Functional deficits and insulin-like growth factor-I gene expression following tourniquet-induced injury of skeletal muscle in young and old rats

David W. Hammers, Edward K. Merritt, Wayne Matheny, Martin L. Adamo, Thomas J. Walters, J. Scot Estep, Roger P. Farrar

Research output: Contribution to journalArticle

23 Scopus citations


This study investigated the effect of age on recovery of skeletal muscle from an ischemia-reperfusion (I/R)-induced injury. Young (6 mo old) and old (24-27 mo old) Sprague-Dawley rats underwent a 2-h bout of hindlimb ischemia induced by a pneumatic tourniquet (TK). The TK was released to allow reperfusion of the affected limb, and animals were divided into 7- and 14-day recovery groups. Maximum plantar flexor force production was assessed in both 7- and 14-day recovery groups of both ages, followed by histological evaluation. Subsequent analysis of IGF-I gene expression and intracellular signaling in 7-day recovery muscles was performed by RT-PCR and Western blotting, respectively. Old rats had significantly greater deficits in force production and exhibited more evidence of histological pathology than young at both 7 and 14 days postinjury. In addition, old rats demonstrated an attenuated upregulation of IGF-I mRNA and induction of proanabolic signaling compared with young in response to injury. We conclude that aged skeletal muscle exhibits more damage and/or defective regeneration following I/R and identify an age-associated decrease in local IGF-I responsiveness as a potential mechanism for this phenomenon.

Original languageEnglish (US)
Pages (from-to)1274-1281
Number of pages8
JournalJournal of applied physiology
Issue number4
StatePublished - Oct 2008



  • Aging
  • Insulin-like growth factor-I
  • Ischemia-reperfusion
  • Muscle regeneration
  • Sarcopenia

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this