楤木皂苷C对缺血/再灌注原代大鼠心肌细胞兴奋收缩偶联及CaMKⅡ的调控作用

摘要

Aim To investigate the effects of aralosdie C (SMC)isolated from aralosides on contractile func-tion and calcium transients in ischemia / reperfusion(I/R)-induced rat myocardial injury and the role of CaMK II. Methods The cardiomyocytes were divided into control group,I/ R group,I/ R + SMC group,KN-93+ I/ R + SMC group. The effect of SMC on the con-tractile function and calcium transient of I/ R cells was measured by cell shrinkage and ion concentration sim-ultaneous detection system. Results SMC(8 μmol· L - 1 )improved the contractile function of I/ R cardio-myocytes and the calcium transients,and SMC in-creased the rate of calcium transient and [Ca2 +]i up /down regulation significantly. While CaMK II was blocked by KN-93,the effect of SMC on contractile function and calcium transients was weakened. Con-clusions SMC can significantly improve the systolic function and calcium transients of cardiomyocytes in I/R rats,and the protective effect of SMC on cardiomyo-cytes may be related to CaMK II.%目的 探讨从龙牙楤木总皂苷中分离得到的楤木皂苷C(aralosdie C,SMC)对缺血/再灌注(ischemia/reperfusion,I/R)损伤的大鼠心肌细胞收缩功能和钙瞬变的影响,及钙调蛋白激酶Ⅱ(CaMKⅡ)在其中发挥的作用.方法 采用Langendorff心脏灌流系统分离原代大鼠心肌细胞,分为对照组(Control组)、模型组(I/R组)、楤木皂苷C组(I/R+SMC 8μmol·L-1)、抑制剂组(I/R+KN-931μmol·L-1+SMC 8μmol·L-1),采用细胞收缩与离子浓度同步测定系统同步检测SMC通过调控CaMKⅡ对单个I/R细胞收缩功能和钙瞬变的影响.结果 8μmol·L-1 SMC作用5 min和未加入SMC的I/R成年大鼠心肌细胞收缩功能进行比较,发现SMC处理可明显促进I/R成年大鼠心肌细胞收缩功能的恢复,SMC改善心肌细胞收缩的同时,其钙瞬变也相应改善,并且SMC使钙瞬变幅度和[Ca2+]i上升/下降的速率明显升高,但加入KN-93抑制CaMKⅡ后,除稳态钙息值无变化外,SMC对钙瞬变的作用效果降低.结论 SMC可明显改善I/R成年大鼠心肌细胞的收缩功能和钙瞬变,其作用机制可能与CaMKⅡ有关.