp70 on myocardial ischemia and reperfu- sion injury of rabbits. Methods 56 family rabbits were allocated to each of 3 groups(n=8)randomly:pseudo-operation group(group P),is- chemia and reperfusion group(group IR),hyperbaric oxygen group(group HBO). Animals in each group except group P,experienced LDA oc- clusion for 60 minutes and reperfusion for 120 minutes. Animals in group HBO received hyperbaric oxygen infusion before ischemia and during reperfusion. Activity of superoxide dismutase(SOD),quantity of malondialdyde(MDA)in myocardium was detected,and infarct size was cacu- lated. Results MDA quantity in group IR,HBO raised significantly and activity of SOD decreased significantly compared with group P. Infarct size of area at risk in group HBO(25.2±4.2)% was significantly lower than that in group IR(45.5±4.3)%. The expression of Hsp70 was sig- nificantly up-regulated in group HBO during reperfusion. Conclusion Hyperbaric oxygen infusion could reduce infarct size of area at risk, protect the activity of SOD and reduce the product of MDA,up-regulate the expression of Hsp70.