Aging enhances serum cytokine response but not task-induced grip strength declines in a rat model of work-related musculoskeletal disorders

Details

• Alternative Title:
  BMC Musculoskelet Disord
• Personal Author:
  Xin, Dong L ; Harris, Michelle Y ; Wade, Christine K ; Amin, Mamta ; Barr, Ann E ; Barbe, Mary F
• Description:
  Background
  
  We previously reported early tissue injury, increased serum and tissue inflammatory cytokines and decreased grip in young rats performing a moderate demand repetitive task. The tissue cytokine response was transient, the serum response and decreased grip were still evident by 8 weeks. Thus, here, we examined their levels at 12 weeks in young rats. Since aging is known to enhance serum cytokine levels, we also examined aged rats.
  
  Methods
  
  Aged and young rats, 14 mo and 2.5 mo of age at onset, respectfully, were trained 15 min/day for 4 weeks, and then performed a high repetition, low force (HRLF) reaching and grasping task for 2 hours/day, for 12 weeks. Serum was assayed for 6 cytokines: IL-1alpha, IL-6, IFN-gamma, TNF-alpha, MIP2, IL-10. Grip strength was assayed, since we have previously shown an inverse correlation between grip strength and serum inflammatory cytokines. Results were compared to naïve (grip), and normal, food-restricted and trained-only controls.
  
  Results
  
  Serum cytokines were higher overall in aged than young rats, with increases in IL-1alpha, IFN-gamma and IL-6 in aged Trained and 12-week HRLF rats, compared to young Trained and HRLF rats (p < 0.05 and p < 0.001, respectively, each). IL-6 was also increased in aged 12-week HRLF versus aged normal controls (p < 0.05). Serum IFN-gamma and MIP2 levels were also increased in young 6-week HRLF rats, but no cytokines were above baseline levels in young 12-week HRLF rats. Grip strength declined in both young and aged 12-week HRLF rats, compared to naïve and normal controls (p < 0.05 each), but these declines correlated only with IL-6 levels in aged rats (r = -0.39).
  
  Conclusion
  
  Aging enhanced a serum cytokine response in general, a response that was even greater with repetitive task performance. Grip strength was adversely affected by task performance in both age groups, but was apparently influenced by factors other than serum cytokine levels in young rats.
  
  
• Subjects:
  Aging Animals Cumulative Trauma Disorders Disease Models, Animal Female Hand Strength Interleukin-6 Muscle Strength Musculoskeletal Diseases Rats Rats, Sprague-Dawley Time Factors

  More +
• Source:
  BMC Musculoskelet Disord. 2011; 12:63.
• Pubmed ID:
  21447183
• Pubmed Central ID:
  PMC3072947
• Document Type:
  Journal Article
• Funding:
  OH 03970/OH/NIOSH CDC HHS/United States ; OH-05-004/OH/NIOSH CDC HHS/United States ; R01 AR056019/AR/NIAMS NIH HHS/United States ; R01 AR056019-03/AR/NIAMS NIH HHS/United States
• Volume:
  12
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:f6541df4a4992617bac57c1c2f3be5a77a44a9ce1b0e0b20f2c4f720692f513a
• Download URL:
  https://stacks.cdc.gov/view/cdc/22820/cdc_22820_DS1.pdf
• File Type:
  [PDF - 1.11 MB ]