犬全脑缺血后头部选择性浅低温对脑内源性神经保护的影响  

Effects of selective head mild hypothermia on endogenous neuroprotection in brain following global cerebral ischemia/reperfusion injury:experiment with dogs

作　　者：程智刚[1] 于鹏[1] 王云姣[1] 李靖怡[1] 黄菊芳[2] 郭曲练[1] 谭秀娟[1] 

机构地区：[1]中南大学湘雅医院临床麻醉学教研室,长沙410008 [2]中南大学湘雅医学院解剖学与神经生物学系

出　　处：《中华医学杂志》2007年第19期1318-1321,共4页National Medical Journal of China

摘　　要：目的研究犬全缺血后浅低温对脑内源性神经保护的影响。方法 15只健康杂种犬随机分为3组:手术对照组(A 组,n=4只),缺血再灌注组(B 组,n=5只),浅低温治疗组(C 组,n=6只)。A 组动物完成麻醉和手术后心脏不停跳观察8 h。B 组和 C 组动物心脏停跳18 min,心脏复苏成功后,B 组动物观察8 h,C 组动物接受浅低温[(34±0.5)℃]治疗。实验结束时开颅取右顶叶脑皮质供测超氧化物歧化酶(SOD)、谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)含量和免疫组织化学法显示小白蛋白(PV)和热休克蛋白70(HSP_(70))阳性神经元。结果 B 组动物脑内 GSH、GSH-Px、T-SOD、Mn-SOD、Cu-ZnSOD、PV 阳性神经元数量显著低于 A 组(P<0.05或 P<0.01),而 HSP_(70)-LI 阳性神经元数量明显高于 A 组[(15.6±3.7)vs(5.5±2.1),P<0.05]。C 组动物脑内 GSH、T-SOD、Cu-ZnSOD、PV 阳性神经元和 HSP_(70)-LI 阳性神经元数量明显高于 B 组 PV-I 神经元密度:(34.7±6.3)vs(23.8 5.3),P<0.05;HSP_(70)-LI 阳性神经元密度:(27.1±4.9)vs(15.6±3.7),P<0.05。结论脑内内源性神经保护作用增强可能是浅低温治疗脑缺血的机制之一。Objective To study the effects of selective head mild hypothermia on endogenous neuroprotection in brain following global cerebral ischemia/reperfusion. Methods Fifteen dogs were randomly divided into three groups, nonischemic control group （ Group A, n = 4）, undergoing thoracotomy without cerebral ischemia and general care for 8 hours thereafter; cerebral ischemia/reperfusion group （ Group B, n = 5 ） undergoing thoracotomy, clipping of the ascending aorta for 18 min, cardiac resuscitation, maintenance of respiration and circulation for 8 h ; and mild hypothermia group （ Group C, n = 6）, received selective head mild hypothermia, i.e. lowering the tympanic temperature to （34 ± 0. 5 ） ℃ for 8 hours after cerebral ischemia. The neurological function was assessed by Glasgow coma scale and Pittsburgh brain stem score. At the end of experiment, the dog brains were taken out to obtain the right parietal cerebral cortex. Immunohistechenmistry was used to detect the parvalbumin （PV） and HSP70. Xanthine oxidase method was used to detect the superoxide dismutase （SOD） activities： total SOD （T-SOD）, manganese SOD （Mn- SOD）, and copper-zinc SOD （Cu-ZnSOD）. Spectrophotometry was used to detect the activities of glutathion （GSH） and glutathione peroxidase （GSH-Px）. Results The comprehensive neurological score of Group C was 23.4 ± 1.5, significantly higher than that of Group B （ 18. 6 ± 1.0, P 〈 0. 05 ）. The cerebral cortex of Group A showed a lot of PV positive neurons, the density of PV-positive neurons decreased significantly in Group B （ P 〈 0. 05 ）, and the density of PV-positive neurons win Group C was significantly higher then that of Group B, however, still significantly lower than that of Group A （ both P 〈 0. 05 ）. The density of HSF70 -LI neurons of Group A was very low （ 5.5 ± 2. 1 ）, those of Groups B and C were significantly higher than that of Group A （ 15.6 ± 3.7 and 27. 1 ± 4. 9 respectively, P 〈 0. 05 or P 〈 0. 01 ）, that of Gr

关 键 词：脑缺血 低温 热休克蛋白类 小白蛋白 

分 类 号：R743[医药卫生—神经病学与精神病学]