茶皂苷减轻心肌缺血再灌注损伤的实验研究

The study of tea saponin on attenuating myocardial ischemia reperfusion injury

目的观察茶皂苷对心肌缺血再灌注(MIR)损伤的保护作用并探讨其机制,为茶皂苷防治心肌缺血再灌注损伤提供科学的依据。方法采用左冠状动脉前降支结扎30min,复灌45min建立在体大鼠MIR模型。SD大鼠随机分成6组:假手术组,模型组,生理盐水组,维拉帕米组,小剂量、大剂量茶皂苷组。连续纪录Ⅱ导联心电图,于再灌注后取心尖部缺血区心肌,检测心肌细胞膜Na+-K+-ATP酶、Ca2+-ATP酶活性和线粒体内Ca2+含量。结果MIR损伤时,心肌细胞膜Na+-K+-ATP酶、Ca2+-ATP酶活性显著下降,线粒体内Ca2+含量升高;心电图ST段显著抬高,并发生明显的室性心律失常。茶皂苷可明显对抗上述变化。结论茶皂苷可通过减轻细胞内钙超载对MIR损伤起保护作用。

Objective To explore the effect of tea saponin attenuating myocardial isehemia reperfusion （MIR） injury of rats and to elucidate the possible mechanisms. Methods Myocardial ischemia reperfusion models were obtained by ligating left anterior descending coronary artery 30 min,followed by 45 min reperfusion.SD rats were randomly divided into six groups with 8 rats in each ：Sham group,MIR group,normal saline group, verapamil group,low dose and high dose tea saponin group.Lead Ⅱ ECG was recorded.After reperfusion,left ventricular myocardium samples of ischemia area were processed immediately.The activity of Na^＋-K^＋-AT Pase, Ca^2＋-ATPase and concentration of Ca^＋ in mitochondrion were measured. Results The activity of Na^＋ -K^＋ -ATPase and Ca^2＋-ATPase in myocardial cytomembrance was significantly decreased while intramitochondrial Ca^2＋ content was markedly raised,ST segment was significantly elevated and ventricular arrhythmias occulted during reperfusion stage in MIR rats. While in two tea saponin intervention groups; the above-mentioned changes were attenuated markedly. Conclusion Tea saponin can protect MIR injury by attenuating intracellular Ca^2＋ overloading.