Increase of insulin-like growth factor (IGF)-1, IGF binding protein-2 and -4 mRNAs following cerebral contusion

Brain Res Mol Brain Res. 1996 Jun;38(2):285-93. doi: 10.1016/0169-328x(95)00346-t.


The insulin-like growth factor (IGF) system has a role in repair following hypoxic-ischemic injury in many tissues including the brain. To study the involvement of the IGF system following head trauma, we used a rat contusion model, which produces a focal lesion of the cerebral cortex. Molecules in the IGF system were analyzed using in situ hybridization at different times following impact. We observed a dramatic up-regulation of insulin-like growth factor binding protein-2 (IGFBP-2) mRNA in cortical areas adjacent to the injury 24 h after impact, with a peak 10-fold increase engaging most of the ipsilateral cortex 2 and 3 days post-contusion. Seven days after the contusion, IGFBP-2 expression was only moderately up-regulated and again concentrated around the injury. IGFBP-4 mRNA levels increased 4-fold ipsilateral to the site of injury, with retained pattern of cortical expression. IGFBP-3, IGFBP-5 and IGFBP-6 mRNA all displayed distinct expression patterns in the brain but no significant changes were observed following injury. In contrast, IGF-1 mRNA levels were very low prior to contusion, but increased markedly at the site of injury with a peak at day 3. We were unable to detect any changes in the type 1 IGF-receptor or IGF-2 mRNA following contusion. The neuropeptide cholecystokinin (CCK) mRNA was clearly up-regulated following contusion, with an even distribution over the ipsilateral cortex. The expression pattern of molecules in the IGF system post-contusion differs in part to changes observed following hypoxic-ischemia or ischemia alone, perhaps reflecting different regulatory mechanisms depending on the type of injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers
  • Brain Concussion / metabolism*
  • Cerebral Cortex / injuries
  • Cholecystokinin / biosynthesis
  • Disease Models, Animal
  • Gene Expression
  • Image Processing, Computer-Assisted
  • In Situ Hybridization
  • Insulin-Like Growth Factor Binding Protein 2 / genetics*
  • Insulin-Like Growth Factor Binding Protein 4 / genetics*
  • Insulin-Like Growth Factor I / metabolism*
  • Male
  • Nerve Tissue Proteins / genetics*
  • RNA, Messenger / metabolism*
  • Rats
  • Rats, Sprague-Dawley


  • Biomarkers
  • Insulin-Like Growth Factor Binding Protein 2
  • Insulin-Like Growth Factor Binding Protein 4
  • Nerve Tissue Proteins
  • RNA, Messenger
  • Insulin-Like Growth Factor I
  • Cholecystokinin