氯胺酮对大鼠脊髓背角星形胶质细胞的保护机制  

Mechanism of protective effect of ketamine on primary astrocytal cultures in rats spinal cord dorsal horn

作　　者：李清[1] 向勇[1] 刘菊英[1] 王贤裕[1] 

机构地区：[1]湖北省十堰市郧阳医学院附属太和医院麻醉科,442000

出　　处：《临床麻醉学杂志》2007年第4期317-319,共3页Journal of Clinical Anesthesiology

基　　金：湖北省教育厅科学技术研究项目(B200524003)

摘　　要：目的探讨氯胺酮对N-甲基-D-天冬氨酸(NMDA)诱导的大鼠脊髓背角星形胶质细胞损伤的保护机制。方法取新生2～3dWistar大鼠40只T12～L5脊髓背角星形胶质细胞,原代纯化培养3周。将细胞随机分六组:NMDA组(N组),氯胺酮组(K组)、NMDA加不同浓度氯胺酮组(标记为NK1～NK3组),对照组(C组)。加药后培养30min或24h取各组细胞检测超氧化物岐化酶(SOD)活性和丙二醛(MDA)含量,免疫细胞化学观察Bcl-2/Bax表达,流式细胞仪检测星形胶质细胞凋亡率和胞内游离钙浓度([Ca2+]i)。结果与C组比较,N组细胞发生大量凋亡(P<0.01),Bax强阳性表达,Bcl-2阴性表达,SOD活性显著降低(P<0.01),MDA含量明显增加(P<0.01),[Ca2+]i显著升高(P<0.01)。与N组比较,NK2、NK3组细胞凋亡明显减少(P<0.05或P<0.01),Bcl-2阳性表达,Bax阴性表达,[Ca2+]i低(P<0.05或P<0.01),SOD活性增加(P<0.01),MDA含量低(P<0.01)。结论氯胺酮抑制激活的背角星形胶质细胞内Ca2+超载,增强Bcl-2蛋白表达,抑制NMDA诱导的细胞凋亡,并增强抗氧化酶活性,抑制脂质过氧化反应引起的细胞损伤。Objective To investigate the mechanism of protective effect of ketamine on the primary astrocytal cells of rats spinal cord dorsal horn. Methods The cells were derived from T12-L5 spinal cord dorsal horn of 2-3 days old Wistar rats. After primary purification and culture for three weeks, the cells were treated with sham wash with Hanks solution （group C）, NMDA 125μmol/L （group N）, ketamine 100μmol/L （group K）, or NMDA 125μmol/L plus ketamine at 10, 50 or 100 μmol/L （group NK1, NK2, NK3 ）. At 30 min and 24 h of culture, MDA and SOD were measured,the expressions of Bcl-2 and Bax were detected with immunostaining,and the apoptosis and [Ca^2＋ ]i were analyzed with flow cytometer. Results Apoptotic cells death and the [Ca^2＋]i were significantly increased in group N compared with those in group C （P〈0.01）, the contents of MDA were significantly increased and the activity of SOD was markedly attenuated in group N compared with those in group C（P〈0.01）. Bax expression was positive but the expression of Bcl-2 was negative in group N. The apoptotic astrocytes and the [Ca^2＋ ]i were lower （P〈0.05）, the contents of MDA were significantly lower and the activity of SOD significantly increased in the NK2 group than those in group N （P〈0.01）. The expression of Bcl-2 was positive and Bax expression was negative in group NK2. The apoptotic astrocytes and the [Ca^2＋ ]i were significantly lower（P〈0.01）, the contents of MDA were significantly lower and the activity of SOD significantly higher in group NK3 than those in group N （P〈0.01）, The expression of Bcl-2 was positive and the Bax expression was negative in group NK3. No effect of ketamine itself at 100μmol/L was found. Conclusion The mecharilm of ketamine reducing astrocytes injury of spinal cord dorsal horn may involve the inhibition of intracellular Ca^2＋ overload, the increase of Bcl-2 expression, the decrease of Bax expression, the attenuation of oxygen free radcial and increase of antioxidase activity.

关 键 词：氯胺酮 脊髓背角 星形胶质细胞 损伤 

分 类 号：R614[医药卫生—麻醉学]