Insulin-like growth factor immunoreactivity increases in muscle after acute eccentric contractions

J Appl Physiol (1985). 1993 Jan;74(1):410-4. doi: 10.1152/jappl.1993.74.1.410.


The purpose of the study was to note whether insulin-like growth factor (IGF) immunoreactivity increased after eccentric contractions. IGF immunoreactivity in the rat tibialis anterior muscle was measured on 5 successive days (4-5 rats/group, n = 28) after an acute bout of 192 eccentric contractions elicited by electrical stimulation. The muscle tissue sections were immunocytochemically processed with rabbit anti-human IGF-I serum. Immunoreactivity was analyzed with videomicroscopy and computer-aided image processing. Four days after eccentric contractions, IGF immunoreactivity was significantly higher than control [0.081 +/- 0.073 (SD) absorbance at 480 nm vs. 0.026 +/- 0.018; P < 0.05]. The increases in IGF-I immunoreactivity were mostly within the muscle fibers. These results suggest that an acute bout of eccentric exercise increases IGF-I immunoreactivity in rat type II muscle 4 days postexercise.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Female
  • Image Processing, Computer-Assisted
  • Immunohistochemistry
  • Insulin-Like Growth Factor I / immunology
  • Insulin-Like Growth Factor I / metabolism*
  • Muscle Contraction / physiology
  • Muscle Proteins / biosynthesis
  • Muscles / anatomy & histology
  • Muscles / metabolism*
  • Physical Exertion / physiology*
  • Rats
  • Rats, Sprague-Dawley


  • Muscle Proteins
  • Insulin-Like Growth Factor I