The Contribution of Myofibrillar Properties to the Sarcomere Length-Force Relationship of Cardiac Muscle

1988 ◽  
pp. 1-17 ◽  
Author(s):  
J. C. Kentish ◽  
H. E. D. J. Ter Keurs ◽  
D. G. Allen
Keyword(s):  
Cardiac Muscle ◽  
Sarcomere Length ◽  
Relationship Of ◽  
Force Relationship

Mean sarcomere length-force relationship of rat muscle fibre bundles

1995 ◽  
Vol 28 (1) ◽  
pp. 83-87 ◽  
Author(s):  
C.J. Zuurbier ◽  
J.W. Heslinga ◽  
M.B.E. Lee-de Groot ◽  
W.J. Van der Laarse
Keyword(s):  
Muscle Fibre ◽  
Sarcomere Length ◽  
Fibre Bundles ◽  
Rat Muscle ◽  
Relationship Of ◽  
Force Relationship

Morphological Basis of the Disparity Between Muscle Length and Sarcomere Length in the Myocardium

1973 ◽  
Vol 31 ◽  
pp. 422-423
Author(s):  
G.E. Adomian ◽  
L. Chuck ◽  
W.W. Pannley
Keyword(s):  
Cardiac Muscle ◽  
Sarcomere Length ◽  
Muscle Length ◽  
Contractile Force ◽  
Direct Function ◽  
Morphological Basis ◽  
Tension Curve

Sonnenblick, et al, have shown that sarcomeres change length as a function of cardiac muscle length along the ascending portion of the length-tension curve. This allows the contractile force to be expressed as a direct function of sarcomere length. Below L max, muscle length is directly related to sarcomere length at lengths greater than 85% of optimum. However, beyond the apex of the tension-length curve, i.e. L max, a disparity occurs between cardiac muscle length and sarcomere length. To account for this disproportionate increase in muscle length as sarcomere length remains relatively stable, the concept of fiber slippage was suggested as a plausible explanation. These observations have subsequently been extended to the intact ventricle.

Cooperative activation in cardiac muscle: impact of sarcomere length

2002 ◽  
Vol 282 (3) ◽  
pp. H1055-H1062 ◽  
Author(s):  
David P. Dobesh ◽  
John P. Konhilas ◽  
Pieter P. de Tombe
Keyword(s):  
Sarcomere Length ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Significant Function ◽  
Cardiac Myofilament ◽  
Data Points ◽  
On Line ◽  
The Impact ◽  
Cooperative Activation ◽  
Force Relationship

This study was undertaken to determine the impact of sarcomere length (SL) on the level of cooperative activation of the cardiac myofilament at physiological [Mg2+]. Active force development was measured in skinned rat cardiac trabeculae as a function of free [Ca2+] at five SLs (1.85–2.25 μm; 1 mM free [Mg2+]; 15°C). Only muscle preparations with minimal force rundown during the entire protocol were included in the analysis (average 7.2 ± 1.7%). Median SL was measured by on-line computer video micrometry and controlled within 0.01 μm. Care was taken to ensure a sufficient number of data points in the steep portion of the [Ca2+]-force relationship at every SL to allow for accurate fit of the data to a modified Hill equation. Multiple linear regression analysis of the fit parameters revealed that both maximum, Ca2+-saturated force and Ca2+sensitivity were a significant function of SL ( P < 0.001), whereas the level of cooperativity did not depend on SL ( P = 0.2). Further analysis of the [Ca2+]-force relationships revealed a marked asymmetry that, also, was not affected by SL ( P = 0.2–0.6). Finally, we found that the level of cooperativity in isolated skinned myocardium was comparable to that reported for intact, nonskinned myocardium. Our results suggest that an increase in SL induces an increase in the Ca2+ responsiveness of the cardiac sarcomere without affecting the level of cooperativity.

The Frank-Starling mechanism is not mediated by changes in rate of cross-bridge detachment

1997 ◽  
Vol 273 (5) ◽  
pp. H2428-H2435 ◽  
Author(s):  
Thomas Wannenburg ◽  
Paul M. L. Janssen ◽  
Dongsheng Fan ◽  
Pieter P. De Tombe
Keyword(s):  
Cardiac Muscle ◽  
Maximum Rate ◽  
Sarcomere Length ◽  
Myosin Head ◽  
Isometric Force ◽  
Force Development ◽  
Cross Bridge ◽  
Average Slope ◽  
The Cross ◽  
Kinetics Of

We tested the hypothesis that the Frank-Starling relationship is mediated by changes in the rate of cross-bridge detachment in cardiac muscle. We simultaneously measured isometric force development and the rate of ATP consumption at various levels of Ca2+ activation in skinned rat cardiac trabecular muscles at three sarcomere lengths (2.0, 2.1, and 2.2 μm). The maximum rate of ATP consumption was 1.5 nmol ⋅ s−1 ⋅ μl fiber vol−1, which represents an estimated adenosinetriphosphatase (ATPase) rate of ∼10 s−1 per myosin head at 24°C. The rate of ATP consumption was tightly and linearly coupled to the level of isometric force development, and changes in sarcomere length had no effect on the slope of the force-ATPase relationships. The average slope of the force-ATPase relationships was 15.5 pmol ⋅ mN−1 ⋅ mm−1. These results suggest that the mechanisms that underlie the Frank-Starling relationship in cardiac muscle do not involve changes in the kinetics of the apparent detachment step in the cross-bridge cycle.

scholarly journals Engineered Thin Filament Mutations to Study the Sarcomere Length Dependence of Cardiac Muscle Contractility

2018 ◽  
Vol 114 (3) ◽  
pp. 313a-314a
Author(s):  
Joseph D. Powers ◽  
Farid Moussavi-Harami ◽  
Jil C. Tardiff ◽  
Jennifer Davis ◽  
Michael Regnier
Keyword(s):  
Cardiac Muscle ◽  
Thin Filament ◽  
Sarcomere Length ◽  
Muscle Contractility ◽  
Length Dependence

scholarly journals Inherent Force-Dependent Properties of β -Cardiac Myosin Contribute to the Force-Velocity Relationship of Cardiac Muscle

2014 ◽  
Vol 107 (12) ◽  
pp. L41-L44 ◽  
Author(s):  
Michael J. Greenberg ◽  
Henry Shuman ◽  
E. Michael Ostap
Keyword(s):  
Cardiac Muscle ◽  
Cardiac Myosin ◽  
Velocity Relationship ◽  
Force Velocity ◽  
Relationship Of

216 Experimental Evaluation of the Torque-Bolt Force Relationship of Wheel Bolts for Large Vehicles

2009 ◽  
Vol 2009.84 (0) ◽  
pp. _2-16_
Author(s):  
Yoshinori FUKUMAN ◽  
Toshimichi FUKUOKA ◽  
Masataka NOMURA
Keyword(s):  
Experimental Evaluation ◽  
Relationship Of ◽  
Force Relationship
Sign in / Sign up

Export Citation Format

Share Document