脊髓背角长时程增强中CaMKⅡ磷酸化水平的变化  

Changes in phosphorylated level of CaMKⅡ in spinal dorsal horn during long-term potentiation

作　　者：信文君[1] 宫庆娟[1] 魏绪红[1] 张彤[1] 李永勇[1] 刘先国[1] 

机构地区：[1]中山大学中山医学院生理学教研室,广东广州510080

出　　处：《解剖学研究》2006年第4期247-250,共4页Anatomy Research

基　　金：国家自然科学基金资助项目(No.30200076;30370474)

摘　　要：目的探讨长时程增强诱导和维持过程中脊髓背角钙/钙调蛋白依赖性蛋白激酶Ⅱ(CaMKⅡ)磷酸化水平的变化。方法(1)细胞外记录脊髓腰膨大部背角浅层神经元C-纤维诱发电位;(2)免疫组化技术观察脊髓背角CaMKⅡ磷酸化水平的变化。结果(1)LTP30min、LTP3h脊髓背角CaMKⅡThr286的磷酸化水平明显高于对照组;(2)强直刺激前30min脊髓局部给予KN-93(CaMKⅡ选择性抑制剂,100μmol/L),LTP的诱导被完全阻断,CaMKⅡ磷酸化水平与对照组无明显差别;(3)强直刺激后30min给予KN-93,明显抑制LTP,CaMKⅡ的磷酸化水平也显著降低;(4)LTP3h后给予KN-93,LTP幅度和CaMKⅡ磷酸化水平与用药前相比,差异没有统计学意义。结论CaMKⅡ磷酸化可能在脊髓背角C-纤维诱发电位长时程增强诱导和早期维持中发挥重要作用。Objective To investigate changes in phosphorylated level of calcium/calmodulin-dependent protein kinase Ⅱ （CaMKⅡ） in spinal dorsal horn during long-term potentiation （LTP） induction and maintenance. Methods The C-fiber evoked field potentials were recorded at the superficial layers of spinal dorsal horn at the lumbar enlargement. The phosphorylated level of CaMK Ⅱ in spinal dorsal horn was observed with immunohistochemistry technique. Results The phosphorylated level of CaMK Ⅱ Thr286 markedly increased at 30 min and 3 h after the establishment of LTP. LTP was completely blocked and the phosphorylated level of CaMK Ⅱ was not different from that of the control by spinal application of KN-93 （a selective CaMK Ⅱ inhibitor, 100 μmol/L） at 30 win prior to tetanus. Spinal application of KN-93 at 30 min after tetanic stimulation significantly depressed LTP and the level of phosphorylated CaMK Ⅱ. Spinal application of KN-93 at 3 h after LTP, there were no obvious changes in LTP and the level of phosphorylated CaMK Ⅱ. Conclusion The phosphorylafion of CaMK Ⅱ may play an important role in the induction and the early-phase maintenance of LTP of C-fiber evoked field potentials in spinal dorsal horn.

关 键 词：长时程增强 钙/钙调蛋白依赖性蛋白激酶Ⅱ 脊髓背角 

分 类 号：R33[医药卫生—人体生理学]