AJP - Heart Calcium Transients and Cell-Sarcomere
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
 QUICK SEARCH:   [advanced]


     


Am J Physiol Heart Circ Physiol (March 25, 2005). doi:10.1152/ajpheart.01227.2004
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
289/2/H801    most recent
01227.2004v1
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 PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Korte, F. S.
Right arrow Articles by McDonald, K. S
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Korte, F. S.
Right arrow Articles by McDonald, K. S
Submitted on December 7, 2004
Accepted on March 24, 2005

Power output is linearly related to myosin heavy chain content in rat skinned myocytes and isolated working hearts

F. Steven Korte1, Todd J Herron1, Michael J Rovetto1, and Kerry S McDonald1*

1 Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA

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

The amount of work the heart can perform during ejection is governed by the inherent contractile properties of individual myocytes. One way to alter contractile properties is to alter contractile proteins such as myosin heavy chain (MyHC), which is known to demonstrate isoform plasticity in response to disease states. The purpose of this study was to examine myocyte functionality over the complete range of MyHC expression in the heart, from 100% {alpha}-MyHC to 100% {beta}-MyHC using euthyroid and hypothyroid rats. Peak power output in skinned cardiac myocytes decreased as a nearly linear function of {beta}-MyHC expression during maximal (r2 = 0.82, n = 44) and submaximal (r2 = 0.82, n = 31) Ca2+ activation. To determine if single myocyte function translated to the level of the whole heart, power output was measured in working heart preparations expressing varied ratios of MyHC. Left ventricular power output of isolated working heart preparations also decreased as a linear function of increasing {beta}-MyHC expression (r2 = 0.82, n = 34). These results demonstrate that power output is highly dependent on MyHC expression in single myocytes and this translates to the performance of working left ventricles.







HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 1977 by the American Physiological Society.