Contractility of permeabilized rat vastus intermedius muscle fibres following high-fat, high-sucrose diet consumption.

Autor:	Smith IC; Human Performance Lab, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada., Ostertag C; Human Performance Lab, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada., O'Reilly JJ; Human Performance Lab, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada., Rios JL; Human Performance Lab, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.; Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht, the Netherlands., Klancic T; Human Performance Lab, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada., MacDonald GZ; Human Performance Lab, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada., Collins KH; Human Performance Lab, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada., Reimer RA; Human Performance Lab, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.; Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada., Herzog W; Human Performance Lab, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.; Biomechanics Laboratory, School of Sports, Federal University of Santa Catarina, Florianopolis, SC, Brazil.
Jazyk:	angličtina
Zdroj:	Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme [Appl Physiol Nutr Metab] 2021 Nov; Vol. 46 (11), pp. 1389-1399. Date of Electronic Publication: 2021 Jun 17.
DOI:	10.1139/apnm-2021-0238
Abstrakt:	Obesity is a worldwide health concern associated with impaired physical function. It is not clear if contractile protein dysfunction contributes to the impairment of muscle function observed with obesity. The purpose of this study was to examine if diet-induced obesity affects contractile function of chemically permeabilized vastus intermedius fibres of male Sprague-Dawley rats expressing fast myosin heavy chain (MHC) IIa or slow MHC I. Rats consumed either a high-fat, high sucrose (HFHS) diet or a standard (CHOW) diet beginning as either weanlings (7-week duration: WEAN 7 cohort, or 14-week duration: WEAN 14 cohort) or young adults (12-week duration: ADULT 12 cohort, 24-week duration: ADULT 24 cohort). HFHS-fed rats had higher ( P < 0.05) whole-body adiposity (derived from dual-energy X-ray absorptiometry) than CHOW-fed rats in all cohorts. Relative to CHOW diet groups, the HFHS diet was associated with impaired force production in ( a ) MHC I fibres in the ADULT 24 cohort; and ( b ) MHC IIa fibres in the ADULT 12 and ADULT 24 cohorts combined. However, the HFHS diet did not significantly affect the Ca 2+ -sensitivity of force production, unloaded shortening velocity, or ratio of active force to active stiffness in any cohort. We conclude that diet-induced obesity can impair force output of permeabilized muscle fibres of adult rats. Novelty: We assessed contractile function of permeabilized skeletal muscle fibres in a rat model of diet-induced obesity. The high-fat, high-sucrose diet was associated with impaired force output of fibres expressing MHC I or MHC IIa in some cohorts of rats. Other measures of contractile function were not significantly affected by diet.
Databáze:	MEDLINE
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