Doroshenko P A, Kostiuk P G, Tsyndrenko A Ia
Neirofiziologiia. 1979;11(5):460-8.
The outward currents remaining after addition of 20-50 mM tetraethylammonium (TEA) to the extracellular solution were studied on perfused isolated neurons from Helix pomatia. A potassium-carried noninactivating outward current with potential-dependence and kinetics different from those of TEA-sensitive potassium currents was found. This TEA-resistant current includes a component depending on the presence of the inward calcium current. It could be abolished by replacing extracellular calcium by magnesium ions, by blocking the calcium channels with extracellular cadmium ions and their distruction by intracellular fluorid ions. An increase in the level of intracellular free carcium (by perfusing the cell with solutions containing Ca-EGTA buffer) potentiated the TEA-resistant component of the outward current and the removal of free calcium by EGTA decreased it. A conclusion is made that the somatic membrane contains outward current channels which can be activated only when calcium ions are bound to its inner surface.
在添加20 - 50 mM四乙铵（TEA）到细胞外溶液后，对灌注的光滑双脐螺离体神经元中剩余的外向电流进行了研究。发现了一种由钾携带的非失活性外向电流，其电位依赖性和动力学与TEA敏感的钾电流不同。这种TEA抗性电流包括一个依赖于内向钙电流存在的成分。通过用镁离子替代细胞外钙、用细胞外镉离子阻断钙通道以及用细胞内氟离子破坏钙通道，该电流可以被消除。细胞内游离钙水平的增加（通过用含有Ca - EGTA缓冲液的溶液灌注细胞）增强了外向电流的TEA抗性成分，而用EGTA去除游离钙则使其降低。得出的结论是，体细胞的膜含有外向电流通道，只有当钙离子与其内表面结合时，这些通道才能被激活。
