This Article Full Text Alert me when this article is cited Alert me if a correction is posted Citation Map 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 Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wang, Z. Articles by Noma, A. Search for Related Content PubMed PubMed Citation Articles by Wang, Z. Articles by Noma, A.

(Circulation Research. 1996;78:466-474.)
© 1996 American Heart Association, Inc.

Articles

Cell DistensionInduced Increase of the Delayed Rectifier K⁺ Current in Guinea Pig Ventricular Myocytes

Zhuren Wang, Tamotsu Mitsuiye, Akinori Noma

From the Department of Physiology, Faculty of Medicine, Kyoto (Japan) University.

Correspondence to Dr T. Mitsuiye, Department of Physiology, Faculty of Medicine, Kyoto University, Sakyo-Ku, Kyoto 606, Japan.

Abstract Single ventricular myocytes of guinea pig heart were distended by applying a positive pressure of 5 to 20 mm Hg in the pipette during the whole-cell voltage clamp. The amplitude of delayed rectifier K⁺ current (I_K) was increased by 1.5 times, whereas the inward rectifier K⁺ current was scarcely affected. The increase of I_K was reversible by applying a negative pressure of -10 to -30 mm Hg accompanied by shrinkage of the inflated cell. This response of I_K was largely attributed to the E-4031–insensitive component of I_K. The fully activated current amplitude, measured using long-lasting depolarizing pulses (>30 seconds) to +60 mV, was increased by the cell distension. The activation time course of I_K during the long pulse consisted of more than three exponential components, and the slowest time constant was decreased by the distension from control 20.2±7.7 seconds (n=4) to 7.6±1.6 seconds (n=5). We failed to detect an involvement of microtubules or microfilaments, protein kinase C, and Ca²⁺ in the inflation-mediated increase of I_K.

Key Words: delayed rectifier K⁺ current • ventricular myocytes • guinea pig hearts • membrane stretch • cytoskeleton

This article has been cited by other articles:

				C. S. Nicolas, K.-H. Park, A. El Harchi, J. Camonis, R. S. Kass, D. Escande, J. Merot, G. Loussouarn, F. Le Bouffant, and I. Baro IKs response to protein kinase A-dependent KCNQ1 phosphorylation requires direct interaction with microtubules Cardiovasc Res, August 1, 2008; 79(3): 427 - 435. [Abstract] [Full Text] [PDF]

				Z. Ren and C. M. Baumgarten Antagonistic regulation of swelling-activated Cl- current in rabbit ventricle by Src and EGFR protein tyrosine kinases Am J Physiol Heart Circ Physiol, June 1, 2005; 288(6): H2628 - H2636. [Abstract] [Full Text] [PDF]

				B. B. Lerman, E. D. Engelstein, and D. Burkhoff Mechanoelectrical Feedback: Role of {beta}-Adrenergic Receptor Activation in Mediating Load-Dependent Shortening of Ventricular Action Potential and Refractoriness Circulation, July 24, 2001; 104(4): 486 - 490. [Abstract] [Full Text] [PDF]

				T. L. Riemer, E. A. Sobie, and L. Tung Stretch-induced changes in arrhythmogenesis and excitability in experimentally based heart cell models Am J Physiol Heart Circ Physiol, August 1, 1998; 275(2): H431 - H442. [Abstract] [Full Text] [PDF]

				D. K. Bowles, M. H. Laughlin, and M. Sturek Exercise training increases K+-channel contribution to regulation of coronary arterial tone J Appl Physiol, April 1, 1998; 84(4): 1225 - 1233. [Abstract] [Full Text] [PDF]

				M. J. Reiter, M. Landers, Z. Zetelaki, C. J. H. Kirchhof, and M. A. Allessie Electrophysiological Effects of Acute Dilatation in the Isolated Rabbit Heart : Cycle Length–Dependent Effects on Ventricular Refractoriness and Conduction Velocity Circulation, December 2, 1997; 96(11): 4050 - 4056. [Abstract] [Full Text]

				H. F. Clemo and C. M. Baumgarten Swelling-activated Gd3+-sensitive Cation Current and Cell Volume Regulation in Rabbit Ventricular Myocytes J. Gen. Physiol., September 1, 1997; 110(3): 297 - 312. [Abstract] [Full Text] [PDF]

				Z. Wang, T. Mitsuiye, S. A. Rees, and A. Noma Regulatory Volume Decrease of Cardiac Myocytes Induced by {beta}-Adrenergic Activation of the Cl- Channel in Guinea Pig J. Gen. Physiol., July 1, 1997; 110(1): 73 - 82. [Abstract] [Full Text] [PDF]