Two signal transduction mechanisms of substance P-induced depolarization in locus coeruleus neurons.
Two signal transduction mechanisms of substance P-induced depolarization in locus coeruleus neurons.
复制标题
P物质诱导蓝斑神经元去极化的两种信号转导机制。
DOI：
10.1111/j.1460-9568.1993.tb00973.x
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Nakajima,Y
中科院分区：
文献类型：
--
作者：
Koyano,K;Velimirovic,BM;Grigg,JJ;Nakajima,S;Nakajima,Y
应用全细胞膜片钳技术研究了P物质对培养的大鼠蓝斑神经元的作用。在某些细胞中，P物质产生的K电导下降，表现出内向整流特性。在其他细胞中，P物质产生初始内向电流，伴随着电导增加。其余细胞显示出上述两种反应的混合反应。在抑制电压门控Ca和K电导后，测量初始内向电流的反转电位表明，这是由非选择性离子电导的增加引起的。在260 μM GTPγS负载的细胞中，P物质使K电导不可逆地降低，但仍能记录到初始内向电流，提示前者由G蛋白介导，而后者可能由不同的信号转导机制激活。最初的内向电流不能通过外部应用高浓度的河豚毒素、d‐tubocurarine或阿米洛利消除。它也不受细胞内应用环GMP或环AMP的影响。
Effects of substance P on cultured neurons of the locus coeruleus of the rat were studied using the whole‐cell patch clamp technique. In some cells substance P produced a decrease in a K conductance which showed an inwardly rectifying property. In other cells substance P produced an initial inward current which was accompanied by a conductance increase. The rest of the cells showed responses which were mixtures of the above two responses. The measurement of the reversal potential of the initial inward current after suppressing the voltage‐gated Ca and K conductances suggests that it is caused by an increase in a non‐selective ionic conductance. In cells loaded with 260 μM GTPγS, application of substance P produced an irreversible reduction of the K conductance, while the initial inward current could still be recorded, suggesting that the former is mediated by a G protein, whereas the latter may be activated by a different signal transduction mechanism. The initial inward current was not eliminated by external application of high concentrations of tetrodotoxin,d‐tubocurarine or amiloride. Nor was it affected by the intracellular application of cyclic GMP or cyclic AMP.