Effects of isoflurane delayed preconditioning on Bcl-2 protein expression and IL-10 level in ischemiareperfusion myocardium of rabbit

Objective:To investigate the protective effect of isoflurane delayed preconditioning on myocardial ischemia reperfusion injury and the potential mechanisms in rabbit. Methods:Thirty New Zealand male white rabbits were randomly assigned to 3 groups:(1)Control group;(2)I/R group;(3)2.0% isoflurane group. Group 3 was exposed to 2.0% isoflurane-100% oxygen for 2 h. Group 1 and group 2 were exposed 2 h to 100% oxygen serving as untreated controls. Twenty-four hours later group 2 and group 3 underwent 40 min of coronary occlusion followed by 2 h of reperfusion. Blood samples were taken from arterial line at 20min before occlusion(T1)、20min after occlusion(T2)、40min after occlusion(T3)、1h after reperfusion(T4) and 2h after reperfusion(T5) for determination of the plasma level of IL-10. At the end of the reperfusion, infarct size(IS) and area at risk(AAR) were defined by Evans and TTC staining. The heart was harvested and level of the Bcl-2 expression was determined by Western Blot analysis. Results: The Bcl-2 level of group 3 was significantly higher than that of group 2(P0.05). Isoflurane significantly(P0.05) reduced infarct size(19.7%±2.8% in group 3) of the left ventricular area at risk as compared with control group (37.8%±1.7% in group 2). Group 3 had a higher levels of IL-10 than that of Group 2. Conclusion: Isoflurane can promote Bcl-2 expression and increase the IL-10 level during ischemia reperfusion, which may be one of molecular mechanisms of isoflurane delayed preconditioning on cardioprotection.