Skeletal Muscle Fiber Types and Myosin ATPase Activity Do Not Change With Age or Growth Hormone Administration

Florini, James R.; Ewton, Daina Z.; Roof, L.; Ostuni, Joseph J.

doi:10.1093/geronj/44.5.b110

Cited by 49 publications

(27 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There was no age-related difference in myosin ATPase activity of soleus, EDL, or diaphragm muscles (Florini and Ewton, 1989) or among "white" or "red" hindlimb muscles (Honorati and Ermini, 1974). Syrovy and Gutmann, on the other hand, reported data showing an age-related trend for low myofibrillar Ca 2+ -activated ATPase and purified myosin ATPase activities in soleus and EDL muscles (Syrovy and Gutmann, 1970).…”

Section: Discussionmentioning

confidence: 87%

Myofibrillar myosin ATPase activity in hindlimb muscles from young and aged rats

Lowe

Husom

Ferrington

et al. 2004

Mechanisms of Ageing and Development

View full text Add to dashboard Cite

We tested the hypothesis that Ca 2+ -activated myosin ATPase activity is lower in muscles of aged rats relative to muscles of young rats, independent of changes in myosin isoform expression. Myofibrils were prepared from permeabilized fibers of soleus, plantaris, and semimembranosus muscles of young (8-12 months) and aged (32-38 months) F344 × BN rats and assayed for resting myosin ATPase, Ca 2+ -activated myosin ATPase, and myosin heavy chain (MHC) and myosin light chain (MLC) isoform compositions. Resting myosin ATPases were not affected by age in any muscle (P ≥ 0.42). Ca 2+ -activated myosin ATPases of soleus and plantaris myofibrils were not affected by age (P ≥ 0.31) but were 16% lower in semimembranosus myofibrils from aged rats (0.448 ± 0.019 μmol P i /min/mg) compared to young rats (0.533 ± 0.031 μmol P i /min/mg; P = 0.03). Correspondingly, maximal unloaded shortening velocity of single semimembranosus fibers from aged rats was slow (4.6 ± 0.2 fiber lengths/s) compared with fibers from young rats (5.8 ± 0.3 fiber lengths/s; P < 0.01). No age-related changes in MHC or regulatory MLC isoforms were detected in any muscle (P ≥ 0.08) but changes in the essential MLC occurred in plantaris and semimembranosus muscles. The data indicate that Ca 2+ -activated myosin ATPase activity is reduced with age in semimembranosus muscle, independent of age-related changes in MHC isoform expression, and is one mechanism contributing to age-related slowing of contraction in that muscle.

show abstract

Section: Discussionmentioning

confidence: 87%

Myofibrillar myosin ATPase activity in hindlimb muscles from young and aged rats

Lowe

Husom

Ferrington

et al. 2004

Mechanisms of Ageing and Development

View full text Add to dashboard Cite

show abstract

“…Most studies did not account for the effects of other pituitary hormone deficiencies on muscle fibre types, in particular thyroid hormone. When investigating the effects of GH in normal rats, Florini & Ewton (1989) observed no significant change in the number of type I or type II fibres after 6 months. These results in normal rats have been confirmed by other groups (Ullman & Oldfors 1989, Bigard et al 1994, Aroniadou-Anderjaska et al 1996.…”

Section: Gh Regulation Of Functional Muscle Proteins and Muscle Fibrementioning

confidence: 89%

Action of GH on skeletal muscle function: molecular and metabolic mechanisms

Chikani

2013

Journal of Molecular Endocrinology

View full text Add to dashboard Cite

Skeletal muscle is a target tissue of GH. Based on its anabolic properties, it is widely accepted that GH enhances muscle performance in sports and muscle function in the elderly. This paper critically reviews information on the effects of GH on muscle function covering structure, protein metabolism, the role of IGF1 mediation, bioenergetics and performance drawn from molecular, cellular and physiological studies on animals and humans. GH increases muscle strength by enhancing muscle mass without affecting contractile force or fibre composition type. GH stimulates whole-body protein accretion with protein synthesis occurring in muscular and extra-muscular sites. The energy required to power muscle function is derived from a continuum of anaerobic and aerobic sources. Molecular and functional studies provide evidence that GH stimulates the anaerobic and suppresses the aerobic energy system, in turn affecting power-based functional measures in a time-dependent manner. GH exerts complex multi-system effects on skeletal muscle function in part mediated by the IGF system.

show abstract

“…Previous studies [46,47] have shown that the muscle contraction time and muscle relaxation time lengthen with age and any changes to these phases of muscle contraction influence the efficiency of the older adult to perform activities. Since muscle strength and the ability of the leg muscles to develop force rapidly are important performance characteristics contributing to several tasks of daily life, or even prevention of falls and trips [40,48], this should be taken into consideration when constructing strength training programmes for both middle-aged and older men and women.…”

Section: Discussionmentioning

confidence: 99%

Age-related changes in upper body strength and lower limb power of professional Italian firefighters

Perroni

Guidetti

Cignitti³

et al. 2015

Sport Sci Health

View full text Add to dashboard Cite

Purpose Considering that the decrease in strength can be observed with ageing and that muscular endurance and strength are essential factors for firefighting effectiveness in critical situations, the purpose of this study was to evaluate the Upper Body Strength and Lower Limb Power of Professional of Italian Firefighters of 229 Italian male firefighters (age 32 ± 8 years, height 177 ± 6 cm, weight 79 ± 9 kg, BMI 24.5 ± 2.4 kg/m 2 ) and to compare the results in relation to the age (\30-year-old group; 31-to 35-year-old group; 36-to 40-year-old group; 41-to 45-year-old group; [45-year-old group). Methods Upper body strength (1RM bench press), lower limb power (counter movement jump-CMJ, and sprint ability-20 m) were analysed. Descriptive statistics and an Analysis of Variance (ANOVA) were applied to anthropometric and physical fitness values to assess significant difference between age groups. When a significant effect was found, Bonferroni's post hoc analysis was used. Results Between age groups, anthropometric values showed an age effect (p \ 0.05) for BMI with 34 % of all firefighters in overweight and high prevalence (52 %) in [45 compared to the other age group categories. Performances values showed differences for 1RM bench press [F (4,223) = 6.17; p \ 0.001], CMJ [F (4,223) Conclusions Considering that the ability to produce strength and power movements are very important qualities to firefighters in each age, individuals and ''job specific'' training programs should be planned with functional work activities to improve neuromuscular function at any age.

show abstract

Skeletal Muscle Fiber Types and Myosin ATPase Activity Do Not Change With Age or Growth Hormone Administration

Cited by 49 publications

References 22 publications

Myofibrillar myosin ATPase activity in hindlimb muscles from young and aged rats

Myofibrillar myosin ATPase activity in hindlimb muscles from young and aged rats

Action of GH on skeletal muscle function: molecular and metabolic mechanisms

Age-related changes in upper body strength and lower limb power of professional Italian firefighters

Contact Info

Product

Resources

About