Molecular and Cellular Biochemistry

, Volume 179, Issue 1, pp 135–145

Exercise-induced muscle injury: A calpain hypothesis

  • Angelo N. Belcastro
  • Leann D. Shewchuk
  • Daniel A. Raj
Article

DOI: 10.1023/A:1006816123601

Cite this article as:
Belcastro, A.N., Shewchuk, L.D. & Raj, D.A. Mol Cell Biochem (1998) 179: 135. doi:10.1023/A:1006816123601

Abstract

It is well established that periods of increased contractile activity result in significant changes in muscle structure and function. Such morphological changes as sarcomeric Z-line disruption and sarcoplasmic reticulum vacuolization are characteristic of exercise-induced muscle injury. While the precise mechanism(s) underlying the perturbations to muscle following exercise remains to be elucidated, it is clear that disturbances in Ca2+ homeostasis and changes in the rate of protein degradation occur. The resulting elevation in intracellular [Ca2+] activates the non-lysosomal cysteine protease, calpain. Because calpain cleaves a variety of protein substrates including cytoskeletal and myofibrillar proteins, calpain-mediated degradation is thought to contribute to the changes in muscle structure and function that occur immediately following exercise. In addition, calpain activation may trigger the adaptation response to muscle injury. The purpose of this paper is to: (i) review the chemistry of the calpain-calpastatin system; (ii) provide evidence for the involvement of the non-lysosomal, calcium-activated neutral protease (calpain) in the response of skeletal muscle protein breakdown to exercise (calpain hypothesis); and (iii) describe the possible involvement of calpain in the inflammatory and regeneration response to exercise.

calcium non-lysosomal proteases muscle damage neutrophils muscle regeneration 

Copyright information

© Kluwer Academic Publishers 1998

Authors and Affiliations

  • Angelo N. Belcastro
    • 1
  • Leann D. Shewchuk
    • 1
  • Daniel A. Raj
    • 1
  1. 1.School of Rehabilitation Sciences, Faculty of MedicineUniversity of British ColumbiaVancouverCanada