AJP - Heart and Circulatory Physiology, Vol 270, Issue 5 1676-H1686, Copyright © 1996 by American Physiological Society

ARTICLES

Properties of sodium and potassium currents of cultured adult human atrial myocytes

J. Feng, G. R. Li, B. Fermini and S. Nattel
Department of Medicine, Montreal Heart Institute, Quebec, Canada.

Cultured cell systems are valuable for the study of regulation of phenotypic expression, but little is known about the electrophysiological properties of human cardiac tissues in culture. The present studies were designed to determine the feasibility of maintaining human atrial myocytes in primary culture and to assess changes in Na+ (INa) and K+ (Ito, transient outward, and Ikur, ultra-rapid delayed rectifier) currents. Within 24 h of culture, cells assumed an avoid shape, which they maintained for up to 7 days. The voltage dependence, kinetics, and density of INa were unchanged in culture. The activation properties of Ito (kinetics and voltage dependence) were not altered, but Ito density (current normalized to cell capacitance) was reduced and inactivation properties were altered (negative shift in voltage dependence and slowed kinetics) in cultured compared with fresh cells. The absolute current amplitude, kinetics, voltage dependence, and 4-aminopyridine sensitivity of IKur were unchanged, but current density was increased. All changes in ionic currents occurred within 24 h of culture and remained stable for the next 4 days. We conclude that human atrial myocytes can be maintained in primary culture, that the qualitative properties of INa, Ito, and IKur remain constant but that some quantitative changes occur, and that cultured human atrial myocytes may be valuable for studies of the molecular mechanisms and regulation of cardiac channel function in humans.

This article has been cited by other articles:

				A. Nurmi and M. Vornanen Electrophysiological properties of rainbow trout cardiac myocytes in serum-free primary culture Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2002; 282(4): R1200 - R1209. [Abstract] [Full Text] [PDF]

				H. M. Himmel, D. Meyer zu Heringdorf, E. Graf, D. Dobrev, A. Kortner, S. Schüler, K. H. Jakobs, and U. Ravens Evidence for Edg-3 Receptor-Mediated Activation of IK.ACh by Sphingosine-1-Phosphate in Human Atrial Cardiomyocytes Mol. Pharmacol., August 1, 2000; 58(2): 449 - 454. [Abstract] [Full Text]

				M. Courtemanche, R. J. Ramirez, and S. Nattel Ionic mechanisms underlying human atrial action potential properties: insights from a mathematical model Am J Physiol Heart Circ Physiol, July 1, 1998; 275(1): H301 - H321. [Abstract] [Full Text] [PDF]

				J. Feng, B. Wible, G.-R. Li, Z. Wang, and S. Nattel Antisense Oligodeoxynucleotides Directed Against Kv1.5 mRNA Specifically Inhibit Ultrarapid Delayed Rectifier K+ Current in Cultured Adult Human Atrial Myocytes Circ. Res., April 19, 1997; 80(4): 572 - 579. [Abstract] [Full Text]