多巴胺对大鼠脊髓背根神经节神经元ATP—激活电流的调制作用  

Modulation by Dopamine of ATP Receptor Function in the Membrane of Rat Dorsal Root Ganglion Neurons

作　　者：李国华[1] 郭锐[1] 冯桂香[1] 李莉[1] 唐核心[2] 李之望[3] 

机构地区：[1]郧阳医学院机能实验室,湖北十堰442000 [2]郧阳医学院儿科教研室,湖北十堰442000 [3]华中科技大学同济医学院神经生物学系

出　　处：《郧阳医学院学报》2003年第4期203-206,218,共5页Journal of Yunyang Medical College

基　　金：国家自然科学基金 (No .39970 2 4 0 );湖北省教育厅研究基金 (2 0 0 2X96 )资助项目

摘　　要：目的 :研究多巴胺 (DA)对ATP -激活电流 (IATP)的调制作用。方法 :在大鼠新鲜分离的DRG神经元标本上应用全细胞膜片钳技术 ,记录DA对IATP的影响。结果 :大部分受检细胞 (89.5 % ,77/86 )对ATP敏感 ,10 -6～ 10 -3 mol/LATP可引起剂量依赖性呈明显去敏感的内向电流。在此 77个细胞中 ,预加DA对IATP的影响如下 :在 5 0 .6 % (39/77)的细胞产生抑制作用 ,2 8.6 % (2 2 /77)的细胞产生增强作用 ,其余的无明显作用 (2 0 .8% ,16 /77)。在浓度 10 -7～ 10 -3 mol/L范围DA对IATP的抑制或增强作用依赖于多巴胺的浓度。胞内透析GDP - β -s上述抑制或增强作用可完全被取消。结论 :DA对IATP的抑制作用可能是由于多巴胺受体激活后经G蛋白偶联使ATP(P2X)Objective The purpose of the present study is to explore whether Dopamine modulates the response mediated by ATP(P2X) receptors. Methods Experiments were performed on neurons freshly isolated from rat DRG using whole-cell patch clamp techniques. Results The majority of the neurons examined were responsive to ATP (89.5%,77/86) in the concentration range from 10 -6 to 10 -3 mol/L with an inward current showing obvious desensitization. In the 77 ATP-sensitive cells, preapplication of Dopamine for 30 seconds potentiated (28.6%, 22/77) or attenuated (50.6%, 39/77) I ATP in diverse subsets of cells, except in a small proportion of the cells it had no effect (20.8%, 16/77). Enhancive and inhibitory effects of Dopamine(10 -7～10 -3 mol/L) were dose dependent. By intracellular dialysis of GDP-β-s enhancive and inhibitory effects of Dopamine could be completely abolished. Conclusion Tthese modulation might be outcomes of the phosphorylation of ATP(P2X) receptor resulting from intracellular signal transduction.

关 键 词：多巴胺 大鼠 脊髓背根神经节 神经元ATP-激活电流 调制作用 

分 类 号：R965[医药卫生—药理学]