Reconstitution and characterization of a calcium-activated channel from heart.
This paper is the first description of a calcium-activated nonspecific cation channel in adult ventricular muscle. We report gating kinetics and ionic selectivity data from experiments performed at the single channel level. Calcium activation is described by a gating model wherein two ions are involved in the reaction. Channel gating exhibited marked voltage dependence. Ionic selectivity experiments indicated that the channel is cation-selective but unable to discriminate between Na+ and K+. We discuss evidence that this channel mediates transient inward current in ventricular tissue; thus, the channel may be involved in after depolarization-induced cardiac arrhythmias.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004285:Dogs; D006321:Heart / Q000502:physiology*; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D007700:Kinetics; D011188:Potassium / Q000378:metabolism; D011336:Probability; D012964:Sodium / Q000378:metabolism
D007473:Ion Channels; D012964:Sodium; D011188:Potassium; D002118:Calcium