Skeletal muscle proteolysis after fatigue and exercise-induced injury Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/7s75df83r

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • Skeletal muscle damage induced by lengthening ("eccentric" or "pliometric") contractions cause an immediate loss in maximal tetanic force (P₀) and an increase in protein degradation by unidentified endogenous mechanisms. We hypothesized that increased proteolysis following active lengthening injury is mediated by the Ca²⁺ dependent protease calpain. To test this hypothesis we constructed an apparatus capable of inducing lengthening-contraction injury in rat extensor digitorum longus (EDL) and measured the calpain-specific proteolysis of a-fodrin in muscles subjected to either 90 in-situ active lengthening contractions (17.4 + 0.3% of fiber length), 90 active isometric contractions, 90 passive lengthening contractions (18.4 ± 0.1% of fiber length) or no contractile treatment. Sixty minutes after the exercise treatments, isometric force had declined 4 ± 2% of P₀ in the isometric-contraction-treated muscles (n = 6), 4 ± 1% in the passivelengthening treatment (n = 3), and 5 ±3% in muscles that received no treatment other than isometric test contractures (n = 3). In contrast, force declined 53 ± 3% of P₀ (P <0.01 vs. all other treatments) in muscles subjected to active lengthening contractions (n = 6). Calpain-mediated fodrinolysis produces 145 kDa and 150 kDa peptides that retain immunoreactivity to the intact ct-fodrin antibody. Densitometric analysis of a-fodrin Western blots showed that levels of these peptides were not different between the active isometric, passive lengthening, no treatment or contralateral muscle groups. In contrast, levels of the 145 kDa and 150 kDa peptides in muscles subjected to lengthening contractions were 5.75-fold greater (P <0.01) than the combined mean of the non-injury treatments and 8.5-fold greater than contralateral muscles (P <0.01). These data indicate that calpain-mediated proteolysis is increased following in situ lengthening contraction-induced injury in rat EDL muscles.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 256 Grayscale) using Capture Perfect 3.0.82 on a Canon DR-9080C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces
Additional Information
  • description.provenance : Made available in DSpace on 2011-08-09T22:35:44Z (GMT). No. of bitstreams: 1MarleyKevin2005.pdf: 4365682 bytes, checksum: 92f0013fec9777e905d263f583fd55ee (MD5) Previous issue date: 2004-06-08
  • description.provenance : Approved for entry into archive by Anna Opoien(anna.opoien@oregonstate.edu) on 2011-08-09T22:35:44Z (GMT) No. of bitstreams: 1MarleyKevin2005.pdf: 4365682 bytes, checksum: 92f0013fec9777e905d263f583fd55ee (MD5)
  • description.provenance : Approved for entry into archive by Anna Opoien(anna.opoien@oregonstate.edu) on 2011-08-09T22:13:24Z (GMT) No. of bitstreams: 1MarleyKevin2005.pdf: 4365682 bytes, checksum: 92f0013fec9777e905d263f583fd55ee (MD5)
  • description.provenance : Submitted by Eric Vanderwall (ewscanner@gmail.com) on 2011-08-09T19:30:14ZNo. of bitstreams: 1MarleyKevin2005.pdf: 4365682 bytes, checksum: 92f0013fec9777e905d263f583fd55ee (MD5)

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items