亚低温对细胞凋亡及凋亡相关基因表达影响的实验研究

Effect of hypothermia on apoptosis and expression of bax gene

目的 研究亚低温对新生鼠缺氧缺血性脑损伤细胞凋亡及凋亡相关基因表达的影响。方法 7日龄大鼠行左侧颈总动脉结扎后吸入 8%氧气 2h,制成缺氧缺血性脑损伤模型。动物随机分成三组 :假手术组 (C组 ) ,缺氧缺血正常温度组 (HI组 ) ,缺氧缺血后 30min亚低温治疗组。应用原位缺口末端标记 (TUNEL)检测凋亡细胞 ,用免疫组化SABC法检测表达bax基因阳性细胞数。结果 30min后给予亚低温组凋亡细胞及表达bax基因细胞数明显少于HI组 ,差异有显著意义 (P <0 0 1)。结论 亚低温可以通过抑制细胞凋亡 ,抑制凋亡相关基因的表达等机制发挥对缺氧缺血性脑损伤的保护作用。

The aim of this study is to examine the effect of mild hypothermia on apoptosis and expression of bax gene after hypoxia-ischemic brain damage(HIBD).Methods: The HIBD model was produced in the traditional model of neonatal hypoxia-ischemio (HI) which subjected 7-old-day Wistar rats to unilateral carotid artery ligation followed by an hypoxic(8%oxyger)episode of 2 hours duration.The rats were divided into three groups randomly,Group Ⅰ:sham-operated,Group Ⅱ:No treatment was applied to animal after hypoxic-ischemic onset,Group Ⅲ:4 hours of hypothermia was applied to animal at 30 minutes after the hipoxic-ischemic onset.Apoptosis was observed by terminal deoxynucleotidy1 transferase mediated dUTP-biotin nick end labelling(TUNEL)staining,expression of bax gene was evalued by immunohistochemical technique.Results: The number of apoptosis and expression bax gene cells of group Ⅲ was significantly lower than group Ⅱ(P<0 01).Conclusions:These results demonstrated that hypothermia prevented hypxic-ischemic brain damage by suppressing the apoptosis of cells and the espression of bax gene.