ATP-sensitive K+ channels in rat ventricular myocytes are blocked and inactivated by internal divalent cations. Export

@article{citeulike:379731, abstract = {K+ currents were recorded from ATP-sensitive channels in inside-out patches from isolated rat ventricular myocytes. In the absence of internal divalent cations the current voltage relationship could be described by constant-field assumptions with a permeability of 1.25 X 10(-13) cm2/s; outward currents saturated under a high driving force for K+ movement. Internal 0.1-5.0 mM Mg2+, 0.1 microM Ca2+ and 10 mM Na+ each depressed the flux of K+ ions moving outwards through open channels. Internal 0.1-5.0 mM Mg2+, 0.1-1.0 microM Ca2+ and 1-10 microM Ba2+ and Sr2+ blocked K+ channel activity in a dose- and voltage-dependent manner. Run-down channels could be reactivated by Mg-ATP, but not by AMP-PNP, ATP gamma S or Mg-free ATP which suggested that phosphorylation of the channels was involved in their activity. Ca2+ (greater than = 1 microM) and Sr2+ (1 mM) markedly inactivated K+ ATP channels, millimolar Ba2+ or Mg2+ were less effective. This suggested that the run down of the channels was a Ca2+-dependent dephosphorylation of the K+ channel protein.}, address = {Laboratoire de Biomembranes et des Ensembles neuronaux associe au CNRS, Universit\'{e} de Paris XI, Orsay, France.}, author = {Findlay, I.}, citeulike-article-id = {379731}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/2446256}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=2446256}, issn = {0031-6768}, journal = {Pflugers Arch}, keywords = {cations, heart, i-katp, ischemia, myocardium, myocyte, rat, ventricles}, month = {October}, number = {3}, pages = {313--320}, posted-at = {2005-11-03 19:44:55}, priority = {3}, title = {ATP-sensitive K+ channels in rat ventricular myocytes are blocked and inactivated by internal divalent cations.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/2446256}, volume = {410}, year = {1987} }

TY - JOUR ID - citeulike:379731 L3 - citeulike-article-id:379731 N2 - K+ currents were recorded from ATP-sensitive channels in inside-out patches from isolated rat ventricular myocytes. In the absence of internal divalent cations the current voltage relationship could be described by constant-field assumptions with a permeability of 1.25 X 10(-13) cm2/s; outward currents saturated under a high driving force for K+ movement. Internal 0.1-5.0 mM Mg2+, 0.1 microM Ca2+ and 10 mM Na+ each depressed the flux of K+ ions moving outwards through open channels. Internal 0.1-5.0 mM Mg2+, 0.1-1.0 microM Ca2+ and 1-10 microM Ba2+ and Sr2+ blocked K+ channel activity in a dose- and voltage-dependent manner. Run-down channels could be reactivated by Mg-ATP, but not by AMP-PNP, ATP gamma S or Mg-free ATP which suggested that phosphorylation of the channels was involved in their activity. Ca2+ (greater than = 1 microM) and Sr2+ (1 mM) markedly inactivated K+ ATP channels, millimolar Ba2+ or Mg2+ were less effective. This suggested that the run down of the channels was a Ca2+-dependent dephosphorylation of the K+ channel protein. IS - 3 JF - Pflugers Arch SN - 0031-6768 AD - Laboratoire de Biomembranes et des Ensembles neuronaux associe au CNRS, Université de Paris XI, Orsay, France. EP - 320 TI - ATP-sensitive K+ channels in rat ventricular myocytes are blocked and inactivated by internal divalent cations. VL - 410 SP - 313 KW - cations KW - heart KW - i-katp KW - ischemia KW - myocardium KW - myocyte KW - rat KW - ventricles AU - Findlay, I PY - 1987/10// UR - http://view.ncbi.nlm.nih.gov/pubmed/2446256 ER -