AJP - Heart AJP: Advances in Physiology Education
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 279: H779-H790, 2000;
0363-6135/00 $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 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 (31)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wannenburg, T.
Right arrow Articles by De Tombe, P. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wannenburg, T.
Right arrow Articles by De Tombe, P. P.
Vol. 279, Issue 2, H779-H790, August 2000

Cross-bridge kinetics in rat myocardium: effect of sarcomere length and calcium activation

Thomas Wannenburg, Gerardus H. Heijne, Jeroen H. Geerdink, Hendrik W. Van den Dool, Paul M. L. Janssen, and Pieter P. De Tombe

Section on Cardiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157

We tested the hypotheses that Ca2+ concentration ([Ca2+]) and sarcomere length (SL) modulate force development via graded effects on cross-bridge kinetics in chemically permeabilized rat cardiac trabeculae. Using sinusoidal length perturbations, we derived the transfer functions of stiffness over a range of [Ca2+] at a constant SL of 2.1 µm (n = 8) and at SL of 2.0, 2.1, and 2.2 µm (n = 4). We found that changes in SL affected only the magnitude of stiffness, whereas [Ca2+] affected the magnitude and phase-frequency relations. The data were fit to complex functions of two exponential processes. The characteristic frequencies (b and c) of these processes are indexes of cross-bridge kinetics, with b relating to cross-bridge attachment to and c to detachment from certain non-force-generating states. Both were significantly affected by [Ca2+], with an increase in b and c of 140 and 44%, respectively, over the range of [Ca2+] studied (P < 0.01). In contrast, SL had no effect on the characteristic frequencies (P > 0.6). We conclude that Ca2+ activation modulates force development in rat myocardium, at least in part, via a graded effect on cross-bridge kinetics, whereas SL effects are mediated mainly by recruitment of cross bridges.

sinusoidal perturbation; dynamic transfer function of stiffness; myocardial cross-bridge mechanics; skinned fibers


This article has been cited by other articles:


Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
M. Chandra, M. L. Tschirgi, S. J. Ford, B. K. Slinker, and K. B. Campbell
Interaction between myosin heavy chain and troponin isoforms modulate cardiac myofiber contractile dynamics
Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2007; 293(4): R1595 - R1607.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
I. F. Edes, D. Czuriga, G. Csanyi, S. Chlopicki, F. A. Recchia, A. Borbely, Z. Galajda, I. Edes, J. van der Velden, G. J. M. Stienen, et al.
Rate of tension redevelopment is not modulated by sarcomere length in permeabilized human, murine, and porcine cardiomyocytes
Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R20 - R29.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
W. D. Gao, T. Dai, and D. Nyhan
Increased cross-bridge cycling rate in stunned myocardium
Am J Physiol Heart Circ Physiol, February 1, 2006; 290(2): H886 - H893.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
K. B. Campbell, Y. Wu, A. M. Simpson, R. D. Kirkpatrick, S. G. Shroff, H. L. Granzier, and B. K. Slinker
Dynamic myocardial contractile parameters from left ventricular pressure-volume measurements
Am J Physiol Heart Circ Physiol, July 1, 2005; 289(1): H114 - H130.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
Y. Yaniv, R. Sivan, and A. Landesberg
Analysis of hystereses in force length and force calcium relations
Am J Physiol Heart Circ Physiol, January 1, 2005; 288(1): H389 - H399.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
K. B. Campbell, M. Chandra, R. D. Kirkpatrick, B. K. Slinker, and W. C. Hunter
Interpreting cardiac muscle force-length dynamics using a novel functional model
Am J Physiol Heart Circ Physiol, April 1, 2004; 286(4): H1535 - H1545.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
C. Levy and A. Landesberg
Hystereses in the force-length relation and regulation of cross-bridge recruitment in tetanized rat trabeculae
Am J Physiol Heart Circ Physiol, January 1, 2004; 286(1): H434 - H441.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
D. Fatkin and R. M. Graham
Molecular Mechanisms of Inherited Cardiomyopathies
Physiol Rev, October 1, 2002; 82(4): 945 - 980.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
A. E. Bartunek, V. A. Claes, and P. R. Housmans
Effects of volatile anesthetics on elastic stiffness in isometrically contracting ferret ventricular myocardium
J Appl Physiol, June 1, 2002; 92(6): 2491 - 2500.
[Abstract] [Full Text] [PDF]


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