Acute phase response in exercise III. Neutrophil and IL-1β accumulation in skeletal muscle

R. A. Fielding, T. J. Manfredi, W. Ding, M. A. Fiatarone, W. J. Evans, Joseph Gerard Cannon

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368 Scopus citations


Nine untrained men (22-29 yr) performed 45 min of downhill running (16% incline, 70% of maximum heart rate). Needle biopsies of the vastus lateralis were performed before, 45 min after, and 5 days after exercise. Immunohistochemical staining of muscle cross sections revealed a 135% increase in muscle interleukin-1β (IL-1β) immediately after and a 250% increase (P < 0.03) 5 days after exercise. Using a rating scale (0-3) for the presence of neutrophils, light microscopic examination showed a significant accumulation of neutrophils in muscle biopsies taken 45 min after and 5 days after exercise [before: 0.5 ± 0.2, 45 min after: 1.5 ± 0.3 (P < 0.01), and 5 days after: 1.2 ± 0.2 (P < 0.04)]. In addition, electron microscopic analysis showed an increase in the percentage of damaged Z-bands relative to total Z-bands [before: 4.8 ± 3.5%, 45 min after: 32.5 ± 8.6% (P < 0.05), and 5 days after: 14.1 ± 3.2%]. Neutrophil accumulation was positively correlated to intracellular Z-band damage (ρ = 0.66, P < 0.001). Immunohistochemical staining for IL-1β was related to neutrophil accumulation in muscle (ρ = 0.38, P < 0.06) and to plasma creatine kinase levels (ρ = 0.416, P < 0.04). These data indicate that after eccentric exercise ultrastructural damage to skeletal muscle is associated with neutrophil infiltration and muscle IL-1β accumulation.

Original languageEnglish (US)
Pages (from-to)R166-R172
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Issue number1 34-1
StatePublished - 1993


  • Z-band damage
  • interleukin-1β
  • microscopy
  • neutrophil

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)


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