Age- and Gender-Related Changes in Contractile Properties of Non-Atrophied EDL Muscle

Chan, Stephen; Head, Stewart I.

doi:10.1371/journal.pone.0012345

Cited by 56 publications

(79 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is more likely that the use of older animals (26-28 months) in other studies than in our study (25 months) contributes to the discrepancy, as larger effects of aging on maximal muscle force are likely to be observed in the older the animal (Ballak et al 2014;Brooks and Faulkner 1988;Lynch et al 2001;McArdle et al 2004). Indeed, Chan and Head (2010) observed that even in 20-22-month-old mice, specific force was already reduced without significant muscle atrophy. Combination of the data of these studies with slightly older and younger mice than the ones used in the present study suggests that a reduction in muscle quality precedes a reduction in muscle mass.…”

Section: Discussionmentioning

confidence: 50%

Plantaris muscle weakness in old mice: relative contributions of changes in specific force, muscle mass, myofiber cross-sectional area, and number

Ballak

Degens

Busé-Pot

et al. 2014

AGE

View full text Add to dashboard Cite

The age-related decline in muscle function contributes to the movement limitations in daily life in old age. The age-related loss in muscle force is attributable to loss of myofibers, myofiber atrophy, and a reduction in specific force. The contribution of each of these determinants to muscle weakness in old age is, however, largely unknown. The objective of this study is to determine whether a loss in myofiber number, myofiber atrophy, and a reduction in specific muscle force contribute to the age-related loss of muscle force in 25-month-old mouse. Maximal isometric force of in situ m. plantaris of C57BL/6J male adult (9 months) and old (25 months) mice was determined and related to myofiber number, myofiber size, intramuscular connective tissue content, and proportion of denervated myofibers. Isometric maximal plantaris muscle force was 13 % lower in old than adult mice (0.97±0.05 N vs. 0.84±0.03 N; P<0.05). M. plantaris mass of old mice was not significantly smaller than that of adult mice. There was also no significant myofiber atrophy or myofiber loss. Specific muscle force of old mice was 25 % lower than that of adult mice (0.55±0.05 vs. 0.41± 0.03 N·mm −2 , P<0.01). In addition, with age, the proportion of type IIB myofibers decreased (43.6 vs. 38.4 %, respectively), while the connective tissue content increased (11.6 vs. 16.4 %, respectively). The agerelated reduction in maximal isometric plantaris muscle force in 25-month-old male C57BL/6J mice is mainly attributable to a reduction in specific force, which is for 5 % explicable by an age-related increase in connective tissue, rather than myofiber atrophy and myofiber loss.

show abstract

Section: Discussionmentioning

confidence: 50%

Plantaris muscle weakness in old mice: relative contributions of changes in specific force, muscle mass, myofiber cross-sectional area, and number

Ballak

Degens

Busé-Pot

et al. 2014

AGE

View full text Add to dashboard Cite

show abstract

“…The changes in the contractile profiles of EDL muscles have also been observed in young and healthy mice treated with a physiological dose of statin. Statins are often prescribed to elderly patients, who are often sarcopenic and undergo a gradual change toward a slow-myofiber phenotype [54, 55]. Would these changes in contractile properties be greater in patients with chronic conditions?…”

Section: Discussionmentioning

confidence: 99%

A short-term statin treatment changes the contractile properties of fast-twitch skeletal muscles

Piette

Dufresne

Frenette

2016

BMC Musculoskelet Disord

View full text Add to dashboard Cite

BackgroundCumulative evidence indicates that statins induce myotoxicity. However, the lack of understanding of how statins affect skeletal muscles at the structural, functional, and physiological levels hampers proper healthcare management. The purpose of the present study was to investigate the early after-effects of lovastatin on the slow-twitch soleus (Sol) and fast-twitch extensor digitorum longus (EDL) muscles.MethodsAdult C57BL/6 mice were orally administrated with placebo or lovastatin [50 mg/kg/d] for 28 days. At the end of the treatment, the isometric ex vivo contractile properties of the Sol and EDL muscles were measured. Subtetanic and tetanic contractions were assessed and contraction kinetics were recorded. The muscles were then frozen for immunohistochemical analyses. Data were analyzed by two-way ANOVA followed by an a posteriori Tukey’s test.ResultsThe short-term lovastatin treatment did not induce muscle mass loss, muscle fiber atrophy, or creatine kinase (CK) release. It had no functional impact on slow-twitch Sol muscles. However, subtetanic stimulations at 10 Hz provoked greater force production in fast-twitch EDL muscles. The treatment also decreased the maximal rate of force development (dP/dT) of twitch contractions and prolonged the half relaxation time (1/2RT) of tetanic contractions of EDL muscles.ConclusionsAn early short-term statin treatment induced subtle but significant changes in some parameters of the contractile profile of EDL muscles, providing new insights into the selective initiation of statin-induced myopathy in fast-twitch muscles.

show abstract

“…Ex vivo contractility studies were performed on isolated EDLs, as previously reported 71 , 72 . Muscles were stimulated with a supra-maximal 1-ms electrical pulse and the resulting twitch recorded.…”

Section: Methodsmentioning

confidence: 99%

Aged skeletal muscle retains the ability to fully regenerate functional architecture

et al. 2013

Self Cite

View full text Add to dashboard Cite

While the general understanding of muscle regenerative capacity is that it declines with increasing age due to impairments in the number of muscle progenitor cells and interaction with their niche, studies vary in their model of choice, indices of myogenic repair, muscle of interest and duration of studies. We focused on the net outcome of regeneration, functional architecture, compared across three models of acute muscle injury to test the hypothesis that satellite cells maintain their capacity for effective myogenic regeneration with age. Muscle regeneration in extensor digitorum longus muscle (EDL) of young (3 mo-old), old (22 mo-old) and senescent female mice (28 mo-old) was evaluated for architectural features, fiber number and central nucleation, weight, collagen and fat deposition. The 3 injury paradigms were: a myotoxin (notexin) which leaves the blood vessels and nerves intact, freezing (FI) that damages local muscle, nerve and blood vessels and denervation-devascularization (DD) which dissociates the nerves and blood vessels from the whole muscle. Histological analyses revealed successful architectural regeneration following notexin injury with negligible fibrosis and fully restored function, regardless of age. In comparison, the regenerative response to injuries that damaged the neurovascular supply (FI and DD) was less effective, but similar across the ages. The focus on net regenerative outcome demonstrated that old and senescent muscle has a robust capacity to regenerate functional architecture.

show abstract

Age- and Gender-Related Changes in Contractile Properties of Non-Atrophied EDL Muscle

Cited by 56 publications

References 54 publications

Plantaris muscle weakness in old mice: relative contributions of changes in specific force, muscle mass, myofiber cross-sectional area, and number

Plantaris muscle weakness in old mice: relative contributions of changes in specific force, muscle mass, myofiber cross-sectional area, and number

A short-term statin treatment changes the contractile properties of fast-twitch skeletal muscles

Aged skeletal muscle retains the ability to fully regenerate functional architecture

Contact Info

Product

Resources

About