HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Shen, J.-B. Articles by Liang, B. T. Search for Related Content PubMed PubMed Citation Articles by Shen, J.-B. Articles by Liang, B. T.

Extracellular ATP-stimulated current in wild-type and P2X₄ receptor transgenic mouse ventricular myocytes: implications for a cardiac physiologic role of P2X₄ receptors

Jian-Bing Shen^*, Achilles J. Pappano^*, and Bruce T. Liang^*,1

^* Pat and Jim Calhoun Cardiology Center and the
Department of Pharmacology, University of Connecticut Health Center, Farmington, Connecticut, USA

¹ Correspondence: Pat and Jim Calhoun Cardiology Center, MC-3946, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 06030, USA. E-mail bliang{at}uchc.edu

P2X receptors, activated by extracellular ATP, may be important in regulating cardiac function. The objective of the present study was to characterize the electrophysiologic actions of P2X₄ receptors in cardiac myocytes and to determine whether they are involved in mediating the effect of extracellular ATP. Membrane currents under voltage clamp were determined in myocytes from both wild-type (WT) and P2X₄ receptor-overexpressing transgenic (TG) mice. The P2X agonist 2-meSATP induced an inward current at –100 mV that was greater in magnitude (2-fold) in TG than in WT ventricular cells. In the presence of the P2X₄ receptor-selective allosteric enhancer ivermectin (3 µM), the 2-meSATP-stimulated current increased significantly in both WT and TG ventricular cells, consistent with an important role of P2X₄ receptors in mediating the ATP current not only in TG but also WT myocytes. That the current in both WT and TG cells showed similar voltage-dependence and reverse potential (0 mV) further suggests a role for this receptor in the normal electrophysiological action of ATP in WT murine cardiac myocytes. The P2X antagonist suramin was only able to block partially the 2-meSATP-stimulated current in WT cells, implying that both P2X₄ receptor and another yet-to-be-identified P2X receptor mediate this current.—Shen, J.-B., Pappano, A. J., Liang, B. T. Extracellular ATP-stimulated current in wild-type and P2X₄ receptor transgenic mouse ventricular myocytes: implications for a cardiac physiologic role of P2X₄ receptors.

Key Words: ion channels • membrane current • mouse • heart

This article has been cited by other articles:

				U. Gergs, P. Boknik, W. Schmitz, A. Simm, R.-E. Silber, and J. Neumann A positive inotropic effect of ATP in the human cardiac atrium Am J Physiol Heart Circ Physiol, April 1, 2008; 294(4): H1716 - H1723. [Abstract] [Full Text] [PDF]

				J.-B. Shen, R. Shutt, A. Pappano, and B. T. Liang Characterization and mechanism of P2X receptor-mediated increase in cardiac myocyte contractility Am J Physiol Heart Circ Physiol, November 1, 2007; 293(5): H3056 - H3062. [Abstract] [Full Text] [PDF]

				Y. Zhang, D. Sanchez, J. Gorelik, D. Klenerman, M. Lab, C. Edwards, and Y. Korchev Basolateral P2X4-like receptors regulate the extracellular ATP-stimulated epithelial Na+ channel activity in renal epithelia Am J Physiol Renal Physiol, June 1, 2007; 292(6): F1734 - F1740. [Abstract] [Full Text] [PDF]

				D. Sonin, J.-G. Zheng, C. Cronin, T. Sonina, and B. Liang Cardiac-specific Overexpression of Human P2X4 Purinergic Receptors Confers a Beneficial Effect in Left Anterior Descending Artery Ligation Model of Ischemic Cardiomyopathy FASEB J, April 1, 2007; 21(6): A800 - A800. [Full Text]