大鼠缺血再灌注心肌细胞中Caspase-3和Bcl-2基因的表达

目的探讨缺血再灌注(IR)心肌细胞中Caspase-3和Bcl-2基因的动态表达。方法健康Wistar成年大鼠70只随机分为对照组10只,实验组60只,实验组再分为IR 2 h、4 h、8 h、12 h、24 h和48 h共6个亚组,每亚组10只。建立大鼠心肌IR模型,采用原位杂交、原位末端标记染色等技术检测IR后Caspase-3 mRNA和Bcl-2 mRNA的动态表达。结果凋亡细胞主要位于IR交界区,于IR12 h达高峰;坏死细胞主要位于IR梗死区。实验组IR交界区与梗死区Caspase-3 mRNA均于IR 2 h开始升高,且高于对照组(P<0.01),交界区于IR 12 h到24 h达峰值,与细胞凋亡发生的时间基本一致,梗死区于IR 8 h达峰值。实验组IR交界区和梗死区Bcl-2 mRNA自IR 2 h始呈持续低水平升高,在IR24 h后Caspase-3 mRNA开始下降时其表达仍持续升高;相同时相点IR交界区Bcl-2 mRNA的阳性率高于梗死区(P<0.05)。Caspase-3 mRNA、Bcl-2 mRNA和凋亡细胞的表达在交界区均比在梗死区活跃(P<0.05)。结论细胞凋亡是IR损伤发生的主要标志;Caspase-3和Bcl-2二者之间形成抗衡的网络调控构象,负责凋亡的促进和凋亡的抑制。

Expression of Caspase-3 and Bcl-2 genes in myocardial cells of rats with ischemia reperfusion

Objective To explore the expression of Caspase-3 and Bcl-2 genes in myocardial cells of rats with isehemia reperfusion（IR）. Methods A total of 70 healthy Wistar rats were randomly divided into control group（ n = 10） and experiment group （n = 60 ）, then the experiment group were observed at I R 2 h ,4 h, 8 h, 12 h ,24 h and 48 h, with 10 rats in each phase. The rat models of IR were established. Expressions of Caspase-3 mRNA and Bcl-2 mRNA were determined by the technique of in situ hybridization and TUNEL after IR. Results Apoptosis were mostly located at boundary area,and the peak value of apoptosis index was at IR 12 h,but necrosis at infarct area. Caspase-3 mRNA at both boundary area and infarct area in experiment group obviously increased after IR 2 h, and the value was higher than control group（ P 〈 0.01 ） , and its peak value was at IR 12 h to 24 h at boundary area,which conformed to the time of apoptosis;and its peak value was at IR 8 h at infarct area. Bel-2 mRNA at both boundary area and infarct area expressed lowerly, but it increased continually when Caspase-3 mRNA decreased after IR 24 h;Bcl-2 mRNA at boundary area were higher than at infarct area（ P 〈 0.05 ）. The expressions of Caspase-3 mRNA ,Bcl-2 mRNA and apoptosis at boundary area were more obvious than at infarct area （ P 〈 0.05 ）. Conclusion Myocardial apoptosis at boundary area is the main sign of injury after IR ; Caspase-3 and Bel-2 formed a kind of match of network, adjusting to promote or repress apoptosis.