Zefirov A L, Shakir'ianova D M
Neirofiziologiia. 1992;24(6):678-83.
Mechanisms of the exogenic acetylcholine (ACh) effect on ionic currents of nerve endings (NE) were investigated by extracellular recording of NE at the cutaneous pectoris muscle of frog. It was found that ACh in concentrations 0.1-0.6 mmol/l increased the third phase of the nerve ending response, while in concentrations 0.7-2.0 mmol/l-decreased it. Tubocurarine and atropine did not alter the ACh effect. It has been also revealed that growth of the third phase of NE response, induced by ACh, occurs in the presence of calcium channel blockers and disappears under the influence of 4-aminopyridine and tetraethylammonium. In calcium-free solution or when the calcium current is blocked the suppressive effect of ACh disappears. The mechanisms of exogenic and endogenic ACh effects on the potential-sensitive and calcium-activated potassium NE currents are discussed.
通过对青蛙胸皮肌神经末梢（NE）进行细胞外记录，研究了外源性乙酰胆碱（ACh）对神经末梢离子电流的作用机制。发现浓度为0.1 - 0.6 mmol/l的ACh增加了神经末梢反应的第三阶段，而浓度为0.7 - 2.0 mmol/l时则降低了该阶段。筒箭毒碱和阿托品不改变ACh的作用。还发现，由ACh诱导的NE反应第三阶段的增强在钙通道阻滞剂存在时出现，而在4 - 氨基吡啶和四乙铵的影响下消失。在无钙溶液中或钙电流被阻断时，ACh的抑制作用消失。讨论了外源性和内源性ACh对神经末梢电位敏感和钙激活钾电流的作用机制。
