Influence of temperature on mechanics and energetics of muscle contraction.
Results gleaned from use of temperature as a probe to study skeletal muscle performance and mechanisms of activation and contraction are reviewed. Steady-state and non-steady-state responses to changes in temperature are considered. Temperature sensitivities, Q10 values, of mechanical and energetic parameters range from nearly 1 to greater than 5 in frog skeletal muscle. Factors that are less temperature sensitive (Q10 less than or equal to 1.5) are peak tetanic force, instantaneous stiffness, curvature of force-velocity relation, magnitude of labile heat, and mechanical efficiency. Rates with intermediate temperature sensitivities (Q10 greater than 2 but less than 3) include rate of isometric force development, maximum shortening velocity, and relaxation from a brief tetanus. Rates with high temperature sensitivities (Q10 greater than 3) include cross-bridge turnover during an isometric tetanus, isometric economy, maximum power output, Ca2+ sequestration by sarcoplasmic reticulum, relaxation from a prolonged tetanus, and recovery metabolism. The observation that the Q10 for relaxation rate depends on tetanic duration can be explained in terms of the possible role of parvalbumin as a soluble relaxing factor.
Department of Physiology, Ohio State University, Columbus 43210.
J A
JA
Rall
R C
RC
Woledge
D000818:Animals; D001696:Biomechanical Phenomena; D004734:Energy Metabolism; D006706:Homeostasis; D006801:Humans; D007537:Isometric Contraction; D007551:Isotonic Contraction; D009119:Muscle Contraction / Q000502:physiology*; D013696:Temperature