title: The beneficial effect of myostatin deficiency on maximal muscle force and power is attenuated with age.
abstract: The prolonged effect of myostatin deficiency on muscle performance in knockout mice has as yet been only poorly investigated. We have demonstrated that absolute maximal force is increased in 6-month old female and male knockout mice and 2-year old female knockout mice as compared to age- and sex-matched wildtype mice. Similarly, absolute maximal power is increased by myostatin deficiency in 6-month old female and male knockout mice but not in 2-year old female knockout mice. The increases we observed were greater in 6-month old female than in male knockout mice and can primarily result from muscle hypertrophy. In contrast, fatigue resistance was decreased in 6-month old knockout mice of both sexes as compared to age- and sex-matched wildtype mice. Moreover, in contrast to 2-year old female wildtype mice, aging in 2-year old knockout mice reduced absolute maximal force and power of both sexes as compared to their younger counterparts, although muscle weight did not change. These age-related decreases were lower in 2-year old female than in 2-year old male knockout mice. Together these results suggest that the beneficial effect of myostatin deficiency on absolute maximal force and power is greater in young (versus old) mice and female (versus male) mice. Most of these effects of myostatin deficiency are related neither to changes in the concentration of myofibrillar proteins nor to the slow to fast fiber type transition.
authors.affiliation: Université Pierre et Marie Curie-Paris6, Sorbonne Universités, UMR S794, INSERM, U974, CNRS UMR7215, Institut de Myologie, Paris F-75013, France.
authors.forename: E
authors.initials: E
authors.lastname: Schirwis
authors.forename: O
authors.initials: O
authors.lastname: Agbulut
authors.forename: Nathalie
authors.initials: N
authors.lastname: Vadrot
authors.forename: E
authors.initials: E
authors.lastname: Mouisel
authors.forename: C
authors.initials: C
authors.lastname: Hourdé
authors.forename: A
authors.initials: A
authors.lastname: Bonnieu
authors.forename: G
authors.initials: G
authors.lastname: Butler-Browne
authors.forename: H
authors.initials: H
authors.lastname: Amthor
authors.forename: A
authors.initials: A
authors.lastname: Ferry
mesh_terms: D000367:Age Factors; D000375:Aging / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009119:Muscle Contraction; D018763:Muscle Fatigue; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000378:metabolism*; D055435:Myostatin / Q000172:deficiency* / Q000235:genetics; D012737:Sex Factors
chemical_list: C525912:Mstn protein, mouse; D055435:Myostatin