Journal of Applied Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 93: 1925-1931, 2002. First published August 16, 2002; doi:10.1152/japplphysiol.00583.2002
8750-7587/02 $5.00
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow All Versions of this Article:
93/6/1925    most recent
00583.2002v1
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI 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 ISI Web of Science (5)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zhang, X.-Q.
Right arrow Articles by Cheung, J. Y.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhang, X.-Q.
Right arrow Articles by Cheung, J. Y.
Vol. 93, Issue 6, 1925-1931, December 2002

Rescue of contractile abnormalities by Na+/Ca2+ exchanger overexpression in postinfarction rat myocytes

Xue-Qian Zhang1, Jianliang Song1, Anwer Qureshi1,2, Lawrence I. Rothblum1, Lois L. Carl1, Qiang Tian1, and Joseph Y. Cheung1,2

1 Weis Center for Research, and 2 Department of Medicine, Geisinger Medical Center, Danville, Pennsylvania 17822

Previous studies on myocytes isolated from rat hearts 3 wk after myocardial infarction (MI) demonstrated increased cell length, reduced Na+/Ca2+ exchange (NCX1) activity, altered contractility, and intracellular Ca2+ concentration ([Ca2+]i) transients. In the present study, we investigated whether NCX1 overexpression in MI myocytes would restore contraction and [Ca2+]i transients to normal. When myocytes were placed in culture under continued electrical-field stimulation conditions, differences in contraction amplitudes and cell lengths between sham and MI myocytes were preserved for at least 48 h. Infection of both sham and MI myocytes by adenovirus expressing green fluorescent protein resulted in >95% infection, as evidenced by green fluorescent protein fluorescence, but contraction amplitudes at 6-, 24-, and 48-h postinfection were not affected. NCX1 overexpression in MI myocytes resulted in lower diastolic [Ca2+]i levels at all extracellular Ca2+ concentrations ([Ca2+]o) examined, suggesting enhanced forward NCX1 activity. At 5 mM [Ca2+]o, subnormal contraction and [Ca2+]i transient amplitudes in MI myocytes (compared with sham myocytes) were restored toward normal levels by overexpressing NCX1. At 0.6 mM [Ca2+]o, supranormal contraction and [Ca2+]i transient amplitudes in MI myocytes (compared with sham myocytes) were lowered by NCX1 overexpression. We conclude that overexpression of NCX1 in MI myocytes was effective in improving contractile dysfunction, most likely because of enhancement of both Ca2+ efflux and influx during a cardiac cycle. We suggest that decreased NCX1 activity may play an important role in contractile abnormalities in postinfarction myocytes.

excitation-contraction coupling; fura 2; primary cardiac myocyte culture


This article has been cited by other articles:


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
 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
 Am. J. Physiol. Heart Circ. Physiol.Home page
Q. Shao, B. Ren, V. Elimban, P. S. Tappia, N. Takeda, and N. S. Dhalla
Modification of sarcolemmal Na+-K+-ATPase and Na+/Ca2+ exchanger expression in heart failure by blockade of renin-angiotensin system
Am J Physiol Heart Circ Physiol, June 1, 2005; 288(6): H2637 - H2646.
[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 HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online