AJP - Heart and Circulatory Physiology, Vol 272, Issue 4 1741-H1750, Copyright © 1997 by American Physiological Society

ARTICLES

Development of inwardly rectifying K+ channel family in rat ventricular myocytes

L. H. Xie, M. Takano and A. Noma
Department of Physiology and Biophysics, Faculty of Medicine, Kyoto University, Japan.

The ATP-sensitive K+ current (I(K,ATP)), the inward rectifier K+ current (I(K1)), and the acetylcholine-activated K+ current (I(K,ACh)) were recorded in fetal, neonatal, and adult rat ventricular myocytes using the patch-clamp technique. The density (pA/pF) of I(K1) increased from gestation day 10 through neonatal day 1 and then decreased after neonatal day 30. The density of I(K,ATP) activated maximally by metabolic inhibition changed in parallel with the I(K1) density, and the density of I(K,ATP) channel distribution was 1.3 times higher than that of I(K1) throughout the development. We failed to observe developmental changes in the single-channel conductance and the mean open time of I(K1) and I(K,ATP) channels. However, the open probability of the I(K,ATP) channel was lower in fetuses, and the sensitivity to ATP was highest in 1-day neonates. I(K,ACh) were present in the ventricle at all stages of development but at a much lower density than in atrium. The relationship between the resting membrane potential and the development of the inwardly rectifying K-channel family is discussed.

This article has been cited by other articles:

				M. D. Harrell, S. Harbi, J. F. Hoffman, J. Zavadil, and W. A. Coetzee Large-scale analysis of ion channel gene expression in the mouse heart during perinatal development Physiol Genomics, February 12, 2007; 28(3): 273 - 283. [Abstract] [Full Text] [PDF]

				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]

				N. Bursac, M. Papadaki, R. J. Cohen, F. J. Schoen, S. R. Eisenberg, R. Carrier, G. Vunjak-Novakovic, and L. E. Freed Cardiac muscle tissue engineering: toward an in vitro model for electrophysiological studies Am J Physiol Heart Circ Physiol, August 1, 1999; 277(2): H433 - H444. [Abstract] [Full Text] [PDF]

				E. Carmeliet Cardiac Ionic Currents and Acute Ischemia: From Channels to Arrhythmias Physiol Rev, July 1, 1999; 79(3): 917 - 1017. [Abstract] [Full Text] [PDF]

				X. Han, I. Kubota, O. Feron, D. J. Opel, M. A. Arstall, Y.-Y. Zhao, P. Huang, M. C. Fishman, T. Michel, and R. A. Kelly Muscarinic cholinergic regulation of cardiac myocyte ICa-L is absent in mice with targeted disruption of endothelial nitric oxide synthase PNAS, May 26, 1998; 95(11): 6510 - 6515. [Abstract] [Full Text] [PDF]

				T. Y. Nakamura, M. Artman, B. Rudy, and W. A. Coetzee Inhibition of rat ventricular IK1 with antisense oligonucleotides targeted to Kir2.1 mRNA Am J Physiol Heart Circ Physiol, March 1, 1998; 274(3): H892 - H900. [Abstract] [Full Text] [PDF]