AJP - Heart Information on EB 2010
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol (June 27, 2002). doi:10.1152/ajpheart.00186.2002
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
283/4/H1616    most recent
00186.2002v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (26)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tadros, G. M.
Right arrow Articles by Cheung, J. Y.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tadros, G. M.
Right arrow Articles by Cheung, J. Y.

Articles in PresS, published online ahead of print June 27, 2002
Am J Physiol Heart Circ Physiol, 10.1152/ajpheart.00186.2002
Submitted on March 4, 2002
Accepted on June 14, 2002

Effects of Na+/Ca2+ exchanger downregulation on contractility and [Ca2+]i transients in adult rat myocytes

George M. Tadros1, Xue-Qian Zhang2, Jianliang Song2, Lois L. Carl2, Lawrence I. Rothblum2, Qiang Tian2, Jeremy Dunn3, Jonathan Lytton3, and Joseph Y. Cheung4*

1 Medicine, Geisinger Medical Center, Danville, Pennsylvania, USA
2 Weis Center for Research, Geisinger Medical Center, Danville, Pennsylvania, USA
3 Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada
4 Weis Center for Research, Geisinger Medical Center, Danville, Pennsylvania, USA; Medicine, Geisinger Medical Center, Danville, Pennsylvania, USA

* To whom correspondence should be addressed. E-mail: jcheung{at}geisinger.edu.

Previous studies on myocytes isolated from rat hearts 3 wk after myocardial infarction (MI) demonstrated depressed Na+/Ca2+ exchange (NCX1), altered contractility and intracellular Ca2+ concentration ([Ca2+]i) transients. In the present study we investigated whether NCX1 downregulation in normal adult rat myocytes resulted in contractility changes observed in MI myocytes. Compared with control myocytes infected with adenovirus expressing green fluorescent protein (GFP) only, myocytes infected with adenovirus expressing both GFP and antisense (AS) to NCX1 had 30% less NCX1 (p<0.01) at 3 days and 66% less NCX1 at 6 days (p=0.0003). Half-time of relaxation from caffeine-induced contracture, an estimate of forward Na+/Ca2+ exchange activity, was twice as long (p<0.0002) in ASNCX1 myocytes. Sarcoplasmic reticulum (SR) Ca2+-ATPase abundance, SR Ca2+ uptake, resting membrane potential,action potential amplitude and duration, L-type Ca2+ current density and cell size were not affected by ASNCX1 treatment. At extracellular calcium concentration ([Ca2+]o) of 5 mM, ASNCX1 myocytes had significantly lower contraction and [Ca2+]i transient amplitudes and SR Ca2+ contents than control myocytes. At 0.6 mM [Ca2+]o, contraction and [Ca2+]i transient amplitudes and SR Ca2+ contents were significantly higher in ASNCX1 myocytes. At 1.8 mM [Ca2+]o, contraction and [Ca2+]i transient amplitudes were not different between control and ASNCX1 myocytes. This pattern of contractile and [Ca2+]i transient abnormalities in ASNCX1 myocytes mimics that observed in rat MI myocytes. We conclude that downregulation of NCX1 in adult rat myocytes resulted in decreases in both Ca2+ influx and efflux during a twitch. We suggest that depressed Na+/Ca2+ exchange activity may partly account for the contractile abnormalities after myocardial infarction.




This article has been cited by other articles:


Home page
 Physiol. Rev.Home page
J. Davis, M. V. Westfall, D. Townsend, M. Blankinship, T. J. Herron, G. Guerrero-Serna, W. Wang, E. Devaney, and J. M. Metzger
Designing Heart Performance by Gene Transfer
Physiol Rev, October 1, 2008; 88(4): 1567 - 1651.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
J. Song, X.-Q. Zhang, J. Wang, E. Cheskis, T. O. Chan, A. M. Feldman, A. L. Tucker, and J. Y. Cheung
Regulation of cardiac myocyte contractility by phospholemman: Na+/Ca2+ exchange versus Na+-K+-ATPase
Am J Physiol Heart Circ Physiol, October 1, 2008; 295(4): H1615 - H1625.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
A. L. Tucker, J. Song, X.-Q. Zhang, J. Wang, B. A. Ahlers, L. L. Carl, J. P. Mounsey, J. R. Moorman, L. I. Rothblum, and J. Y. Cheung
Altered contractility and [Ca2+]i homeostasis in phospholemman-deficient murine myocytes: role of Na+/Ca2+ exchange
Am J Physiol Heart Circ Physiol, November 1, 2006; 291(5): H2199 - H2209.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
X.-Q. Zhang, J. R. Moorman, B. A. Ahlers, L. L. Carl, D. E. Lake, J. Song, J. P. Mounsey, A. L. Tucker, Y.-m. Chan, L. I. Rothblum, et al.
Phospholemman overexpression inhibits Na+-K+-ATPase in adult rat cardiac myocytes: relevance to decreased Na+ pump activity in postinfarction myocytes
J Appl Physiol, January 1, 2006; 100(1): 212 - 220.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
C. A. Emter, S. A. McCune, G. C. Sparagna, M. J. Radin, and R. L. Moore
Low-intensity exercise training delays onset of decompensated heart failure in spontaneously hypertensive heart failure rats
Am J Physiol Heart Circ Physiol, November 1, 2005; 289(5): H2030 - H2038.
[Abstract] [Full Text] [PDF]

