Calpain抑制剂-1对大鼠急性缺血再灌注诱导心肌细胞凋亡的影响

EFFECTS OF CALPAIN INHIBITOR-1 ON CARDIOMYOCYTE APOPTOSIS INDUCED BY ACUTE ISCHEMIA-REPERFUSION IN RATS

采用结扎 SD大鼠左冠状动脉前降支制作在体缺血再灌注模型 ,通过光镜、电镜观察形态学改变 ,用缺口末端标记法 (Td T- m ediated d U TP nick end labeling,TU NEL)检测心肌细胞凋亡 ,研究钙激活中性蛋白酶的特异性抑制剂 calpaininhibitor- 1(CAI- 1)对大鼠急性缺血再灌注诱导的心肌细胞凋亡的影响。结果显示光镜下缺血再灌注组细胞混浊肿胀 ,横纹不清或消失 ,心肌纤维波纹状弯曲 ,可见部分心肌细胞核浓缩。CAI- 1治疗组则以上病理改变明显减轻 ,假手术组未见异常 ;电镜下缺血再灌注组心肌细胞有线粒体肿胀 ,核染色质边集 (chromatic m argination) ,核膜表面凹凸不平 ,核皱缩 (nucleusshrinkage)等凋亡形态学改变 ,CAI- 1治疗组心肌细胞核未见明显异常。TU NEL 检测显示缺血再灌注组大鼠的心肌细胞凋亡数为 17.0± 9.6 8/高倍视野 ,而 CAI- 1治疗组心肌细胞凋亡数为 4.76± 0 .47/高倍视野 ,两组数据在统计学上有显著性差异 (P<0 .0 1) ,假手术组未见凋亡的心肌细胞。研究提示钙中性蛋白酶抑制剂 CAI- 1可明显抑制大鼠急性缺血再灌注诱导的心肌细胞凋亡 。

The left anterior descending branch of coronary artery was ligated to make the heart ischemia reperfusion model in SD rats. TUNEL method was used to detect the cadiomyocyte apoptosis induced by acute ischemia reperfusion in rats, and to observe the effect of calpain inhibitor 1 (CAI 1)on cardiomyocyte apoptosis, and then to see if calpain is involved in the mechanism of cardiomyocyte apoptosis. Light and transmissional electron microscopy were also used to observe the morphologic changes. The results showed that in Ischemia/Reperfusion group the amount of apoptosis cells was 17 0±9 68/HP, and the amount of apoptosis myocardial cells in CAI 1 treated group was significantly reduced to 4 76±0 47/HP, P <0 01. there was no apoptosis myocardial cells in sham operation group. The pathological changes in Ischemia/Reperfusion group under light microscope showed cardiomyocyte swelling, cross striation vague or disappeared, cardiomyocyte fibre wavelike curved, and karyopyknosis . In CAI 1 treated group however, the changes above were significantly alleviated. And under transmissional electron microscope,the ultrastructure changes in Ischemia/Reperfusion group such as cell nucleus shrinkage, mitochondria swelling,chromatic margination,were also alleviated in CAI 1 treated group. There were no obvious abnormity in sham operation group under both light and transmissional electron microscope. These results indicate that calpain inhibitor 1 can significantly inhibit cardiomyocyte apoptosis in acute ischemia reperfusion rat hearts, and calpain is involved in the mechanism of cardiomyocyte apoptosis. \;