Differential sensitivity of cardiac K+(ATP) channels to guanine nucleotides--evidence for a heterogeneous channel population.
In cell-free patches from cultured neonatal rat cardiocytes, the cytosolic presence of GTP-gamma-S (100 mumol/l) or GDP-beta-S (100 mumol/l) activated K+(ATP) channels. GTP-gamma-S required cytosolic Mg++, suggesting that an activated G-protein causes the increase in open probability. The great variations of the channel response to GTP-gamma-S and GDP-beta-S indicates that cardiac K+(ATP) channels represent a heterogeneous family.
Benz
I
I
Physiological Institute, University Freiburg, Federal Republic of Germany.
Kohlhardt
M
M
D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D004553:Electric Conductivity / Q000187:drug effects; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology*; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D006321:Heart / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D013873:Thionucleotides / Q000494:pharmacology*
D015221:Potassium Channels; D013873:Thionucleotides; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C023427:guanosine 5'-O-(2-thiodiphosphate); D000255:Adenosine Triphosphate