caa a22 4500 605513945 CHVBK 20210128100702.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00360-014-0872-6 doi (NATIONALLICENCE)springer-10.1007/s00360-014-0872-6 Regional thermal specialisation in a mammal: temperature affects power output of core muscle more than that of peripheral muscle in adult mice ( Mus musculus ) [Elektronische Daten] [Rob James, Jason Tallis, Michael Angilletta Jr.] In endotherms, such as mammals and birds, internal organs can specialise to function within a narrow thermal range. Consequently, these organs should become more sensitive to changes in body temperature. Yet, organs at the periphery of the body still experience considerable fluctuations in temperature, which could select for lower thermal sensitivity. We hypothesised that the performance of soleus muscle taken from the leg would depend less on temperature than would the performance of diaphragm muscle taken from the body core. Soleus and diaphragm muscles were isolated from mice and subjected to isometric and work-loop studies to analyse mechanical performance at temperatures between 15 and 40°C. Across this thermal range, soleus muscle took longer to generate isometric force and longer to relax, and tended to produce greater normalised maximal force (stress) than did diaphragm muscle. The time required to produce half of maximal force during isometric tetanus and the time required to relax half of maximal force were both more sensitive to temperature in soleus than they were in diaphragm. However, thermal sensitivities of maximal force during isometric tetani were similar for both muscles. Consistent with our hypothesis, power output (the product of speed and force) was greater in magnitude and more thermally sensitive in diaphragm than it was in soleus. Our findings, when combined with previous observations of muscles from regionally endothermic fish, suggest that endothermy influences the thermal sensitivities of power output in core and peripheral muscles. Springer-Verlag Berlin Heidelberg, 2014 Endotherm nationallicence Force nationallicence Power nationallicence Temperature nationallicence Tetanus nationallicence Thermal sensitivity nationallicence James Rob Department of Applied Sciences and Health, Coventry University, CV1 5FB, Coventry, UK aut Tallis Jason Department of Applied Sciences and Health, Coventry University, CV1 5FB, Coventry, UK aut Angilletta Jr. Michael School of Life Sciences, Arizona State University, 85287, Tempe, AZ, USA aut Journal of Comparative Physiology B Springer Berlin Heidelberg 185/1(2015-01-01), 135-142 0174-1578 185:1<135 2015 185 360 https://doi.org/10.1007/s00360-014-0872-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00360-014-0872-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- James Rob Department of Applied Sciences and Health, Coventry University, CV1 5FB, Coventry, UK aut NATIONALLICENCE 700 1- Tallis Jason Department of Applied Sciences and Health, Coventry University, CV1 5FB, Coventry, UK aut NATIONALLICENCE 700 1- Angilletta Jr Michael School of Life Sciences, Arizona State University, 85287, Tempe, AZ, USA aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer Berlin Heidelberg 185/1(2015-01-01), 135-142 0174-1578 185:1<135 2015 185 360