AJP - Heart AJP: Endocrinology and Metabolism
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 276: H1167-H1171, 1999;
0363-6135/99 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
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 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 Google Scholar
Google Scholar
Right arrow Articles by Buck, S. H.
Right arrow Articles by Moss, R. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Buck, S. H.
Right arrow Articles by Moss, R. L.
Vol. 276, Issue 4, H1167-H1171, April 1999

Altered kinetics of contraction of mouse atrial myocytes expressing ventricular myosin regulatory light chain

Scott H. Buck1, Patrick J. Konyn1, Joseph Palermo2, Jeffrey Robbins2, and Richard L. Moss3

Departments of 1 Pediatrics and 3 Physiology, University of Wisconsin Medical School, Madison, Wisconsin 53706; and 2 Division of Molecular Cardiovascular Biology, Children's Hospital Research Foundation, Cincinnati, Ohio 45229

To investigate the role of myosin regulatory light chain isoforms as a determinant of the kinetics of cardiac contraction, unloaded shortening velocity was determined by the slack-test method in skinned wild-type murine atrial cells and transgenic cells expressing ventricular regulatory light chain (MLC2v). Transgenic mice were generated using a 4.5-kb fragment of the murine alpha -myosin heavy chain promoter to drive high levels of MLC2v expression in the atrium. Velocity of unloaded shortening was determined at 15°C in maximally activating Ca2+ solution (pCa 4.5) containing (in mmol/l) 7 EGTA, 1 free Mg2+, 4 MgATP, 14.5 creatine phosphate, and 20 imidazole (ionic strength 180 mmol/l, pH 7.0). Compared with the wild type (n = 10), the unloaded shortening velocity of MLC2v-expressing transgenic murine atrial cells (n = 10) was significantly greater (3.88 ± 1.19 vs. 2.51 ± 1.08 muscle lengths/s, P < 0.05). These results provide evidence that myosin light chain 2 regulates cross-bridge cycling rate. The faster rate of cycling in the presence of MLC2v suggests that the MLC2v isoform may contribute to the greater power-generating capabilities of the ventricle compared with the atrium.

myofilaments; isoforms; shortening velocity; transgenic


This article has been cited by other articles:


Home page
 Am. J. Physiol. Cell Physiol.Home page
S. Zhong and L. V. Thompson
The roles of myosin ATPase activity and myosin light chain relative content in the slowing of type IIB fibers with hindlimb unweighting in rats
Am J Physiol Cell Physiol, August 1, 2007; 293(2): C723 - C728.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. GenomicsHome page
M. D. Fischer, J. R. Gorospe, E. Felder, S. Bogdanovich, F. Pedrosa-Domellof, R. S. Ahima, N. A. Rubinstein, E. P. Hoffman, and T. S. Khurana
Expression profiling reveals metabolic and structural components of extraocular muscles
Physiol Genomics, May 10, 2002; 9(2): 71 - 84.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
A. Sanbe, J. Gulick, E. Hayes, D. Warshaw, H. Osinska, C.-B. Chan, R. Klevitsky, and J. Robbins
Myosin light chain replacement in the heart
Am J Physiol Heart Circ Physiol, September 1, 2000; 279(3): H1355 - H1364.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online