亚低温对脑出血大鼠神经细胞凋亡及神经功能缺损的影响

目的 研究延迟性亚低温对大鼠脑出血后神经细胞凋亡及神经功能缺损的动态影响.方法 将大鼠随机分为正常组(N),假手术组(S),脑出血组(M),延迟12h亚低温组(HT12)和延迟24h亚低温组(HT24).应用立体定向技术将Ⅳ型胶原酶注人大鼠尾壳核制作脑出血模型,模型制备后于12h及24h点将大鼠放入冷室降温,维持肛温在(33±1)℃,均持续12h,各组在模型制作后12h、24h、36h、3d、7d记录大鼠神经功能缺损评分及死亡率.大鼠脑组织做HE染色及TUNEL染色,流式细胞技术观察神经细胞凋亡数目的变化.结果 亚低温(HT12,HT24)可减少脑出血后大鼠各时间点的TUNEL染色的阳性细胞数(P＜0.05);与模型组相比,3d时亚低温组( HT12,HT24)神经细胞凋亡率及大鼠7d的死亡率明显降低(P＜0.05),差别有统计学意义;延迟24h的亚低温可降低大鼠7d的NDS评分(P＜0.05),而12h的延迟治疗无此作用(P＞0.05).结论 延迟的亚低温治疗可减少大鼠脑出血后神经细胞的凋亡,降低死亡率,发挥脑保护作用.

Effects of delayed hypothermia on apoptosis of neurocytes and neurological impairs after intracerebral hemorrhage in rats

Objective To investigate the effects of delayed hypothermia on apoptosis of neurocytes and neurological impairs after intracerebral hemorrhage in rats.Methods Adult male Sprague-Dawley(SD)rats were randomly divided into five groups:NORMAL group(N),SHAM group(S),MODEL(M)group,delayed 12h moderate hypothermia group(HT12)and delayed 24h hypothermia group(HT24).Moderate hypothermia(33±1)℃ was initiated after 12h or 24h respectively,lasting for 12h.Neurological Deficit Scale(NDS)and rates of mortality were studied at different time points.HE,TUNEL and FCM were used to evaluate the apoptosis of neurocytes.Results Delayed hypothermia(HT12 and HT24)could effectively decrease TUNEL positive cells at all time points(P<0.05)and the cell apoptosis rates on 3d by FCM method,same consequences were also got in mortality rates of rats after 7d(P<0.05).In addition,24h delayed hypothermia could decrease NDS of rats on 7d significantly(P<0.05),except for 12h delayed cooling treatment.Conclusion Delayed moderate hypothermia provides effective brain protection by decreasing nerve cell apoptosis.