Stretch activated ion channels in ventricular myocytes |
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Authors: | Dr William Craelius Victor Chen Nabil El-Sherif |
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Institution: | (1) Department of Cardiology, State University of New York, 11209 Brooklyn, NY, USA;(2) Department of Biophysics, SUNY, 14214 Buffalo, NY, USA;(3) Present address: Department of Cardiology, Veterans' Administration Medical Center, 800 Poly Place, 11209 Brooklyn, NY, USA |
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Abstract: | Patch-clamp recordings from ventricular myocytes of neonatal rats identified ionic channels that open in response to membrane stretch caused by negative pressures (1 to 6 cm Hg) in the electrode. The stretch response, consisting of markedly increased channel opening frequency, was maintained, with some variability, during long (>40 seconds) stretch applications. The channels have a conductance averaging 120 pS in isotonic KCl, have a mean reversal potential 31 mV depolarized from resting membrane potential, and do not require external Ca++ for activation. The channels appear to be relatively non-selective for cations. Since they are gated by physiological levels of tension, stretch-activated channels may represent, a cellular control system wherein beat-to-beat tension and/or osmotic balance modulate a portion of membrane conductance.Abbreviations SACs
stretch-activated channels
- HEPES
4-(2-hydroxyethyl)-1-piperazine-ethanesulfonic acid |
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Keywords: | channels ventricle myocyte voltage clamp stretch receptor |
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