不同时期浅低温对大鼠脑缺血再灌注时谷氨酸、Bel—2和Bax水平的影响  

Effects of mild hypothermia performed at different times on levels of glutamate, Bcl-2 and Bax during global cerebral ischemia-repersusion in rats

作　　者：姚淑萍[1] 张山[1] 熊渤辉[1] 姚文瑜[1] 徐雪[1] 

机构地区：[1]河北医科大学第二医院麻醉科,石家庄市050000

出　　处：《中华麻醉学杂志》2010年第9期1105-1108,共4页Chinese Journal of Anesthesiology

基　　金：河北省引进留学人员资助项目[人社厅（2008）86号]

摘　　要：目的评价不同时期低温对大鼠脑缺血再灌注时脑组织谷氨酸、Bcl-2和Bax水平的影响。方法成年雄性sD大鼠24只，随机分为4组（n=6），A组、B组、C组和D组均采用四血管阻断20min的方法制备全脑缺血再灌注模型。B组、C组和D组均采用鼻咽腔降温的方法维持海马温度32．5～33．5℃1h，B组降温结束时进行缺血；C组缺血的同时开始降温；D组再灌注的同时开始降温，3组降温结束后开始复温。缺血和再灌注100min期间每隔10min收集一次海马CAl区微透析液，测定谷氨酸浓度，反映海马CA1区谷氨酸释放水平。再灌注3h时，取脑组织，测定海马CA1区Bcl-2和Bax的表达水平，并计算Bcl-2和Bax表达的比值（Bcl-2／Bax）。结果与A组比较，其他3组再灌注期间海马谷氨酸释放水平降低，Bcl-2表达上调，Bax表达下调，Bcl，2／Bax升高（P〈0．05）；与B组比较，C组海马Bcl-2表达下调，Bax表达上调，Bcl-2／Bax比值降低（P〈0．05）；与C组比较，D组再灌注期间海马谷氨酸释放水平升高，Bax表达上调，Bcl-2／Bax降低（P〈0．05）。结论降温实施越早减轻大鼠脑缺血再灌注损伤的效应越强。Objective To evaluate the effects of mild hypothermia performed at different times on the levels of glutamate, Bcl-2 and Bax during global cerebral isehemia-reperfsusion （I/R） in rats. Methods Twenty-four male SD rats weighing 230-270 g were randomly divided into 4 groups according to the time at which mild hypothermia was performed （ n = 6 each） ： group A, B, C and D. Global cerebral ischemia was produced by occlusion of 4 vessels （cauterization of bilateral vertebral arteries and occlusion of bilateral common carotid arteries） in the 4 groups. In group B, C and D, the nasopharyngeal temperature was reduced to 32.5-33.5 ℃ and maintained for 1 h. Ischemia was performed after termination of cooling in group B. While ischemia was performed, cooling was started in group C. While reperfusion was performed, cooling was started in group D. Rewarming was started after termination of cooling in group B, C and D. Samples of dialysate in hippocampal CA1 area were collected every 10 min during 100 min reperfusion for determination of glutanmte concentrations by high-performance capillary electrophoresis with laser-induced fluorescence detection （HPCE-LIF）. The brain tissues were taken at 3 h of reperfusion for determination of the expression of Bax and Bcl-2 in hippocampal CA1 area, and the ratio of Bcl-2/Bax was calculated. Results Compared with group A, the glutamate concentrations were significantly de- creased, the Bcl-2 expression was up-regulated, the Bax expression was down-regulated and the ratio of Bcl-2/Bax was increased in the other three groups （ P 〈 0.05）. Compared with group B, the Bcl-2 expression was significantly down-regulated, the Bax expression was up-regulated and the ratio of Bcl-2/Bax was decreased in group C （ P 〈0. 05）. The glutamate concentrations were significantly increased, the Bax expression was up-regulated and the ratio of Bcl-2/Bax was decreased in group D compared with group C （ P 〈 0.05）. Conclusion The earlier cooling is performed, the better the cere

关 键 词：低温 人工 再灌注损伤 脑 谷氨酸 Bcl相关蛋白质 BAX蛋白 

分 类 号：R285.5[医药卫生—中药学]