摘要
目的 探讨一种在天冬氨酸残基后进行裂解的半胱氨酸蛋白酶caspase 3 (cysteinproteasecleavingafteranaspresidue ,caspase 3 ) ;在全脑缺血 2 0min再灌注大鼠脑海马神经元凋亡中的作用。方法 雄性Wistar大鼠 182只 ,体质量(2 2 0± 2 0 )g ,分为对照组 (14只 )、缺血组 (84只 )和Ac DEVD CHO治疗组 (84只 ) ,后两组设立 8、2 4、48、72、12 0、168h 6个时相点。按Pulsinelli等的方法制作大鼠全脑缺血 2 0min再灌注模型 ,别于再灌注后上述 6个时相点处死取海马组织 ,对照组施行麻醉及手术 ,但不缺血 ,观察 72h后活杀取海马组织 ,分别测定海马组织胞质 (S 10 0 )中caspase 3活性及海马区神经元凋亡情况 ,分析caspase 3活性与海马区神经元凋亡的关系。结果 ①海马组织胞质中caspase 3活性在对照组中为 0 ,缺血再灌注后酶活性随时间的推移逐渐升高 ,至 12 0h达最高点 ,168h则有所下降 ;Ac DEVD CHO治疗后并不能完全抑制酶的活性 ,但显著降低了各时相点酶的活性 (8hP >0 0 5 ,2 4～ 12 0hP <0 .0 1,168hP <0 .0 5 ) ;②对照组海马中偶见凋亡细胞 ,缺血再灌注 8h凋亡细胞无明显增加 (P >0 .0 5 ) ,2 4h凋亡细胞明显增加 ,12 0h达峰值 ,168h有所减少 ,但 2 4～ 168h各时相点凋亡细胞数均明显多于对照组
Objective To investigate the roles of Caspase 3 in neuron apoptosis following cerebral ischemia/reperfusion in the rat hippocampus. Methods A model of rats with global ischemia induced by occlusion of the four vessels according to the method by Pulsinelli et al was used in this study. A total of 182 Wistar rats [(220±20) g] were divided randomly into three groups: control group ( n =14), cerebral ischemia group ( n =84), and cerebral ischemia group treated with acetyl asp glu val asp aldehyde (Ac DEVD CHO, n =84). Time points for observation included 8, 24, 48, 72, 120, and 168 h in the latter two groups. Caspase 3 activity in cytosolic extracts (S 100) of hippocampus and apoptotic neurons in hippocampus following cerebral ischemia/reperfusion were observed at the above mentioned time points, respectively. Results (1) No caspase 3 activity was detected in S 100 from the control group. In S 100 from the ischemia group, weak caspase 3 activity was detected at 8 h, but it increased gradually and peaked at 120 h, and then decreased apparently at 168 h after reperfusion. After treatment with Ac DEVD CHO following cerebral ischemia/ reperfusion, caspase 3 activity was inhibited to some extent at each time point. (2) Apoptotic cells were occasionally observed in hippocampus in the control group, but the apoptotic cells increased apparently at 24 h, peaked at 120 h, and decreased a few at 168 h after reperfusion in ischemia group. After treatment with Ac DEVD CHO following cerebral ischemia/reperfusion, apoptosis decreased to some extent at each time point (except 8 h following cerebral ischemia/ reperfusion). (3) Caspase 3 activity in S 100 from hippocampus was positively correlated with apoptotic neurons in hippocampus following cerebral ischemia/reperfusion at each time point ( r =0.9356 in ischemia group, r =0.980 0 in treatment group). Conclusion Caspase 3 may be one of the key causes resulting in neuron apoptosis in rat hippocampus after cerebral ischemia/reperfusion. It may play an important role in ischemia reperfusion brain injury.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2004年第14期1245-1247,共3页
Journal of Third Military Medical University
