|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Articles in PresS, published online ahead of print October 10, 2002
Am J Physiol Heart Circ Physiol, 10.1152/ajpheart.00687.2002
Submitted on August 5, 2002
Accepted on October 7, 2002
1 CNRS UMR 6542, Faculte des Sciences, Universite de Tours, TOURS, France
* To whom correspondence should be addressed. E-mail: findlay{at}rabelais.univ-tours.fr.
A unique transient outward K+ current (Ito) has been described to result from the removal of extracellular Ca2+ from ventricular myocytes of the guinea-pig (Inoue and Imanaga Am. J. Physiol. 264: C1434-C1438, 1993). This study addressed the question of whether this current represented K+-selective Ito or the efflux of K+ via L-type Ca2+ channels. This outward current was inhibited by Cd2+, Ni2+, Co2+ and La3+. It was inhibited by nifedipine. All of these compounds were equally effective inhibitors of the L-type Ca2+ current. It was not inhibited by 4-AP. Apparent inhibition of the outward current by extracellular Ca2+ was shown to result from the displacement of the reversal potential of cation flux through L-type Ca2+ channels. The current was found not to be K+-selective but also permeant to Cs+. The voltage-dependence of inactivation of the outward current was identical to that of the L-type Ca2+ current. It is concluded that extracellular Ca2+ does not mask an A-type K+ current in guinea-pig ventricular myocytes.
This article has been cited by other articles:
![]() |
E. H. Medei, J. H.M. Nascimento, R. C. Pedrosa, L. Barcellos, M. O. Masuda, S. Sicouri, M. V. Elizari, and A. C. Campos de Carvalho Antibodies with beta-adrenergic activity from chronic chagasic patients modulate the QT interval and M cell action potential duration Europace, July 1, 2008; 10(7): 868 - 876. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Veeraraghavan and S. Poelzing Mechanisms underlying increased right ventricular conduction sensitivity to flecainide challenge Cardiovasc Res, March 1, 2008; 77(4): 749 - 756. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Dong, X. Sun, A. A. Prinz, and H.-S. Wang Effect of simulated Ito on guinea pig and canine ventricular action potential morphology Am J Physiol Heart Circ Physiol, August 1, 2006; 291(2): H631 - H637. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Zhabyeyev, T. Asai, S. Missan, and T. F. McDonald Transient outward current carried by inwardly rectifying K+ channels in guinea pig ventricular myocytes dialyzed with low-K+ solution Am J Physiol Cell Physiol, November 1, 2004; 287(5): C1396 - C1403. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Rosati and D. McKinnon Regulation of Ion Channel Expression Circ. Res., April 16, 2004; 94(7): 874 - 883. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Zicha, I. Moss, B. Allen, A. Varro, J. Papp, R. Dumaine, C. Antzelevich, and S. Nattel Molecular basis of species-specific expression of repolarizing K+ currents in the heart Am J Physiol Heart Circ Physiol, October 1, 2003; 285(4): H1641 - H1649. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |