Transient Outward Current?
نویسندگان
چکیده
To gain insight into the molecular basis of cardiac repolarization, we have expressed K' channels cloned from ventricular myocardium in Xenopus oocytes. A recently identified human cardiac K' channel isoform (human Kvl.4) has properties similar to the 4-aminopyridine-sensitive calcium-insensitive component of the cardiac transient outward current. However, these channels recovered from inactivation much slower than native channels. Hybrid channels consisting of subunits from different K' channel clones (delayed rectifier channels [Kvl.l, Kv1.2, and Kvl.5] and Kvl.4) were created by coinjection of cRNAs in oocytes. Multimeric channels consisting of Kvl.4:Kvl.1, Kvl.4:Kvl.2, and Kvl.4:Kvl.5 were expressed and compared. The hybrid channels displayed characteristics of heterotetrameric channels with kinetics that
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A variety of outward currents exists in ventricular myocardium of different species influencing action potential duration and electrical activity. Transient outward currents have been reported in ventricular tissue of some animals but are small or absent in others. This study was conducted to investigate whether a transient outward current exists in human ventricular myocardium and to character...
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Li, Gui-Rong, Haiying Sun, and Stanley Nattel. Characterization of a transient outward K1 current with inward rectification in canine ventricular myocytes. Am. J. Physiol. 274 (Cell Physiol. 43): C577–C585, 1998.—The threshold potential for the classical depolarization-activated transient outward K1 current and Cl2 current is positive to 230 mV. With the whole cell patch technique, a transient ...
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There have been periodic reports of nonclassic (4-aminopyridine insensitive) transient outward K+ current in guinea pig ventricular myocytes, with the most recent one describing a novel voltage-gated inwardly rectifying type. In the present study, we have investigated a transient outward current that overlaps inward Ca2+ current (I(Ca,L)) in myocytes dialyzed with 10 mM K+ solution and superfus...
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