实验性心肌缺血时内源性ET,CGRP和NO水平的变化及心舒平的调节作用

Variation of Endogeneous ET, CGRP and NO in Myocardial Ischemia in Rats and the Regulatory Effect of Xinshuping

目的 :观察异丙肾上腺素造成大鼠心肌缺血模型心肌内ET ,CGRP含量和血清NO水平的变化及中药心舒平对心肌缺血的影响和对这些血管活性物质的调节。方法 :测定异丙肾上腺素引起心肌坏死大鼠血清中心肌酶、NO水平和心肌组织中ET及CGRP含量 ;或结扎冠状动脉造成大鼠心肌缺血 ,观察手术后不同时间心电图变化和心肌梗死范围。结果 :异丙肾模型动物心肌中ET含量明显升高 ,CGRP含量变化不明显 ;血浆中NO浓度亦未见明显改变。心舒平组动物血清的NO浓度明显升高 ;心肌中ET和CGRP含量与模型组相比无显著差异。心舒平可显著降低异丙肾模型的血清LDH和CK水平 ((P <0 .0 5或P <0 .0 1) ;降低冠脉结扎大鼠升高的S T段(P <0 .0 5或P <0 .0 1) ,使心肌梗死范围减小 (P <0 .0 5或P <0 .0 1)。结论 :内源性ET可能参与异丙肾上腺素引起的大鼠心肌缺血 ;心舒平对不同的心肌缺血模型均有明显的保护作用 ,其可能的机制之一是促进血管内皮释放NO。

Objective: To observe the variation of ET and CGRP contents in ischemic heart, and NO level in serum of myocardial damaged rats, and their regulation when with the protection of Xinshuping, a traditional Chinese medicine compound. Method:The models of myocardial ischemia were prepared by subcutaneous injection of isoproterenol or by ligation of coronary artery. Result:ET content in myocardium was significantly increased ( P <0.01), and CGRP content as well as NO level in serum was not changed obviously in the model induced by isoproterenal. However, NO level in serum of rats treated with Xinshuping (ig bid×2.5 d) was markedly raised ( P <0.01) , neither ET not CGRP contents were affected by it. LDH and CK levels in serum of rats were evidently lowered by Xinshuping treatment. S T segment's elevation of ECG was significantly inhibited and myocardial infarction size was reduced markedly by Xinshuping treatment in rats subjected to coronary artery ligature. Conclusion: ET, CGRP or NO is involved in my ocardial infarction caused by isoproterenol. The ischemic damage or dysfunction in different models is obviously protected by Xinshuping. The promotion of NO release from vascular endothelium is probably related with this protective effect.