轻度低温对不全性兔脑缺血模型的保护

Mild hypothermia protects rabbit's brain from acute incomplete ischemia

目的观察轻度低温对缺血性兔脑组织的影响，了解是否对缺血性脑损伤具有保护作用，以及本实验采用的自行设计的急性不全性脑缺血模型的实用性。方法夹闭双颈总动脉结扎右椎动脉头高尾低直立位，制作脑缺血模型，松开双颈总动脉，体位平置形成缺血后再灌注，观察轻度低温在缺血发生前后脑电图、脑血流图、病理组织学的变化，测定脑组织中兴奋性氨基酸的含量。结果轻度低温治疗组兔脑电图的频率及波幅恢复率明显较对照组高。脑组织匀浆中谷氨酸（Ｇｌｕ）、天门冬氨酸（Ａｓｐ）的含量，轻度低温组高于正常体温组。脑血流图中反应脑干供血情况的枕－乳导联的频率波幅下降率明显低于反应前脑情况的额－乳导联（Ｐ＜０．０１）。结论轻度低温可减轻缺血及再灌注对脑组织的损害，促进脑电图的恢复，机理之一可能是阻止细胞内兴奋性氨基酸的过量释放。

Objective We want to know if mild hypothermia improves the brain's function destroyed by acute incomplete ischemia and to find if the new model is useful.Methods We successfully designed a model of acute incomplete ischemia of brain of rabbits,observed the effects of mild hypothermia on the changes of electroencephalograph(EEG),rheoencephalogram and pathomorphism between preand postischemia,and the differentiation in the excited amino acid (EAA) contain in hippocampus between hypothermia group and control group.Results We found that mild hypothermia could minify the impairing of pathomorphism in brain result from ischemia and reperfusion,made EEG to be normal,held back excited amino acid excessively releasing.Conclusion Mild hypothermia could protect model's brain from ischemia and reperfusion,one of the reasons may be holding back excited amino acid excessively releasing,and the new model is useful and convenient.