Force and power generating mechanism(s) in active muscle as revealed from temperature perturbation studies

KW Ranatunga

Research output: Contribution to journalArticle (Academic Journal)peer-review

23 Citations (Scopus)

Abstract

The basic characteristics of the process of force and power generation in active muscle that have emerged from temperature studies are examined. This is done by reviewing complementary findings from temperature-dependence studies and rapid temperature-jump (T-jump) experiments and from intact and skinned fast mammalian muscle fibres. In isometric muscle, a small T-jump leads to a characteristic rise in force showing that crossbridge force generation is endothermic (heat absorbed) and associated with increased entropy (disorder). The sensitivity of the T-jump force generation to added inorganic phosphate (Pi) indicates that a T-jump enhances an early step in the actomyosin (crossbridge) ATPase cycle before Pi-release. During muscle lengthening when steady force is increased, the T-jump force generation is inhibited. Conversely, during shortening when steady force is decreased, the T-jump force generation is enhanced in a velocity-dependent manner, showing that T-jump force generation is strain sensitive. Within the temperature range of ∼5–35◦C, the temperature dependence of steady active force is sigmoidal both in isometric and in shortening muscle. However, in shortening muscle, the endothermic character of force generation becomes more pronounced with increased velocity and this can, at least partly, account for the marked increase with warming of the mechanical power output of active muscle.
Translated title of the contributionForce and power generating mechanism(s) in active muscle as revealed from temperature perturbation studies
Original languageEnglish
Pages (from-to)3657 - 3670
Number of pages13
JournalJournal of Physiology
Volume588
DOIs
Publication statusPublished - Oct 2010

Fingerprint Dive into the research topics of 'Force and power generating mechanism(s) in active muscle as revealed from temperature perturbation studies'. Together they form a unique fingerprint.

Cite this