亚低温对新生大鼠缺氧缺血性脑损伤后脑组织Caspase-3的表达变化

目的探讨亚低温对新生大鼠缺氧缺血性脑损伤（HIBD）脑组织天冬氨酸特异酶切的半胱氨酸蛋白酶一3（Caspase3）的表达变化。方法将7日龄Wistar大鼠120只随机分为3组。假手术组、缺氧缺血性脑损伤（HIBD）模型组（肛温37℃）和亚低温治疗组（肛温33℃），每组各40只。每组根据处死的时间不同又分为5个亚组：6h组、12h组、24h组、48h组、72h组，每亚组各8只。采用免疫组化的方法测定Caspase-3的活性。结果HIBD组缺氧缺血侧大脑组织Caspase-3活性逐渐增高，48h达高蜂（caspase-3阳性细胞平均灰度值144．15±4．50），然后逐渐下降，72h后仍有明显增高；与HIBD模型组各时间点相比，亚低温组各时间点脑组织Caspase-3表达均明显降低（P〈0．01）。结论亚低温治疗可通过降低缺氧缺血后Caspase-3酶的活性，从而起到脑保护作用。

Effect of Mild Hypothemia on Caspase - 3 in Brain Tissue after Hypoxic ischemic Brain Damage in Neonatal Rats

Objective To explore the effect of mild hypothemia on easpase - 3 in brain tissue after hypoxic ischemic brain damage （HIBD） in neonatal rats. Methods A total of 120 seven- day - old Wistar rats were randomly assigned into three groups（n = 40 in each group） ： Sham - operated group,mild bypothermia group（rectal temperature 33 C） and HIBI） group（rectal temperature 37℃）. Then each group were divided into five subgroups （n=8 in each subgroup） based on different time points after HIBD （6 h,12 h,24 h, 48 h,72 h）. The expression of easpase - 3 in brain tissues was detected with immunohistochemistry. Results The expression of Caspase- 3 in brain tissues was found in normal thermia group at 6 bour,s after bypoxic- ischermJa brain damange, increased with time, reached peak at 48 hours, and reduced after that point. After 72 hours, the expression was slightly higher than that of sham- op- erative group. Expressions of Caspase - 3 in brain tissue at different time points were decreased significantly in mild hypotbermia groups（P〈0.01）. Conclusion Mild hypothermia could decrease the expression of Caspase - 3 in brain tissue after HIBD,which con tribute to the protection of brain tissue.