Insulin-like growth factor I promotes nerve regeneration: an experimental study on rat sciatic nerve.
Insulin-like growth factor I (IGF-I; somatomedin C) has previously been demonstrated, with immunohistochemical methods, to accumulate locally at the site of trauma of an injured peripheral nerve. In the experiments reported here a Y-shaped silicone-chamber system was used to test if local infusion of IGF-I had supportive effects on nerve regeneration. The proximal end of a cut sciatic nerve was inserted into one channel of the Y-shaped chamber and the length and growth direction of the regenerating myelinated axons were evaluated after 1 month. When IGF-I (250 micrograms/ml 0.5 microliters/h) was infused into one channel by an osmotic pump, the length of the regenerating axons increased significantly compared to the control groups with no IGF-I added. In some instances the regenerating axons grew towards the osmotic pump. It is concluded that local infusion of IGF-I at appropriate concentration promotes regeneration of a peripheral nerve. It exerts a neuronotrophic but not a clear chemotactic effect.
Nachemson
A K
AK
Department of Orthopaedics, Gothenburg University, Sweden.
Lundborg
G
G
Hansson
H A
HA
D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000187:drug effects / Q000502:physiology; D009416:Nerve Regeneration / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012584:Sciatic Nerve / Q000187:drug effects / Q000502:physiology*
D007334:Insulin-Like Growth Factor I