摘要目的:探讨受体相互作用蛋白激酶3(RIPK3)介导的程序性坏死在糖尿病因素取消大鼠七氟烷后处理心肌保护效应中的作用。方法:取糖尿病造模成功的大鼠80只，4~5周龄，体重90~100 g，采用随机数字表法分为4组( n＝20)：假手术组(Sham组)、心肌缺血再灌注组(I/R组)、七氟烷后处理组(SP组)、七氟烷后处理+RIPK3抑制剂GSK-872组(GSK组)。采用结扎左冠状动脉前降支40 min，再灌注120 min的方法制备糖尿病大鼠心肌缺血再灌注损伤模型。SP组于再灌开始时吸入2.4%七氟烷15 min；GSK组于术前24、2 h时腹腔注射GSK-872 3.3 mg/kg(溶于生理盐水)，其他操作同SP组。再灌注120 min时，取腹主动脉血样，检测血清LDH和CK-MB浓度；取心肌组织，TTC染色法确定心肌梗死面积百分比，免疫组化法检测RIPK3的表达，Western blot法检测RIPK3、磷酸化钙离子/钙调素依赖性蛋白激酶Ⅱ(p-CaMKⅡ)、磷酸化混合谱系激酶结构域样假激酶(p-MLKL)的表达水平，透射电镜观察心肌超微结构。 结果:与Sham组比较，I/R组血清LDH和CK-MB浓度、心肌梗死面积百分比升高，心肌组织RIPK3、p-MLKL和p-CaMKⅡ表达上调( P<0.05)，心肌细胞损伤严重。与I/R组比较，SP组上述指标差异无统计学意义( P>0.05)。与SP组比较，GSK组血清LDH、CK-MB浓度和心肌梗死面积百分比降低，心肌组织RIPK3、p-MLKL和p-CaMKⅡ表达下调( P<0.05)，心肌细胞损伤程度减轻。 结论:糖尿病因素取消大鼠七氟烷后处理心肌保护效应的机制与其过度激活RIPK3介导的程序性坏死有关。

abstractsObjective:To investigate the role of receptor-interacting protein kinse3 (RIPK3)-mediated necroptosis in diabetic mellitus-caused abolition of cardioprotection induced by sevoflurane postconditioning in rats.Methods:Eighty rats with diabetes mellitus, aged 4-5 weeks, weighing 90-100 g, were divided into 4 groups ( n=20 each) using a random number table method: sham operation group (group Sham), myocardial ischemia-reperfusion (I/R) group (group I/R), sevoflurane postconditioning group (group SP) and sevoflurane postconditiong plus RIPK3 inhibitor GSK-872 group (group GSK). Myocardial I/R was induced by 40 min occlusion of the left anterior descending branch of the coronary artery followed by 120 min reperfusion.In group SP, 2.4% sevoflurane was inhaled for 15 min at the beginning of reperfusion.In group GSK, GSK-872 3.3 mg/kg (dissolved in normal saline) was intraperitoneally injected at 24 and 2 h before surgery, and the other treatments were similar to those previously described in group SP.After 120 min of reperfusion, blood samples from the abdominal aorta were collected for determination of concentrations of serum lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB). Myocardial tissues were taken for determination of percentage of myocardial infarct size (by TTC staining) and expression of RIPK3, phospho-Ca 2+ -calmodulin-dependent protein kinase Ⅱ (p-CaMKⅡ) and phospho-mixed lineage kinase domain-like protein (p-MLKL) (by Western blot), and the ultrastructure of myocardium was observed by transmission electron microscopy. Results:Compared with group Sham, the serum LDH and CK-MB concentrations and percentage of myocardial infarct size were significantly increased, the expression of RIPK3, p-MLKL and p-CaMKⅡ in myocardial tissues was up-regulated ( P<0.05), and the damage to cardiomyocytes was severe in group I/R.Compared with group I/R, no significant change was found in the parameters mentioned above in group SP ( P>0.05). Compared with group SP, the serum LDH and CK-MB concentrations and percentage of myocardial infarct size were significantly decreased, the expression of RIPK3, p-MLKL and p-CaMKⅡ in myocardial tissues was down-regulated ( P<0.05), and the damage to cardiomyocytes was reduced in group GSK. Conclusion:The mechanism of diabetic mellitus-caused abolition of cardioprotection induced by sevoflurane postconditioning is related to excessive activation of RIPK3-mediated necroptosis in rats.