Abstract
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 ∼30 pS. No significant voltage dependence of SIC gating could be observed between −100 mV and 60 mV.
References
Ding JP, Bowman CL, Sokabe M, Sachs F (1989) Mechanical transduction in glial cells: SACs and SICs. Biophys J 55: 244a
Fong P, Turner PR, Denetclaw WF, Steinhardt RA (1990) Increased activity of calcium leak channels in myotubes of Duchenne human and mdx mouse origin. Science 250: 673–676
Franco A Jr, Lansman JB (1990) Calcium entry through stretch-inactivated ion channels in mdx myotubes. Nature 344: 670–673
Hamill OP, Marty A, Neher E, Sakmann B, Sigworth FJ (1981) Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflügers Arch 391: 85–100
Hisada T, Ordway RW, Kirber MT, Singer JJ, Walsh JV Jr (1991) Hyperpolarization-activated cationic channels in smooth muscle cells are stretch sensitive. Pflügers Arch 417: 493–499
Kirber MT, Walsh JV Jr, Singer JJ (1988) Stretch-activated ion channels in smooth muscle: a mechanism for the initiation of stretch-induced contraction. Pflügers Arch 412: 339–345
Lassignal NL, Singer JJ, Walsh JV Jr (1986) Multiple neuropeptides exert a direct effect on the same isolated single smooth muscle cells. Am J Physiol 250: C792-C798
Morris CE, Sigurdson WJ (1989) Stretch-inactivated ion channels coexist with stretch-activated ion channels. Science 243: 807–809
Morris CE (1990) Mechanosensitive Ion Channels. J Membrane Biol 113: 93–107
Van Wagoner DR (1991): Mechanosensitive ion channels in atrial myocytes. Biophys J 59: 546a
Vivaudou MB, Singer JJ, Walsh JV Jr (1986) An automated technique for analysis of current transitions in multilevel single-channel recordings. Pflügers Arch 407: 355–364
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Hisada, T., Walsh, J.V. & Singer, J.J. Stretch-inactivated cationic channels in single smooth muscle cells. Pflügers Arch. 422, 393–396 (1993). https://doi.org/10.1007/BF00374296
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DOI: https://doi.org/10.1007/BF00374296