|
|
||||||||
AJP - Heart and Circulatory Physiology, Vol 266, Issue 1 182-H190, Copyright © 1994 by American Physiological Society
ARTICLES |
A. Ogbaghebriel and A. Shrier
Department of Physiology, McGill University, Montreal, Quebec, Canada.
Outward currents were measured in single rabbit atrial myocytes using the whole cell configuration of the patch-clamp technique in the presence of tetrodotoxin (5-10 microM) and MnCl2 (2 mM) to block inward currents. Depolarizing voltage-clamp steps from a holding potential of -80 mV elicited a predominant 4-aminopyridine (4-AP)-sensitive transient outward current (Ito). Inhibitors of oxidative metabolism, 2,4-dinitrophenol (DNP; 100 microM) and cyanide (3 mM) abolished Ito and caused a large increase in the steady-state outward current. This steady-state outward current was inhibited by glibenclamide (5 microM), a blocker of the ATP-regulated potassium current (IKATP). In the presence of DNP, glibenclamide (5 microM) not only inhibited IKATP but also partially restored Ito. Absence of ATP from the pipette produced effects on outward currents similar to those induced by DNP or cyanide. We conclude that metabolic inhibition abolishes Ito in rabbit atrial myocytes and suggest that ATP may be required for the activation of the channel.
This article has been cited by other articles:
![]() |
S. Tessier, P. Karczewski, E.-G. Krause, Y. Pansard, C. Acar, M. Lang-Lazdunski, J.-J. Mercadier, and S. N. Hatem Regulation of the Transient Outward K+ Current by Ca2+/Calmodulin-Dependent Protein Kinases II in Human Atrial Myocytes Circ. Res., October 29, 1999; 85(9): 810 - 819. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Wang, J. Feng, H. Shi, A. Pond, J. M. Nerbonne, and S. Nattel Potential Molecular Basis of Different Physiological Properties of the Transient Outward K+ Current in Rabbit and Human Atrial Myocytes Circ. Res., March 19, 1999; 84(5): 551 - 561. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. J. Rozanski, Z. Xu, K. Zhang, and K. P. Patel Altered K+ current of ventricular myocytes in rats with chronic myocardial infarction Am J Physiol Heart Circ Physiol, January 1, 1998; 274(1): H259 - H265. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. P. Levy, N. S. Levy, J. Loscalzo, A. Calderone, N. Takahashi, K.-T. Yeo, G. Koren, W. S. Colucci, and M. A. Goldberg Regulation of Vascular Endothelial Growth Factor in Cardiac Myocytes Circ. Res., May 1, 1995; 76(5): 758 - 766. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |