巯甲丙脯酸降低缺血再灌注心律失常的发生率

REDUCTION OF INCIDENCE OF ISCHEMIA-REPERFUSION INDUCED VENTRICUAR FIBRILLATION BY CAPTOPRIL

本工作用放射免疫法、荧光组织化学等方法探讨心肌儿茶酚胺和前列环素在大鼠缺血再灌注心律失常发生中的作用。结扎左冠状动脉造成局部心肌缺血然后再灌注。在缺血再灌注组，缺血再灌注引起的心室纤颤发生率为７８％；在巯甲丙脯酸组，巯甲肉脯酸预处理可使缺血再灌注心室纤颤发生率下降了６５．５％；与缺血再灌注组相比，巯甲丙脯酸组的心肌儿茶酚胺含量、心肌６－酮－ＰＧＦ；。（６－Ｋｅｔｏ－ＰＧＦ１α）的含量明显升高（Ｐ＜０．０１），血栓素Ｂ２（ＴｘＢ２）的含量和ＴｘＢ２／６Ｋｅｔｏ－ＰＧＦ１α的比值则明显降低（Ｐ＜０．０１）。在ＡｕｇⅡ组，ＡｎｇⅡ灌流可逆转巯甲丙脯酸的保护作用，使心室纤颤发生率升高至８５％，心肌儿茶酚胺的含量与缺血再灌注组无显著性差异（Ｐ＞０．０５）。上述结果表明，巯甲丙脯酸可显著降低缺血再灌注引起的心室纤颤发生率，这种作用可能是由于抑制了ＡｕｇⅡ的生成，减少心肌儿茶酚胺的释放以及抑制ＴｘＡ２的生成和促进ＰＧＩ２的合成。

To investigate the role of catecholamine and prostacyclin in ischemia reperfusioninduced ventricular fibrillation, experiments were performed in rat hearts using methods of radioimmunoassay and fluorohistochemistrochemistry. Regional myocardial ischemia was induced by ligation of the left coronary artery followed by reper fusion. In the ischemia reperfusion group,ventricular fibrillation during reperfusion took place in 78% of the hearts.In the group pretreated with captopril, the incidence of ventricular fibrillation decreased significantly (65. 5 % ). In comparision with the ischemia reperfusion group,myocardial catecholamine content and 6-keto-PGFlαof the captopril group were significantly increased (P< 0. 01 ) while thromboxane B2 (TxB2) and TxB2/6-keto-PGFlαwere decreased (P<0.01 ).In Aug Ⅱgroup, infusion of angiotensin Ⅱreversed the protective effect of captopril and restored the incidence of ventricular fibrillation (85 % ),while myocardial catecholamine content was not different from the ischemia reperfusion group (P>0. 05).Above results suggest that reduction of the incidence of ischemia reperfusion-induced ventricular fibrillation by captopril may be due to its inhibition on angiotensin Ⅱproduction with consequent reduction of the release of myocardial catecholamine, suppression of TxB2 and promotion of PGI2 synthesis.