家兔实验性心肌缺血的定量酶组织化学研究

QUANTITATIVE ENZYMOHISTOCHEMICAL STUDIES OF EXPERIMENTAL MYOCARDIAL ISCHEMIA IN RABBITS

目的 研究心肌缺血后琥珀酸脱氢酶 (SDH)、酸性磷酸酶 (ACP) 及线粒体腺苷三磷酸酶 (mitoATPase)的情况, 力求寻找一种更为理想的诊断早期心肌缺血的方法。方法 结扎家兔左冠状动脉主干建立实验性心肌缺血的动物模型, 常规组织学和透射电镜技术观察缺血心肌的组织学和超微结构改变, 脱氢酶染色观察大体心肌的缺血情况, 并分别采用硝基四氮唑蓝法、硝酸铅法和镁离子激活法研究结扎后0 .5、1、2、4、8、12h左室前壁SDH、ACP以及 mitoATPase水平的动态变化, 显微图像分析系统测定其平均灰度值进行定量分析。结果 ①缺血后1h SDH活性开始降低, 随着缺血时间的延长其表达水平不断下降, 在1、2、4、8、12h平均灰度值分别为97 8488±8 .13077、105 376±6 .06887、112. 584±5. 18463、124. 886±12 .1167和144 .605±13. 9902 (P<0 01) ②ACP活性在缺血后 4h明显增强, 随着缺血时间的延长其表达水平不断增强, 缺血后4、8、12h平均灰度值分别为 186 494±15 7005、173. 158±12. 6425 和 162. 506±11. 5195(P<0 .01) ③缺血2h后mitoATPase表达水平显著下降, 其强度随着缺血时间的延长不断减低, 缺血 2、4、8、12h平均灰度值分别为164 .153±15. 6087、171. 256±17. 3428、183. 518±18 .0872 和 203.

Objective To study the changes in the expression level of succinic dehydrogenase (SDH), acid phosphatase (ACP) and mitochondria adenosine triphosphatase (mitoATPase) after myocardial ischemia for the sake of early diagnosis of myocardial ischemia. Methods Twenty-two rabbits were used to establish the experimental myocardial ischemia model by ligating the main branch of left coronary artery. We used NBT method, Lead Nitrate method and Mg 2+-activated method to study the activity change of SDH, ACP and mitoATPase of the left ventricle anterior wall at 0.5, 1, 2, 4, 8 and 12 hours after ischemia. Quantitatively analyze changes in the average gray value were quantitatirely analyzed by micro-image analysis system.Results ①The enzyme activity of SDH began to descende one hour after ligation, with the prolongation of ischemia. At 1, 2, 4, 8 and 12 h the average gray value was 97.8488±8.13077, 105.376±6.06887, 112.584±5.18463, 124.886±12.1167 and 144.605±13.9902 (P<0.01) ②Four hours were required for demonstrating the obvious activity change of ACP, and the enzyme activity increased obviously with the length of ischemia period. The average gray value was 186.494±15.7005, 173.158±12.6425 and 162.506±11.5195 at 4, 8 and 12 h after ligation (P<0.01) ③Two hours after the occlusion, the enzyme activity of mitoATPase began to decrease gradually with the extension of myocardial ischemia. At 2, 4, 8 and 12 hours after ligation, the average gray value was 164.153±15.6087, 171.256±17.3428, 183.518±18.0872 and 203.218±11.7952, respectively (P<0.01). Conclusion The decrease of SDH and mitoATPase and the increase of ACP activity play an important role in the process of myocardial ischemia.