【摘要】 目的 :探讨蛋白激酶C (PKC)在大鼠脊髓背角C -纤维诱发电位长时程增强 (LTP)的诱导和维持中的作用。方法 :细胞外记录技术在脊髓腰膨大部记录背角浅层神经元C -纤维诱发电位。结果 :(1)PKC的选择性抑制剂chelerythrine(2 0 0 μmol/L)或G 6 983(10 0 μmol/L)对脊髓背角C -纤维诱发电位的基础电位没有影响 ,但可完全阻断脊髓背角LTP的诱导。 (2 )Chelerythrine或G 6 983呈时间依赖性翻转脊髓背角LTP。在LTP诱导后 15min ,脊髓局部给予chelerythrine(2 0 0 μmol/L)后 ,LTP逐渐降低 ,于给药后 70min降至对照水平 ;而G 6 983(10 0 μmol/L)产生同chelerythrine相似的效应 ,在用药后 110min ,LTP降至对照水平。但同样浓度的chelerythrine或G 6 983在LTP诱导后 3h ,均不能翻转业已建立的LTP。结论 :PKC参与脊髓背角C -纤维诱发电位LTP的诱导和早期维持 ,而不影响晚期LTP的维持。更多还原

【Abstract】 AIM: The role of protein kinase C (PKC) in th e induction and maintenance of spinal long-term potentiation (LTP) was evaluated . METHODS: The C-fiber evoked field potentials were recorded at t he superficial layers of spinal dorsal horn at the lumbar enlargement. RESULTS: (i) Chelerythrine (200 μmol/L) or G 6983 (100 μ mol/L), a selective PKC inhibitor, completely blocked LTP induction. (ii) Chel eryt hrine or G 6983 reversed spinal LTP in a time-dependent manner. 15 min after L TP induction, chelerythrine (200 μmol/L) and G 6983 (100 μmol/L) depre ssed LTP to baseline in all tested rats. The same concentration of chelerythrine and G 6983, applied at 3 h after LTP induction, did not affect LTP. CONCLUSION: PKC in spinal dorsal horn may be crucial for the ind uction and the early-phase maintenance of LTP of C-fiber evoked field potentials .更多还原