Home page
 Cardiovasc ResHome page
H. Reuter, C. Pott, J. I. Goldhaber, S. A. Henderson, K. D. Philipson, and R. H.G. Schwinger
Na+-Ca2+exchange in the regulation of cardiac excitation-contraction coupling
Cardiovasc Res, August 1, 2005; 67(2): 198 - 207.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
B. A. Ahlers, J. Song, J. Wang, X.-Q. Zhang, L. L. Carl, G. M. Tadros, L. I. Rothblum, and J. Y. Cheung
Effects of sarcoplasmic reticulum Ca2+-ATPase overexpression in postinfarction rat myocytes
J Appl Physiol, June 1, 2005; 98(6): 2169 - 2176.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
J. Bokenes, I. Sjaastad, and O. M. Sejersted
Artifactual contractions triggered by field stimulation of cardiomyocytes
J Appl Physiol, May 1, 2005; 98(5): 1712 - 1719.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
J. Song, X.-Q. Zhang, B. A. Ahlers, L. L. Carl, J. Wang, L. I. Rothblum, R. C. Stahl, J. P. Mounsey, A. L. Tucker, J. R. Moorman, et al.
Serine 68 of phospholemman is critical in modulation of contractility, [Ca2+]i transients, and Na+/Ca2+ exchange in adult rat cardiac myocytes
Am J Physiol Heart Circ Physiol, May 1, 2005; 288(5): H2342 - H2354.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
J. Song, X.-Q. Zhang, J. Wang, L. L. Carl, B. A. Ahlers, L. I. Rothblum, and J. Y. Cheung
Sprint training improves contractility in postinfarction rat myocytes: role of Na+/Ca2+ exchange
J Appl Physiol, August 1, 2004; 97(2): 484 - 490.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
M. A. Mirza, X.-Q. Zhang, B. A. Ahlers, A. Qureshi, L. L. Carl, J. Song, A. L. Tucker, J. P. Mounsey, J. R. Moorman, L. I. Rothblum, et al.
Effects of phospholemman downregulation on contractility and [Ca2+]i transients in adult rat cardiac myocytes
Am J Physiol Heart Circ Physiol, April 1, 2004; 286(4): H1322 - H1330.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
C. I. Spencer and J. S. K. Sham
Effects of Na+/Ca2+ exchange induced by SR Ca2+ release on action potentials and afterdepolarizations in guinea pig ventricular myocytes
Am J Physiol Heart Circ Physiol, December 1, 2003; 285(6): H2552 - H2562.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
L. J. Heller, D. E. Mohrman, J. A. Smith, and K. B. Wallace
Multitrack system for superfusing isolated cardiac myocytes
Am J Physiol Heart Circ Physiol, May 1, 2003; 284(5): H1872 - H1878.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
X.-Q. Zhang, A. Qureshi, J. Song, L. L. Carl, Q. Tian, R. C. Stahl, D. J. Carey, L. I. Rothblum, and J. Y. Cheung
Phospholemman modulates Na+/Ca2+ exchange in adult rat cardiac myocytes
Am J Physiol Heart Circ Physiol, January 1, 2003; 284(1): H225 - H233.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
X.-Q. Zhang, J. Song, A. Qureshi, L. I. Rothblum, L. L. Carl, Q. Tian, and J. Y. Cheung
Rescue of contractile abnormalities by Na+/Ca2+ exchanger overexpression in postinfarction rat myocytes
J Appl Physiol, December 1, 2002; 93(6): 1925 - 1931.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 1976 by the American Physiological Society.