| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
AJP - Cell Physiology, Vol 265, Issue 5 C1201-C1210, Copyright © 1993 by American Physiological Society
ARTICLES |
D. W. Whalley, L. C. Hool, R. E. Ten Eick and H. H. Rasmussen
Department of Cardiology, Royal North Shore Hospital, Sydney, New South Wales, Australia.
The effect on the sarcolemmal Na(+)-K+ pump of exposure to anisosmolar solutions was examined using whole cell patch clamping and ion-selective microelectrodes. Na(+)-K+ pump currents were measured in single ventricular myocytes by using pipette Na+ concentrations ([Na]pip) of 0-70 mM. The relationship between [Na]pip and pump current was well described by the Hill equation. The [Na]pip for half-maximal pump current (K0.5) was 21.4 mM in isosmolar (310 mosM) solution. K0.5 was 12.8 mM during cell swelling in hyposmolar solution (240 mosM) and 39.0 mM during cell shrinkage in hyperosmolar solution (464 mosM). The maximal pump currents, derived from the best fit of the Hill equation, and the Hill coefficients were similar in isosmolar, hyposmolar, and hyperosmolar solutions. A sustained (> 20 min) decrease in the intracellular Na+ activity developed during exposure of intact papillary muscles to hyposmolar solutions, and a sustained increase developed during exposure to hyperosmolar solutions. We conclude that osmotic myocyte swelling stimulates the sarcolemmal Na(+)-K+ pump at near-physiological levels of intracellular Na+, whereas shrinkage inhibits the pump. These changes are due to increases and decreases, respectively, in the apparent affinity of the pump for Na+.
This article has been cited by other articles:
|
|
 |
|
  J. P. Reeves, M. Abdellatif, and M. Condrescu The sodium-calcium exchanger is a mechanosensitive transporter J. Physiol., March 15, 2008; 586(6): 1549 - 1563. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. G. Glitsch Electrophysiology of the Sodium-Potassium-ATPase in Cardiac Cells Physiol Rev, October 1, 2001; 81(4): 1791 - 1826. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Mardini, A. S. Mihailidou, A. Wong, and H. H. Rasmussen Cyclosporine and FK506 Differentially Regulate the Sarcolemmal Na+-K+ Pump J. Pharmacol. Exp. Ther., April 12, 2001; 297(2): 804 - 810. [Abstract] [Full Text]
|
|
|
|
|
|
O. M. Sejersted and G. Sjogaard Dynamics and Consequences of Potassium Shifts in Skeletal Muscle and Heart During Exercise Physiol Rev, October 1, 2000; 80(4): 1411 - 1481. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Brette, S. C. Calaghan, S. Lappin, E. White, J. Colyer, and J.-Y. Le Guennec Biphasic effects of hyposmotic challenge on excitation-contraction coupling in rat ventricular myocytes Am J Physiol Heart Circ Physiol, October 1, 2000; 279(4): H1963 - H1971. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. S. Ho, H. Liu, P. M. Cala, and S. E. Anderson Hypertonic perfusion inhibits intracellular Na and Ca accumulation in hypoxic myocardium Am J Physiol Cell Physiol, May 1, 2000; 278(5): C953 - C964. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. S. Hansen, K. A. Buhagiar, D. F. Gray, and H. H. Rasmussen Voltage-dependent stimulation of the Na+-K+ pump by insulin in rabbit cardiac myocytes Am J Physiol Cell Physiol, March 1, 2000; 278(3): C546 - C553. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. S. Mihailidou, H. Bundgaard, M. Mardini, P. S. Hansen, K. Kjeldsen, and H. H. Rasmussen Hyperaldosteronemia in Rabbits Inhibits the Cardiac Sarcolemmal Na+-K+ Pump Circ. Res., January 7, 2000; 86(1): 37 - 42. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. Buhagiar, P. S. Hansen, D. F. Gray, A. S. Mihailidou, and H. H. Rasmussen Angiotensin regulates the selectivity of the Na+-K+ pump for intracellular Na+ Am J Physiol Cell Physiol, September 1, 1999; 277(3): C461 - C468. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. L. Bewick, C. Fernandes, A. D. Pitt, H. H. Rasmussen, and D. W. Whalley Mechanisms of Na+-K+ pump regulation in cardiac myocytes during hyposmolar swelling Am J Physiol Cell Physiol, May 1, 1999; 276(5): C1091 - C1099. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. E. Befroy, T. Powell, G. K. Radda, and K. Clarke Osmotic shock: modulation of contractile function, pHi, and ischemic damage in perfused guinea pig heart Am J Physiol Heart Circ Physiol, April 1, 1999; 276(4): H1236 - H1244. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Sarfaraz and C. L. Fraser Effects of arginine vasopressin on cell volume regulation in brain astrocyte in culture Am J Physiol Endocrinol Metab, March 1, 1999; 276(3): E596 - E601. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. F. Gray, A. S. Mihailidou, P. S. Hansen, K. A. Buhagiar, N. L. Bewick, H. H. Rasmussen, and D. W. Whalley Amiodarone Inhibits the Na+-K+ Pump in Rabbit Cardiac Myocytes after Acute and Chronic Treatment J. Pharmacol. Exp. Ther., January 1, 1998; 284(1): 75 - 82. [Abstract] [Full Text]
|
|
|
|
|
|
F. LANG, G. L. BUSCH, M. RITTER, H. VOLKL, S. WALDEGGER, E. GULBINS, and D. HAUSSINGER Functional Significance of Cell Volume Regulatory Mechanisms Physiol Rev, January 1, 1998; 78(1): 247 - 306. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. S. Mihailidou, K. A. Buhagiar, and H. H. Rasmussen Na+ influx and Na+-K+ pump activation during short-term exposure of cardiac myocytes to aldosterone Am J Physiol Cell Physiol, January 1, 1998; 274(1): C175 - C181. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G.-R. Li, M. Zhang, L. S. Satin, and C. M. Baumgarten Biphasic effects of cell volume on excitation-contraction coupling in rabbit ventricular myocytes Am J Physiol Heart Circ Physiol, April 1, 2002; 282(4): H1270 - H1277. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
