Liu Zhengxiang, Li Zhigang, Liu Xiaochun
Department of Cardiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030.
J Huazhong Univ Sci Technolog Med Sci. 2002;22(4):305-9. doi: 10.1007/BF02896771.
To observe the effect of ginsenoside Re on cardiomyocyte apoptosis and Bcl-2/Bax gene expression after ischemia (30 min) and reperfusion (6 h) in rats and to elucidate the possible mechanisms of ginsenoside Re on inhibition of cardiomyocyte apoptosis, the ischemia/reperfusion heart model was established by ligating the left anterior descending branch of coronary artery in Wistar rats. The apoptotic cardiomyocytes were confirmed by transmission electron microscopy and counted by in situ nick end labeling (TUNEL) method and light microscopy. The mRNA and protein expression of Bcl-2 and Bax genes were studied by in situ hybridization and immunohistochemical staining. Mean optical density (OD) value of the positive fields of mRNA and protein expression was quantitatively examined by image analysis system. The results were as follows: (1) The apoptotic cardiomyocytes were found in ischemic fields in the ischemia/reperfusion group and weren't observed in the sham-operation group by transmission electron microscopy; (2) The numbers of the apoptotic cells were 134.45 +/- 45.61/field in the ischemia/reperfusion group, and 90.66 +/- 19.22/field in the ginsenoside Re-treated group. The differences was significant between two groups (P < 0.01); (3) Gene expression of Bcl-2 and Bax were increased significantly in the ischemia/reperfusion group and ginsenoside Re-treated group when compared with the sham-operation group. There was no significant difference in the gene expression of Bcl-2 between the ginsenoside Re-treated group and ischemia/reperfusion group (P > 0.05), but gene expression of Bax was decreased significantly in the ginsenoside Re-treated group as compared with the ischemia/reperfusion group (P < 0.01). The ratio of Bcl-2/Bax was increased significantly in the ginsenoside Re-treated group when compared with the ischemia/reperfusion group and sham-operation group. These findings suggest that myocardial ischemia-reperfusion can induce cardiomyocyte apoptosis, and ginsenoside Re can significantly inhibit cardiomyocyte apoptosis induced by ischemia-reperfusion in rats. It is concluded that ginsenoside Re inhibits cardiomyocyte apoptosis by inhibiting expression of pro-apoptotic Bax gene and raising the ratio of Bcl-2/Bax.
为观察人参皂苷Re对大鼠心肌缺血（30分钟）及再灌注（6小时）后心肌细胞凋亡及Bcl-2/Bax基因表达的影响，并阐明人参皂苷Re抑制心肌细胞凋亡的可能机制，采用结扎Wistar大鼠冠状动脉左前降支的方法建立缺血/再灌注心脏模型。通过透射电镜确认凋亡心肌细胞，并采用原位缺口末端标记法（TUNEL）和光学显微镜进行计数。采用原位杂交和免疫组织化学染色法研究Bcl-2和Bax基因的mRNA及蛋白表达。应用图像分析系统对mRNA和蛋白表达阳性区域的平均光密度（OD）值进行定量检测。结果如下：（1）透射电镜观察发现，缺血/再灌注组缺血区域存在凋亡心肌细胞，假手术组未观察到；（2）缺血/再灌注组凋亡细胞数为134.45±45.61/视野，人参皂苷Re治疗组为90.66±19.22/视野。两组间差异有统计学意义（P<0.01）；（3）与假手术组相比，缺血/再灌注组及人参皂苷Re治疗组Bcl-2和Bax基因表达均显著增加。人参皂苷Re治疗组与缺血/再灌注组Bcl-2基因表达无显著差异（P>0.05），但人参皂苷Re治疗组Bax基因表达较缺血/再灌注组显著降低（P<0.01）。与缺血/再灌注组及假手术组相比，人参皂苷Re治疗组Bcl-2/Bax比值显著升高。这些结果提示，心肌缺血-再灌注可诱导心肌细胞凋亡，人参皂苷Re可显著抑制大鼠缺血-再灌注诱导的心肌细胞凋亡。结论为人参皂苷Re通过抑制促凋亡Bax基因表达及提高Bcl-2/Bax比值抑制心肌细胞凋亡。
