MAPK在弗司可林诱发的脊髓背角LTP中的作用

Role of MAPK in the induction of LTP of C-fiber-evoked field potentials in the spinal dorsal horn induced by Forskolin

目的探讨丝裂霉素活化蛋白激酶(MAPK)在弗司可林(Forskolin)诱发的脊髓背角长时程增强(LTP)中的作用。方法采用SD大鼠,常规细胞外记录技术记录脊髓背角腰膨大部位浅层C-纤维诱发电位。结果①弗司可林(100μmol/L)诱发的脊髓背角LTP为PKA的抑制剂H89(200μmol/L)所阻断;②MAPK的选择性抑制剂PD98059(100μmol/L)阻断弗司可林诱导的脊髓LTP;③NMDA受体抑制剂阻断弗司可林诱导的脊髓LTP。结论 MAPK参与弗司可林诱导的脊髓背角C-纤维诱发的LTP;弗司可林诱导的LTP可能是通过cAMP-PKA-MAPK信号途径起作用的。

Objective To evaluate the role of mitogen-activated protein kinase （MAPK） in the induction of spinal long-term potentiation （LTP） induced by Forskolin. Methods The C-fiber evoked field potentials were recorded at the superficial layers of the spinal dorsal horn at the lumbar enlargement. Results ① Forskolin （100μmol/L）-induced LTP of C-fiber evoked field potentials was blocked by H89 （a PKA inhibitor）. ② Specific inhibitor of MAPK PD98059 blocked the induction of spinal LTP by Forskolin. ③ The synaptic potentiation induced by Forskolin was blocked in the presence of either MK-801 or APV,inhibitors of NMDA receptor. Conclusions MAPK is involved in the induction of LTP of C-fiber evoked field potentials in the spinal dorsal horn by Forskolin. The Forskolin-induced effect might be mediated via the cAMP-PKA-MAPK signaling pathway.