地塞米松对布比卡因诱导小鼠神经元毒性的影响  

Effect of dexamethasone on toxicity of bupivacaine in murine neurons

作　　者：马蓉[1] 王晓辉[2] 彭培培[1] 刘莉[2] 丁正年[1] 

机构地区：[1]南京医科大学第一附属医院麻醉科,210029 [2]南京医科大学第一附属医院老年医学科,210029

出　　处：《中华麻醉学杂志》2009年第6期516-518,共3页Chinese Journal of Anesthesiology

基　　金：江苏省“六大人才高峰”基金（07-B-041）;江苏省科技厅自然科学基金（BK2007247）;江苏省自然科学基金（BK2008467）

摘　　要：目的探讨地塞米松对布比卡因诱导小鼠神经母细胞瘤株（N2a）细胞毒性的影响。方法N2a细胞悬液（10^5／ml）随机分为4组：对照组（C组）、布比卡因组（Bup组）、地塞米松组（Dex组）和地塞米松＋布比卡因组（Dex＋Bup组）。各组N2a细胞分别接种于24孔培养板（0．5ml／孔）和直径10cm的培养皿中（7ml／皿），每组24孔和4皿。C组不行干预；Bup组加入含900μmol／L布比卡因的MEM培养基500μl；Dex组加入含1μmol／L地塞米松的MEM培养基500μl；Dex＋Bup组加入含1μmol／L地塞米松的MEM培养基500μl孵育12h后加入布比卡因900μmol／L。于24孔板中孵育5h时，测定线粒体跨膜电位（△ψm）；于24孔板中孵育9h时观察细胞形态，并计算LDH释放率和细胞核固缩率；于培养皿中孵育5h时测定磷酸化蛋白激酶B（p-Akt）和磷酸化胞外信号调节激酶（p-ERKs）的表达。结果C组细胞多边形，胞体折光性强，突触伸展良好；Dex组细胞形态学与C组相似；Bup组细胞扁平，突触缩短或断裂，胞体折光性弱；Dex＋Bup组扁平细胞减少，突触缩短或断裂减少，胞体折光性略低。与C组比较，Bup组LDH释放率和细胞核固缩率升高，△ψm降低，p-ERKs和p-Akt表达下调，Dex＋Bup组细胞核固缩率升高，△ψm降低，p-ERK表达下调，p-AKt表达上调，Dex组p-ERKs和p-Akt表达上调（P〈0．01）。与Bup组比较，Dex＋Bup组LDH释放率和细胞核固缩率降低，△ψm增加，p—ERKs和p-Akt表达上调（P〈0．01）。结论地塞米松可减轻布比卡因诱导N2a细胞毒性，其机制可能与恢复线粒体膜电位、抑制Akt和ERKs脱磷酸化有关。Objective To investigate the effect of dexamethasone on the toxicity of bupivacaine in murine neurons. Methods Murine neuroblastoma cell line N2a was obtained from ATCC ceil bank （USA）. The ceils were cultured in 10% fetal cow serum/MEM culture medium and divided into 4 group .group Ⅰ control （Con） ; group Ⅱ bupivacaine （Bup）; group Ⅲ dexamethasone （Dex） and group Ⅳ Dex ＋ Bup. The culture medium contained bupivacaine 900 l.unol/L in group Bup and dexamethasone 1 μmol/L in group Dex respectively. In group Dex＋ Bup （Ⅳ） Bup was added to the culture medium with a final concentration of 900 μmol/L at 12 h after pretreatment with Dex 1 μmol/L. The cells were inoculated in 24 well plates （0.5 ml in each well, 24 wells in each group） and 10 cm culture dishes （7 ml in each dish, 4 dishes in each group）. The release rate of LDH was calculated and the morphology of the cells and nucleus condensation （by Hoechst 3334224 fluorescent staining） was detected at 9 h of incubation in 24 well plates. The mitochondrial transmembrane potential （by JC-1 assay） and phosphorylation of Akt and ERKs （by Western blot） were measured at 5 h of incubation in 24 well plates and in culture dishes respectively. Results Bupivacaine caused severe damage to the N2a cells as evidenced by increase in LDH release and nucleus condensation （apoptosis）, dephosphorylation of Akt and ERKs, decrease in mitochondrial transmembrane potential and severe morphological changes. Dexamethasone pretreatment significantly attenuated bupivacaine-induced neurotoxicity. Conclusion Dexamethasone can protect N2a cells from bupivacaine-induced neurotoxicity through stabilization of mitochondrial transmembrane potential and inhibition of dephosphorylation of Akt and ERKs.

关 键 词：地塞米松 布比卡因 神经元 毒性作用 

分 类 号：R96[医药卫生—药理学]