浅低温对大鼠全脑缺血再灌注酸敏感离子通道1a和2a表达的影响  

Effect of mild hypothermia on the expression of acid-sensing ion channels la and 2a following global cerebral ischemia-reperfusion in rats

作　　者：高玮[1] 曾秋婷[2] 程慧娴[2] 崔耀梅[2] 李茜[2] 孙茜[1] 段满林[2] 徐建国[2] 

机构地区：[1]徐州医学院江苏省麻醉学重点实验室,江苏省221002 [2]南京军区南京总医院麻醉科

出　　处：《中华医学杂志》2013年第7期546-549,共4页National Medical Journal of China

摘　　要：目的探讨浅低温对大鼠全脑缺血再灌注后酸敏感离子通道1a（ASIC1a）和2a（ASIC2a）的影响及在脑复苏作用中的潜在机制。方法95只雄性sD大鼠随机数字表分为以下5组（n=19）：假手术组（I）、模型组（Ⅱ）、浅低温组（Ⅲ）、PcTX1组（1V）、浅低温＋PcTX1组（V）。四血管阻塞法建立大鼠全脑缺血再灌注损伤模型，缺血15min，再灌注即刻Ⅳ组和V组侧脑室注射500ng／mlPcTXl6μl，其余组侧脑室注射等容量生理盐水。同时Ⅲ组和V组于再灌注15min内将直肠温度降至32～33℃，并维持6h，其余组维持直肠温度36～37℃。测定再灌注6h及24h海马ASIC1a和ASIC2a蛋白水平、再灌注24h海马ASIC1a和ASIC2amRNA表达水平；观察再灌注24h海马CA1区病理改变；以及测定再灌注72h大鼠脑含水量。结果与I组比，其余各组ASIC1amRNA和蛋白的表达差异无统计学意义（P〉0．05）；与I组比，其余各组ASIC2amRNA和蛋白的表达均增高（P〈0．05）；与Ⅱ组和Ⅳ组比，Ⅲ组和V组ASIC2amRNA和蛋白的表达增高（P〈0．05）；与再灌注6h相比，再灌注24hⅡ、Ⅲ、IV和V组ASIC2a蛋白表达均增高（P〈0．05）；与Ⅰ组比，Ⅱ、Ⅲ、Ⅳ和V组CA1区锥体细胞数均减少（P〈0．01）；与Ⅱ组比，Ⅲ、Ⅳ和V组CA1区锥体细胞数均增加（P〈0．01），尤以V组效果最明显（P〈0．01）；与I组比，Ⅱ、Ⅲ和Ⅳ组脑水含量均增加（P〈0．01）；与Ⅱ组比，Ⅲ、Ⅳ和V组脑水含量均降低（P〈0．01），V组降低最明显（P〈0．01）。结论浅低温减轻大鼠全脑缺血再灌注损伤可能与ASIC2amRNA和蛋白表达上调有关，且浅低温联合PcTX1对缺血脑组织的复苏具有协同作用。Objective To investigate the effects of mild hypothermia on the expression of ASICla and ASIC2a in the rat hippocampus following global cerebral ischemia-reperfusion, so as to speculate the underlying mechanisms of neuroresuscitation. Methods Ninety five male SD rats were randomly divided into five groups （n = 19） ：sham operation group（ I ）, model group（ H ） , mild hypothermia group（ Ⅲ ）, PcTX1 group（ 1V ）, mild hypothermia combined PcTX1 group （ V ）. Transient （ 15 min） global cerebral ischemia was induced by the four-vessel occlusion. PcTX1 （500 ng/ml） 6 were injected into lateral cerebral ventricle immediately after reperfusion in group IV and V, while the equal volume of normal saline was injected into lateral cerebral ventricle immediately after reperfusion in the other three groups. At the same time, mild hypothermia after reperfusion was performed and lasted for 6 hours in group DI and V, the rectal temperature was reduced to 32 -33 ℃ within 15 min, while it was maintained at 36 -37 ℃ by lamp in other three groups. Determination the expression of ASIC1 a and ASIC2a protein at 6 h and 24 h of reperfusion, and the expression of ASIC1 a and ASIC2a mRNA at 24 h of reperfusion. Observe the pathomorphological changes of hippocampal CA1 neurons at 24 h of reperfusion Detect the brain water content at 72 h of reperfusion. Results The difference in the expression of ASICla mRNA and protein among the groups was not changedsignificantly （P 〉 0. 05 ）. Compared with group I , the expression of ASIC2a mRNA and ASIC2a protein was up-regulated in other groups （P 〈 0. 05）. It was significantly higher in group HI and V than in group Ⅱand 1V （P 〈 0. 05）. Compared to 6 h of reperfusion, the expression of ASIC2a protein was higher in group Ⅱ , Ⅲ, IV and V respectively after 24 h of reperfusion. Compared to group I , the number of pyramidal cells in CAl region of hippocampus in group Ⅱ , Ⅲ, 1V and V were decreased at 24 h of reperfusion （P 〈0. 01 ）. Comp

关 键 词：低温 脑缺血 再灌注损伤 酸敏感离子通道 

分 类 号：R743[医药卫生—神经病学与精神病学]