CoChat
Sign Up
Cited by 117Cardiomyopathy and Myosin StudiesCardiovascular Function and Risk FactorsCardiac electrophysiology and arrhythmias

Impact of β-myosin heavy chain isoform expression on cross-bridge cycling kinetics

Rundell, Veronica L. M., Manaves, Vlasios, Martin, Anne F., de Tombe, Pieter P.·2005·American Journal of Physiology-Heart and Circulatory Physiology
DOI 10.1152/ajpheart.00407.2004
Open this paper in CoChat — free account

Abstract

Myosin heavy chain (MHC) isoforms α and β have intrinsically different ATP hydrolysis activities (ATPase) and therefore cross-bridge cycling rates in solution. There is considerable evidence of altered MHC expression in rodent cardiac disease models; however, the effect of incremental β-MHC expression over a wide range on the rate of high-strain, isometric cross-bridge cycling is yet to be ascertained. We treated male rats with 6-propyl-2-thiouracil (PTU; 0.8 g/l in drinking water) for short intervals (6, 11, 16, and 21 days) to generate cardiac MHC patterns in transition from predominantly α-MHC to predominantly β-MHC. Steady-state calcium-dependent tension development and tension-dependent ATP consumption (tension cost; proportional to cross-bridge cycling) were measured in chemically permeabilized (skinned) right ventricular muscles at 20°C. To assess dynamic cross-bridge cycling kinetics, the rate of force redevelopment ( k tr) was determined after rapid release-restretch of fully activated muscles. MHC isoform content in each experimental muscle was measured by SDS-PAGE and densitometry. α-MHC content decreased significantly and progressively with length of PTU treatment [68 ± 5%, 58 ± 4%, 37 ± 4%, and 27 ± 6% for 6, 11, 16, and 21 days, respectively; P < 0.001 (ANOVA)]. Tension cost decreased, linearly, with decreased α-MHC content [6.7 ± 0.4, 5.6 ± 0.5, 4.0 ± 0.4, and 3.9 ± 0.3 ATPase/tension for 6, 11, 16, and 21 days, respectively; P < 0.001 (ANOVA)]. Likewise, k tr was significantly and progressively depressed with length of PTU treatment [11.1 ± 0.6, 9.1 ± 0.5, 8.2 ± 0.7, and 6.2 ± 0.3 s−1 for 6, 11, 16, and 21 days, respectively; P < 0.05 (ANOVA)] Thus cross-bridge cycling, under high strain, for α-MHC is three times higher than for β-MHC. Furthermore, under isometric conditions, α-MHC and β-MHC cross bridges hydrolyze ATP independently of one another.

Integrity signals

Registry

Crossref · 10.1152/ajpheart.00407.2004

Cites

41 of 41 references verified0 citation errors · 0 not checkable

Statistics

Recomputing p-values needs the paper’s full text.

Claims the paper makes

This paper’s full text isn’t openly available, so its claims and self-check weren’t run. The registry and citation checks still apply.

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Related

Authors
Rundell, V. L. M., Manaves, V., Martin, A. F., & de Tombe, P. P.
Affiliations
University of Illinois Chicago (US)
Venue
American Journal of Physiology-Heart and Circulatory Physiology
Publisher
American Physiological Society
Published
2005-02
Volume
288
Issue
2
Pages
H896-H903
ISSN
  • 0363-6135 (ISSN-L)
  • 1522-1539
DOI
10.1152/ajpheart.00407.2004
OpenAlex
W2131022985
Cited by
117
References
41
Citations by year
2025: 5 · 2023: 5 · 2022: 1 · 2021: 4 · 2020: 1 · 2019: 6 · 2018: 8 · 2017: 5 · 2016: 7 · 2015: 7 · 2014: 9 · 2013: 6 · 2012: 9
FWCI
5.46
Type
journal article
Language
en
Open access
closed
Locations
  • American Journal of Physiology-Heart and Circulatory Physiology (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • National Institutes of Health (5t32hl072742-10)
  • National Heart, Lung, and Blood Institute (HL/DK-R01-63704, R01HL064942, T32HL07692, HL-P0162426, HL 64942, T32-HL-072742, T32HL007692, P01HL062426)
Topics
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Cardiomyopathy and Myosin Studies
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Cardiovascular Function and Risk Factors
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Cardiac electrophysiology and arrhythmias
Keywords
beta-myosin heavy chain, myosin heavy chain isoforms, alpha-myosin heavy chain, 6-n-propylthiouracil, ATPase activity, cardiac contractility, cardiac disease models, right ventricle
MeSH terms
Adenosine Triphosphate, Animals, Hypothyroidism, Isomerism, Kinetics, Male, Myocardial Contraction, Propylthiouracil, Rats, Inbred Lew, Antithyroid Agents, Myosin Heavy Chains, Ventricular Myosins, Myocytes, Cardiac, Rats

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review