海马PKMζ/KCC2通路在异丙酚后处理对脑缺血再灌注大鼠长时程脑保护效应中的作用  

Role of hippocampal PKMζ/KCC2 pathway in propofol postconditioning-induced long-term cerebral protection following cerebral ischemia-reperfusion in rats

作　　者：刘书颖 王海云[1] 王国林[2] 王红柏[2] 朱敏[2] 

机构地区：[1]天津医科大学三中心临床学院天津市第三中心医院麻醉科,300170 [2]天津医科大学总医院麻醉科天津市麻醉学研究所

出　　处：《中华麻醉学杂志》2015年第9期1054-1056,共3页Chinese Journal of Anesthesiology

基　　金：国家自然科学基金（81071059,81571054,8100984）

摘　　要：目的 探讨海马蛋白激酶Mζ（PKMζ）/钾离子-氯离子共转运体2（KCC2）通路在异丙酚后处理对脑缺血再灌注大鼠长时程脑保护效应中的作用.方法 成年雄性SD大鼠60只,体重250～ 280 g,采用随机数字表法分为5组（n=12）：假手术组（S组）、脑缺血再灌注组（I/R组）和异丙酚后处理组（P组）、PKMζ抑制剂ZIP＋脑缺血再灌注组（Z＋I/R组）和ZIP＋异丙酚后处理组（Z＋P组）.采用大脑中动脉栓塞法制备脑缺血再灌注损伤模型.P组和Z＋P组于再灌注即刻静脉输注异丙酚20 mg·kg-1·h-12h,I/R组和Z＋I/R组给予等容量生理盐水2h.Z＋P组和Z＋I/R组于再灌注前15 min分别静脉注射ZIP 0.5μmol/L.于再灌注28 d时行改良神经行为学评分（mNSS评分）.行为学测试结束后,取海马组织,采用免疫荧光染色法计数CA1区GABA中间神经元GAD67/KCC2阳性神经元,采用Western blot法测定海马PKMζ和磷酸化KCC2（p-KCC2）的表达水平.结果 与S组比较,I/R组、P组和Z＋P组mNSS评分升高,海马GAD67/KCC2阳性神经元计数降低,PKMζ和p-KCC2表达下调（P＜0.05）;与I/R组比较,P组mNSS评分降低,海马GAD67/KCC2阳性神经元计数升高,PKMζ和p-KCC2表达上调,Z＋I/R组mNSS评分升高,海马GAD67/KCC2阳性神经元计数降低,PKMζ和p-KCC2表达下调（P＜0.05）;与P组比较,Z＋P组mNSS评分升高,海马GAD67/KCC2阳性神经元计数降低,PKMζ和p-KCC2表达下调（P＜0.05）.结论 异丙酚后处理对脑缺血再灌注大鼠长时程脑保护效应的机制可能与激活海马PKMζ/ KCC2通路有关.Objective To investigate the role of hippocampal protein kinase Mζ （PKMζ）/potassium-chloride cotransporter-2 （KCC2） pathway in propofol postconditioning-induced long-term cerebral protection following cerebral ischemia-reperfusion （I/R） in rats.Methods Sixty adult male Sprague-Dawley rats, weighing 250-280 g, were randomly divided into 5 groups （n =12 each）： sham operation group （group S）, cerebral I/R group （group I/R）, propofol post-conditioning group （group P） , PKMζ inhibitor ZIP＋cerebral I/R group （group Z＋I/R） , and ZIP ＋ propofol postconditioning group （group Z ＋ P）.Cerebral ischemia was induced by 1 h middle cerebral artery occlusion, followed by reperfusion in anesthetized rats.Propofol 20 mg · kg-1 · h-1was intravenously infused for 2 h in P and Z＋P groups, and the equal volume of normal saline was given for 2 h in I/R and Z＋I/R groups.In Z＋P and Z＋ I/R groups, ZIP 0.5 μmol/L was injected intravenously at 15 min before reperfusion.Modified Neurological Severity Score （mNSS） was assessed at 28 days of reperfusion.After the end of behavioral tests, the hippocampi were removed for determination of GABAergic interneurons GAD67/KCC2 positive neuron count in the hippocampal CA1 region （by using immunofluorescent staining）, and PKMζ and phosphorylated KCC2 （p-KCC2） expression （by Western blot）.Results Compared with group S, mNSS was significantly increased, GAD67/KCC2 positive neuron count was decreased, and the expression of PKMζ and p-KCC2 was down-regulated in I/R, P and Z＋P groups （P〈0.05）.Compared with group I/R, mNSS was significantly decreased, GAD67/KCC2 positive neuron count was increased, and the expression of PKMζ and p-KCC2 was up-regulated in group P, and mNSS was significantly increased, GAD67/KCC2 positive neuron count was decreased, and the expression of PKMζ and p-KCC2 was down-regulated in group Z＋I/R （P〈0.05）.Compared with group P, mNSS was significantly increased, GAD67/KCC2 positive neuron count

关 键 词：二异丙酚 缺血后处理 协同转运子 再灌注损伤 脑 海马 

分 类 号：R614[医药卫生—麻醉学]