Accession Number:

ADA627696

Title:

Functional Deficits and Insulin-Like Growth Factor-I Gene Expression Following Tourniquet-Induced Injury of Skeletal Muscle in Young and Old Rats

Descriptive Note:

Journal article

Corporate Author:

ARMY INST OF SURGICAL RESEARCH FORT SAM HOUSTON TX

Report Date:

2008-07-31

Pagination or Media Count:

9.0

Abstract:

This study investigated the effect of age on recovery of skeletal muscle from an ischemia-reperfusion IR-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 andor defective regeneration following IR and identify an age-associated decrease in local IGF-I responsiveness as a potential mechanism for this phenomenon.

Subject Categories:

  • Genetic Engineering and Molecular Biology
  • Anatomy and Physiology
  • Medicine and Medical Research
  • Medical Facilities, Equipment and Supplies

Distribution Statement:

APPROVED FOR PUBLIC RELEASE