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目的 :探讨多巴胺对ATP激活电流的调制作用。方法 :实验在培养的新生大鼠脊髓背根神经节细胞上进行 ,应用全细胞膜片钳技术记录出ATP和多巴胺激活的电流。结果 :在被检的DRG细胞中 ,有 6 2 % (39/ 6 3)的神经元对ATP和多巴胺都敏感。在预加 10 -8,10 -7,10 -6和 10 -5mol/L多巴胺后 ,ATP的激活电流分别增加到 139.7% ,141.5 % ,149.9% ,149.1% ;呈剂量依赖性。用D1的拮抗剂SCH - 2 3390能取消此增强作用 ;在电极中灌注H - 7(PKC ,PKA抑制剂 )也能取消此增强作用。结论 :多巴胺对ATP激活电流的增强作用是多巴胺作用于D1受体 ,通过胞内第二信使 ,使P2X受体通道复合体胞内磷酸化所致。
Objective: To investigate the modulatory effect of dopamine on ATP-activated currents. METHODS: Experiments were performed on cultured neonatal rat dorsal root ganglion neurons. ATP and dopamine-activated currents were recorded using whole-cell patch-clamp techniques. RESULTS: Sixty-two percent (39/6 3) of the neurons in the DRG cells tested were both sensitive to both ATP and dopamine. After pretreatment with 10 -8, 10 -7, 10 -6 and 10 -5 mol / L dopamine, the activation current of ATP increased to 139.7%, 141.5%, 149.9% and 149.1% respectively in a dose-dependent manner. D1 - antagonist SCH - 2 3390 abolished this enhancement; perfusion of H - 7 (PKC, PKA inhibitor) in the electrode also abolished this enhancement. CONCLUSION: The enhancing effect of dopamine on ATP-activated current is that dopamine acts on D1 receptor and causes intracellular phosphorylation of P2X receptor channel complex via intracellular second messenger.