Hisada T, Walsh J V, Singer J J
Department of Physiology, University of Massachusetts Medical Center, Worcester 01655.
Pflugers Arch. 1993 Jan;422(4):393-6. doi: 10.1007/BF00374296.
Stretch-inactivated channels (SICs) were identified in single smooth muscle cells freshly dissociated from the stomach of the toad, Bufo marinus. In both cell-attached and excised inside-out patches, negative pressure applied to the extracellular surface of the membrane patch suppressed the activity of SICs. These channels were permeable to cations and were not significantly permeable to Cl-. The current-voltage relationship showed outward rectification in cell-attached patches with high NaCl in the pipette solution (2 mM MgCl2), and the slope conductance at negative potentials was approximately 8 pS under these conditions. When divalent cations were eliminated from the pipette solution, the slope conductance at negative potentials increased to approximately 30 pS. No significant voltage dependence of SIC gating could be observed between -100 mV and 60 mV.
在从海蟾蜍（Bufo marinus）胃中新鲜分离出的单个平滑肌细胞中鉴定出拉伸失活通道（SICs）。在细胞贴附式和切除式内面向外膜片中，对膜片细胞外表面施加负压会抑制SICs的活性。这些通道对阳离子具有通透性，而对Cl-的通透性不显著。电流-电压关系显示，在移液管溶液中含有高浓度NaCl（2 mM MgCl2）的细胞贴附式膜片中呈外向整流，在这些条件下负电位时的斜率电导约为8 pS。当从移液管溶液中去除二价阳离子时，负电位时的斜率电导增加到约30 pS。在-100 mV至60 mV之间未观察到SIC门控对电压有明显依赖性。
