Myosin immunohistochemistry and fiber adaptation following stretch-shortening contraction loading: influence of glutathione and age

Details

• Personal Author:
  Baker BA ; Cutlip, Robert G. ; Hollander MS ; Kashon ML
• Description:
  The extent and contribution of myosin heavy chain plasticity in the adaptive response following glutathione modulation and repetitive mechanical loading is not known. PURPOSE: The purpose of this research was to identify the influence dietary supplementation with a glutathione antagonist (L-Buthionine Sulfoximine (BSO)) has on the adaptability of skeletal muscle during chronic high-intensity mechanical loading via stretch-shortening contractions (SSCs) in young and old rats. METHODS: Left dorsiflexor muscles of young (12 weeks, N= 22) and old (30 months, N = 22), vehicle- (VEH) and BSO-treated rats were exposed 3 times per week for 4.5-weeks to a protocol of 80 maximal SSCs per exposure in vivo, while cage, age-matched rats served as controls (CON). Myofiber plasticity was characterized by myosin heavy chain (MHCslow+, MHCfast+, or MHCdev+) response by immunohistochemical analysis, as well as by changes in muscle cross-sectional area distribution following the exposure period. RESULTS: MHCslow+ content was increased in the old rats, irrespective of treatment or exposure. Conversely, MHCfast+ content was increased in the young rats, regardless of treatment of exposure. MHCdev+ content was not changed following chronic SSC loading. Shifts to larger fiber cross-sectional areas were apparent for all SSC-exposed groups. CONCLUSIONS: MHCdev+ is not expressed following chronic SSC exposure, regardless of age, treatment, or exposure. Aging skeletal muscle does retain some capacity for adaptation; however aging apparently diminishes the adaptive response following chronic SSC exposure. Evidently, a population of small myofibers does exist that do not undergo regeneration in aged skeletal muscle, perhaps accounting for the disparity observed between morphological adaptation and functional performance. [Description provided by NIOSH]
• Subjects:
  Aging Animals Laboratories Musculoskeletal System Occupational Health Safety
• Keywords:
  Age-groups Exposure-levels Laboratory-animals Muscle-function Muscles Musculoskeletal-system Physiological-effects Physiology
• ISSN:
  0195-9131
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  42
• Issue:
  5
• NIOSHTIC Number:
  nn:20044026
• Citation:
  Med Sci Sports Exerc 2009 May; 41(5)(Suppl 1):131
• Email:
  bwb3@cdc.gov
• CAS Registry Number:
  Glutathione (CAS RN 70-18-8)
• Federal Fiscal Year:
  2009
• Peer Reviewed:
  False
• Source Full Name:
  Medicine and Science in Sports and Exercise
• Supplement:
  1
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9087f54327222060d7c4419bba30495b86bf81a051d468831895092c49a7872096bcf30461265d97b55ca6b243573e8491822d75ebbb3f6022d23e3dbd711549
• Download URL:
  https://stacks.cdc.gov/view/cdc/199880/cdc_199880_DS1.pdf
• File Type:
  [PDF - 44.38 KB ]