THE INFLUENCE OF CAPSAICIN ON MEMBRANE CURRENTS IN DORSAL-ROOT GANGLION NEURONS OF GUINEA-PIG AND CHICKEN
THE INFLUENCE OF CAPSAICIN ON MEMBRANE CURRENTS IN DORSAL-ROOT GANGLION NEURONS OF GUINEA-PIG AND CHICKEN
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DOI：
10.1007/bf00583794
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发表时间：
1987-08-01
影响因子：
4.5
通讯作者：
WEYRICH, M
中科院分区：
文献类型：
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作者：
PETERSEN, M;PIERAU, FK;WEYRICH, M
采用电压钳技术和细胞内灌流技术，研究辣椒素对豚鼠和鸡背根神经节（DRG）神经元电压依赖性膜电流的影响。在这两个物种中，施用辣椒素（3. 10-5 M）使快失活钾电流的幅值降低，并加速其失活。相反，3，4-二氨基吡啶（3，4-DAP）减少快钾电流而不影响失活。辣椒素和3，4-DAP联合应用比单独使用更有效。辣椒素可抑制慢钾电流，而3，4-DAP对慢钾电流无影响。辣椒素（3. 10-5 M）对快外向电流影响不大，但主要降低慢钾电流的幅度。根据豚鼠神经元对河豚毒素（TTX）的敏感性，可将钠电流分为两个亚群。在I型神经元的钠电流完全被TTX阻断; II型神经元表现出TTX敏感以及TTX抗性内向电流。辣椒素（3. 10-5 M）降低了两个电流分量的最大幅度。失活的时间过程被延迟，只有在TTX耐钠电流。辣椒素对豚鼠和鸡背根节神经元钠电流的影响相似。在鸡背根节神经元中，只观察到TTX敏感电流。在这两个物种的稳态失活的钠电流被辣椒素转移到更负的电位。
The effect of capsaicin on voltage-dependent membrane currents of isolated dorsal root ganglia (DRG) neurones of guinea-pig and chicken were investigated by the voltage-clamp technique and intracellular perfusion. In both species, administration of capsaicin (3 .cntdot. 10-5 M) to the outer surface of the cell membrane reduced the amplitude and accelerated the inactivation of the fast inactivating potassium current. In contrast, 3,4-diaminopyridine (3,4-DAP) reduced the fast potassium current without affecting the inactivation. Combined application of capsaicin and 3,4-DAP was more effective than either drug alone. The slow potassium current was diminished by capsaicin but not affected by 3,4-DAP. Capsaicin (3 .cntdot. 10-5 M) applied to the internal surface of the membrane had little effect on the fast outward current but primarily decreased the amplitude of the slow potassium current. Two subpopulations of sodium currents could be demonstrated in guinea-pig neurones according to their tetrodotoxin (TTX) sensitivity. In type I neurones the sodium current was completely blocked by TTX; type II neurones exhibited a TTX-sensitive as well as a TTX-resistant inward current. Capsaicin (3 .cntdot. 10-5 M) applied externally reduced the maximal amplitude of both current components. The time course of inactivation was delayed only in the TTX-resistant sodium current. The effect of capsaicin on Na-currents of DRG neurones was similar in guinea-pigs and chicken. In DRG neurones of chicken, only TTX-sensitive currents were observed. In both species the steady-state inactivation of the sodium currents was shifted by capsaicin to more negative potentials.