Reduced Frequency of Resistance-Type Exercise Training Promotes Adaptation of the Aged Skeletal Muscle Microenvironment

Details

• Personal Author:
  Baker BA ; Ensey J ; Kashon ML ; Naimo MA ; Rader EP
• Description:
  The purpose of this study was to characterize the growth and remodeling molecular signaling response in aged skeletal muscle following one month of "resistance-type exercise" training. Male Fisher344x Brown Norway hybrid rats aged 3 (young) and 30 months (old) underwent stretch-shortening contraction (SSC) loading two or three days per week; muscles were removed 72 hours post-training. Young rats SSC-loaded three (Y3x) or two days per week (Y2x) adapted via increased work performance. Old rats SSC-loaded three days per week (O3x) maladapted via decreased negative work; however, old rats SSC-loaded two days per week (O2x) adapted through improved negative and positive work. Y3x, Y2x, and O2x, but not O3x, displayed hypertrophy via larger fiber area and myonuclear domains. Y3x, Y2x, and O2x differentially expressed 19, 30, and 8 PI3K-AKT genes, respectively, whereas O3x only expressed two. Bioinformatics analysis revealed that rats in the adapting groups presented growth and remodeling processes (i.e. increased protein synthesis), whereas O3x demonstrated inflammatory signaling. In conclusion, reducing SSC-loading frequency in aged rodents positively influences the molecular signaling microenvironment, promoting muscle adaptation. [Description provided by NIOSH]
• Subjects:
  Aging Laboratories Musculoskeletal System Occupational Health Particulate Matter Safety
• Keywords:
  Adaptation Author Keywords: Stretch-shortening Contractions Bioinformatics Central Nuclei Fibers Fisher 344 X Brown Norway Rats Growth And Remodeling Laboratory Animals Molecular Biology Muscles Musculoskeletal System Physical Exercise Proteins

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• ISSN:
  8750-7587
• Document Type:
  Text
• Genre:
  Journal Article
• 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:
  126
• Issue:
  4
• NIOSHTIC Number:
  nn:20054550
• Citation:
  J Appl Physiol 2019 Apr; 126(4):1074-1087
• Contact Point Address:
  Brent A. Baker, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Health Effects Laboratory Division, 1095 Willowdale Road, MS-L3027, Morgantown, WV 26505-2888
• Email:
  bwb3@cdc.gov
• Federal Fiscal Year:
  2019
• Peer Reviewed:
  True
• Source Full Name:
  Journal of Applied Physiology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:cd6e535014dcc03ea45125799017aaab83012691bc24d698e5fbc2ac48c0aad04b9ddf4c9c1c25462421701aa3319f3c0a1244e49ce35684095d059d7e047e59
• Download URL:
  https://stacks.cdc.gov/view/cdc/217078/cdc_217078_DS1.pdf
• File Type:
  [PDF - 560.00 KB ]