大鼠冠脉微血栓后心肌细胞丢失与细胞凋亡实验研究

目的：探讨冠状动脉微血栓形成后心肌细胞慢性丢失及其机制。方法：以SD大鼠为研究对象，自主动脉根部注入月桂酸钠，诱发冠脉微血栓，建立冠脉微血栓模型，复苏后喂养4周。20只大鼠分成：冠脉微血栓组（10例）及对照组（10例）。应用显微图像细胞学定量分析技术结合HE染色测定心肌细胞核密度（MND）、结合末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸缺口末端标记（TUNEL）法染色及活化型半胱氨酸天冬氨酸酶（caspase）-3免疫组化法测定心肌细胞凋亡率（MAR1和MAR2）。结果：4周时冠脉微血栓组与对照组比较：心肌细胞凋亡率显著增加MAR1（0．47±0．10）％：（0．08±0．02）%，P〈0．01；MAR2（0．49±0．14）％：（0．04±0．02）％，P〈0．01]；MND显著下降（2041±363）个／mm^2：（3067±254）个／mm^2，P〈0．01]；MND与MAR1、MAR2均呈高度负相关（r=-0．73，P〈0．01；r=-0．86，P〈0．01）。结论：冠状动脉微血栓后慢性期心肌细胞凋亡率增高，心肌细胞成分严重丢失。

Myocyte apoptosis and loss following coronary artery microthrombosis in rats

Objective： To explore whether myocyte apoptosis lead to progressive myocyte loss following coronary artery microthrombosis （CAM）. Methods： Sodium laurate was injected into aorta root during clamping the ascending aorta to create a model of CAM. Twenty rats were divided into： CAM group （n= 10） and control group （n= 10）. A microscopy incorporated with an image analysis software （ImagePro--4） was employed to calculate the myocyte apoptosis rate in combined with TUNEL -- staining （MAR1） and immunohistochemical staining for activated caspase -- 3 （MAR2）, and to determine the myocyte nuclear density （MND） in combined with HE--staining. Results： Compa- ring with control group, the myocyte apoptosis significantly increasedMAR1（0.47±0.10）%：（0.08±0.02）%,P〈0.01;MAR2（0.49±0.14）%：（0.04±0.02）%,P〈0.01] ; with a significant reduction of MND （2041± 363） nuclei/ram2 ： （3067±254） nuclei/mm^2 , P〈0. 011 in CAM group; MND was highly correlated to MAR1 （r =-0.73, P〈0.01） and to MAR2 （r=-0.86, P〈0.01）. Conclusion： Myocyte apoptosis may lead to progressive myocyte loss following coronary artery microthrombosis.