Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Unexplained enthalpy production in contracting skeletal muscles

E Homsher, C J Kean

    Federation Proceedings
    |February 1, 1982
    PubMed
    Summary

    Muscle contraction generates heat beyond high-energy phosphate splitting. Two additional heat sources were identified: Ca2+ redistribution and cross-bridge state changes during contraction, both reversed by ATP splitting.

    Related Concept Videos

    You might also read

    Related Articles

    Articles linked to this work by shared authors, journal, and citation graph.

    Sort by
    Same author

    Mechanical and kinetic effects of shortened tropomyosin reconstituted into myofibrils.

    Pflugers Archiv : European journal of physiology·2009
    Same author

    Contractile effects of the exchange of cardiac troponin for fast skeletal troponin in rabbit psoas single myofibrils.

    The Journal of physiology·2003
    Same author

    Regulatory proteins alter nucleotide binding to acto-myosin of sliding filaments in motility assays.

    Biophysical journal·2003
    Same author

    Modulation of myosin function by isoform-specific properties of Saccharomyces cerevisiae and muscle tropomyosins.

    The Journal of biological chemistry·2001
    Same author

    Skeletal and cardiac muscle contractile activation: tropomyosin "rocks and rolls".

    News in physiological sciences : an international journal of physiology produced jointly by the International Union of Physiological Sciences and the American Physiological Society·2001
    Same author

    Modulation of contractile activation in skeletal muscle by a calcium-insensitive troponin C mutant.

    The Journal of biological chemistry·2001

    Area of Science:

    • Muscle physiology
    • Bioenergetics
    • Biophysics

    Background:

    • Muscle contraction is primarily fueled by high-energy phosphate splitting.
    • The complete enthalpy production during muscle contraction is not fully explained by this process alone.

    Purpose of the Study:

    • To investigate additional sources of heat production during muscle contraction.
    • To test the hypothesis that observed enthalpy production is solely due to high-energy phosphate splitting.

    Main Methods:

    • Energy balance experiments were conducted on muscle tissue at 0°C.
    • Isometric tetanus and rapid shortening contractions were analyzed.

    Main Results:

    • Two sources of unexplained enthalpy production were identified during muscle contraction.
    • The first, ~25 mJ/g, occurred in the initial 5s of isometric tetanus and was independent of filament overlap, suggesting Ca2+ redistribution.
    • The second, 5-8 mJ/g, occurred during rapid filament sliding, possibly due to cross-bridge state redistribution.

    Conclusions:

    • Muscle contraction involves heat production beyond high-energy phosphate splitting.
    • Calcium ion redistribution and cross-bridge dynamics are significant contributors to muscle heat production.
    • These additional enthalpy productions are likely reversed by subsequent ATP hydrolysis.

    Related Experiment Videos