摘要
目的 探讨亚低温在不同时间窗对实验性脑梗死氧自由基的影响。方法 将 110只 SD大鼠随机分成手术组和假手术组 ;手术组又分为亚低温组和常温组 ,再各分为手术后 0 h、2 h、4 h、6 h、7h、8h、9h、10 h、11h、12 h亚组 ;假手术组分为常温组和亚低温组 ;每组均 5只。手术组制备成左侧颈动脉近端栓塞的永久性缺血模型 ,假手术组只暴露左颈动脉不栓塞颈动脉。亚低温各亚组将肛温控制在 31.4℃左右 ,维持 12 h;然后处死 ,分离栓塞侧的大脑皮层 ,制备成均浆 ,分别测定一氧化氮 (NO)浓度、超氧化歧酶 (SOD)活性及丙二醛 (MDA)含量。结果 (1)假手术组左、右侧大脑皮质 NO、SOD、MDA含量比较无显著差异 (P>0 .0 5 ) ;(2 )亚低温 0～ 9h亚组 SOD含量较常温组各组增高 ,而 NO、MDA含量除 12 h亚低温亚组均较常温组显著降低 (P<0 .0 1或 P<0 .0 5 ) ;(3)亚低温 0～ 10 h亚组 NO浓度和 MDA含量明显低于 12 h亚组 (P<0 .0 1或 P<0 .0 5 ) ;(4 )亚低温 8h及 8h前各亚组 SOD活性较 12 h亚组显著增高 (P<0 .0 5或 P<0 .0 1)。结论 亚低温在一定的时间内可以通过抑制自由基的产生和促进其清除而发挥脑保护作用 ,但是对不同的因素影响的时间窗并不一致。
Objective To explore the effect of mild hypothermia on oxygen free radicals(OFR) following the experimental ischemic brain at defined time window. Methods 110 Sprague-Dawley(SD) rats were randomly divided into 3 groups:normothermia ischemia group,mild hypothermia ischemia group and sham-operated control group. Normothermia and mild hypothermia ischemia group were then divided into 10 subgroups(0h,2h,4h,6h,7h,8h,9h,10h,11h,12h) respectively sham-operated control group was then divided into normothermia and mild hypothermia subgroup,each subgroup contained 5 rats. In ischemia group,after the left middle cerebral artery occluded(LMCAO) using the suture occlusion technique,the rats were exposed to normothermia or mild hypothermia treatment(33+/-1.0℃) at defined time window. The rats in the control group were also exposed to normothermia or mild hypothermia,12 hours after,the rats were killed. The ischemia brain tissues were separated and the nitric oxide(NO),superoxide dismutase(SOD) and malonyldialdehyde(MDA) activities were assayed. Results (1) The levels of SOD in 0h-9h mild hypothermic treatment subgroups(MHTS) were siganificantly higher than those in all normothermia treatment subgroups(NTS) (P<(0.01) or P<(0.05)). (2)The levels of NO and MDA in MHTS (except for the 12h subgroup) were much lower than that in NTS (P<(0.01) or P<(0.05));(3)The SOD activities in some of the MHTS (0h,2h,4h,6h,7h and 8h subgroups) were significantly higher than that in the 12h MHTS(P<(0.01) or P<(0.05));the levels of NO and MDA in the 0h-10h MHTS were much lower than in the 12h MHTS (P<(0.01) or P<(0.05)). Conclusion It is known that oxygen free radicals(OFR) play an important role in the pathophysiological processes of cerebral ischemia. The mild hypothermia treatment in proper time may decrease the OFR and protect neurons against hypoxia,but the threapeutical time windows of mild hypothermia treatment are not the same to different factions in the ischemia brain tissues.
出处
《中风与神经疾病杂志》
CAS
CSCD
北大核心
2004年第5期415-417,共3页
Journal of Apoplexy and Nervous Diseases
