Document Detail


Changes in calpain activity, muscle structure, and function after eccentric exercise.
MedLine Citation:
PMID:  20010126     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: The aim of this study was to investigate changes in muscle function, muscle structure, and calpain activity after high-force eccentric exercise. METHODS: Eleven healthy males performed 300 maximal voluntary eccentric actions with knee extensors in one leg. Maximal force-generating capacity was measured before exercise and regularly during the next 7 d. Biopsies from musculus vastus lateralis were taken in both control and exercised legs 0.5, 4, 8, 24, 96, and 168 h after exercise for evaluation of myofibrillar structure, extracellular matrix proteins, and calpain activity. RESULTS: In the exercised leg, peak torque was reduced by 47 +/- 5% during exercise and was still 22 +/- 5% lower than baseline 4 d after the exercise. Calpain activity was three times higher in the exercised leg compared with the control leg 30 min after exercise. Myofibrillar disruptions were observed in 36 +/- 6% of all fibers in exercised muscle and in 2 +/- 1% of fibers in control muscle. The individual reductions in peak torque correlated with the proportion of fibers with myofibrillar disruptions (r = 0.89). The increase in calpain activity was not correlated to the proportion of fibers with myofibrillar disruptions. Nevertheless, the characteristics of the myofibrillar disruptions mimicked calpain-mediated degradation of myofibrils. Tenascin-C and the N-terminal propeptide of procollagen type III showed increased staining intensity on cross-sections 4-7 d after the exercise. CONCLUSIONS: Myofibrillar disruptions seem to be a main cause for the long-lasting reduction in force-generating capacity after high-force eccentric exercise. The increase in calpain activity, but the lack of a relationship between calpain activity and the amount of muscle damage, suggests multiple roles of calpain in the damage and repair process.
Authors:
Truls Raastad; Simen Gylterud Owe; G?ran Paulsen; Deborah Enns; Kristian Overgaard; Regina Crameri; Steinar Kiil; Angelo Belcastro; Linda Bergersen; Jostein Hall?n
Related Documents :
11860376 - Responses of human elbow flexor muscles to electrically stimulated forced lengthening e...
12069266 - Exercise does not induce major changes in plasma muscle enzymes, creatinine, glucose an...
18976956 - The effects of multidirectional soccer-specific fatigue on markers of hamstring injury ...
15817716 - Comparison of the symptoms of exercise-induced muscle damage after an initial and repea...
16235016 - Current practice of exercise stress testing among pediatric cardiology and pulmonology ...
23340006 - Breakfast and exercise contingently affect postprandial metabolism and energy balance i...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Medicine and science in sports and exercise     Volume:  42     ISSN:  1530-0315     ISO Abbreviation:  Med Sci Sports Exerc     Publication Date:  2010 Jan 
Date Detail:
Created Date:  2009-12-17     Completed Date:  2010-03-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8005433     Medline TA:  Med Sci Sports Exerc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  86-95     Citation Subset:  IM; S    
Affiliation:
Norwegian School of Sport Sciences, Oslo, Norway. truls.raastad@nih.no
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Analysis of Variance
Biopsy
Calpain / metabolism*
Exercise / physiology*
Humans
Immunohistochemistry
Leg / physiology
Male
Muscle Contraction / physiology
Muscle Fatigue / physiology
Muscle, Skeletal / anatomy & histology*,  physiology*
Myofibrils / physiology
Torque
Chemical
Reg. No./Substance:
EC 3.4.22.-/Calpain

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Cycle training increased GLUT4 and activation of mammalian target of rapamycin in fast twitch muscle...
Next Document:  Time course of leukocyte accumulation in human muscle after eccentric exercise.