Effects of ischemic preconditioning versus ischemic postconditioning on myocardial ischemia-reperfusion-induced inflammatory response in rats / 中华麻醉学杂志

ABSTRACT

Objective To compare the effects of ischemic preconditioning versus ischemic postconditioning on myocardial ischemia-reperfusion (I/R)-induced inflammatory response in rats. Methods Forty male SD rats weighing 290-320 g were randomly divided into 4 groups ( n = 10 each) Ⅰ group sham operatin (group S); Ⅱ group I/R; Ⅲ group ischemic preconditioning (group IPC) and Ⅳ group ischemic postconditioning (group IPOC).Myocardial I/R was induced by 30 min ligation of left anterior descending branch (LAD) of coronary artery followed by reperfusion. In group IPC myocardial I/R was preceded by 3 cycles of ischemia followed by reperfusion (each lasting 5 min) while in group IPOC 3 cycles of I/R (each lasting 10 s) was started at the end of 30 min myocardial ischemia. MAP, HR and RPP ( MAP × HR) were recorded before (baseline) and at 1 and 20 min of ischemia and 60, 120 and 180 min of reperfusion. Venous blood samples were collected at 30 and 180 min of reperfusion for determination of serum concentrations of TNF-α, IL-6, high-mobility group box 1 (HMGB1) and cTnI. The animals were sacrificed at 180 min of reperfusion and the myocardial infarct size was measured. Results Myocardial I/R significantly decreased MAP and RPP and increased myocarcial infarct size, serum concentrations of TNF-α, IL-6,HMGB1 and cTnI in group I/R as compmed with group S. Ischemic pre- and postconditioning significantly increased MAP and reduced myocardial infarct size and I/R-induced increase in serum TNF-α, HMGB1 and cTnI concentrations in group Ⅲ and Ⅳ as compared with group Ⅱ (I/R). The myocardial infarct size was significantly larger and the serum concentrations of TNF-α, IL-6 and HMGB1 were significantly higher in ischemic postconditioning group than in the preconditioning group. Conclusion Ischemic preconditioning is more effective in attenuating the myocardial I/R-induced inflammatory response than the ischemic postconditioning.