Effects of ageing and gender on contractile properties in human skeletal muscle and single fibres
2007 (English)In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 190, no 3, 229-241 p.Article in journal (Refereed) Published
Aim: The objective of this study is to improve our understanding of the mechanisms underlying the ageing- and gender-related muscle weakness.
Methods: Ageing- and gender-related differences in regulation of muscle contraction have been studied in knee-extensor muscles at the whole muscle and single muscle fibre levels in young and old sedentary men and women. In vivo knee-extensor muscle function was measured at slow (30° s−1) and faster (180 ° s−1) speeds of movement. Maximum velocity of unloaded shortening (V0) and maximum force normalized to cross-sectional area (CSA) [specific tension (ST)] were measured in single 'skinned' skeletal muscle fibre segments.
Results: Significant ageing- and gender-related differences were observed in muscle torque. A 33–55% ageing-related decline (P < 0.001) in maximum torque was observed irrespective of gender. At the single muscle fibre level, the ageing-related decline in knee-extensor muscle function was accompanied by a 20–28% decline in ST in muscle fibres expressing the type I MyHC isoform in both men and women, and a 29% decline in type IIa muscle fibre CSA, but the decreased fast-twitch fibre size was restricted to the men. Furthermore, in both men and women, V0 decreased in muscle cells expressing the type I and IIa MyHC isoforms.
Conclusion: The present results provide evidence of specific ageing- and gender-related differences in regulation of muscle contraction at the cellular level. It is suggested that these cellular changes have a significant impact on muscle function and the ageing-related motor handicap.
Place, publisher, year, edition, pages
2007. Vol. 190, no 3, 229-241 p.
maximum velocity of unloaded shortening, muscle mass, skinned fibres, slack test, specific tension, torque-velocity
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-97417DOI: 10.1111/j.1748-1716.2007.01699.xISI: 000247318600006OAI: oai:DiVA.org:uu-97417DiVA: diva2:172361