dc.contributor.author | Raastad, Truls | |
dc.contributor.author | Owe, Simen Gylterud | |
dc.contributor.author | Paulsen, Gøran | |
dc.contributor.author | Enns, Deborah | |
dc.contributor.author | Overgaard, Kristian | |
dc.contributor.author | Crameri, Regina | |
dc.contributor.author | Kiil, Steinar | |
dc.contributor.author | Belcastro, Angelo | |
dc.contributor.author | Bergersen, Linda Hildegard | |
dc.contributor.author | Hallén, Jostein | |
dc.date.accessioned | 2011-01-12T13:52:47Z | |
dc.date.available | 2011-01-12T13:52:47Z | |
dc.date.issued | 2010-01 | |
dc.identifier | Seksjon for fysisk prestasjonsevne / Department of Physical Performance | |
dc.identifier.citation | Medicine & Science in Sports & Exercise. 2010, 42(1), 86-95 | en_US |
dc.identifier.issn | 0195-9131 | |
dc.identifier.uri | http://hdl.handle.net/11250/170663 | |
dc.description | I Brage finner du siste tekst-versjon av artikkelen, og den kan inneholde ubetydelige forskjeller fra forlagets pdf-versjon. Forlagets pdf-versjon finner du på www.ovid.com: http://dx.doi.org/10.1249/MSS.0b013e3181ac7afa
/ In Brage you'll find the final text version of the article, and it may contain insignificant differences from the journal's pdf version. The original publication is available at www.ovid.com: http://dx.doi.org/10.1249/MSS.0b013e3181ac7afa | en_US |
dc.description.abstract | 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. | en_US |
dc.language.iso | eng | en_US |
dc.publisher | LWW | en_US |
dc.subject | analysis of variance | |
dc.subject | biopsy | |
dc.subject | calpain | |
dc.subject | exercise | |
dc.subject | immunohistochemistry | |
dc.subject | leg | |
dc.subject | muscle contraction | |
dc.subject | muscle fatigue | |
dc.subject | muscle, skeletal | |
dc.subject | myofibrils | |
dc.subject | torque | |
dc.title | Changes in calpain activity, muscle structure, and function after eccentric exercise | en_US |
dc.type | Journal article | en_US |
dc.type | Peer reviewed | en_US |
dc.subject.nsi | VDP::Social science: 200::Social science in sports: 330::Other subjects within physical education: 339 | en_US |
dc.source.pagenumber | 86-95 | en_US |