亚低温3 h可抑制新生大鼠缺氧缺血性脑细胞凋亡的影响

实验建立缺氧缺血性脑损伤新生大鼠模型，于缺血缺氧后立即采用31 ℃亚低温分别持续3，6，15 h进行全身干预，原位末端标记技术标记显示大鼠大脑皮质、海马、室周白质的凋亡细胞数减少，免疫组织化学法检测的细胞凋亡相关蛋白bcl-2和细胞周期调节相关蛋白p16表达降低，综合比较全部结果数据显示，且以亚低温干预3 h细胞凋亡抑制效果最佳，其次是亚低温干预6 h，而亚低温干预15 h可出现大脑皮质神经元细胞数降低的不良反应。结果证实，31 ℃亚低温干预可通过抑制细胞凋亡的方式对缺氧缺血性脑损伤组织起保护作用，3 h为最佳干预时间。

Hypothermic intervention for 3 hours inhibits apoptosis in neonatal rats with hypoxic-ischemic brain damage

A neonatal rat model of hypoxic-ischemic brain damage was designed and implemented in this study. Rats were subjected to hypothermia at 31°C immediately following hypoxia-ischemia for either 3, 6 or 15 hours. TdT-mediated dUTP nick end labeling demonstrated that the number of apoptotic cells was reduced in the rat cerebral cortex, hippocampus and periventricular white matter following hypothermia. Immunohistochemistry revealed that Bcl-2 and p16 expression were decreased. Inhibition of apoptosis was greatest with the 3 hour hypothermic treatment, followed by hypothermia for 6 hours. In contrast, hypothermia for 15 hours led to a decrease in neuronal number in the cerebral cortex. The results demonstrate that hypothermic intervention at 31°C protects brain tissue against hypoxic-ischemic brain damage by inhibiting apoptosis, and that the optimal length of treatment is 3 hours.