Objective    To investigate the role of insulin-like grow factor 1 (IGF-1) on the regeneration of peripheral nerve after operation.      Methods    The right sciatic nerve of adult female SD rats was transected and bridged with silicone tube. IGF-1 was injected into the silicone tube in the treated group

while normal saline instead in control group

with 30 rats in each group. On postoperative day 3

5

7

9 and 11

the regeneration of axons was observed by SABC immunohistochemical methods with anti-neurofilment 200

and the proliferation of Schwann cells was measured with anti-S-100.     Results    Significant difference was seen in the length of regenerating neurites and the number of Schwann cells at all time points between two groups (P0.01).     Conclusion    Local application of IGF-1 in the regenerative chamber after transaction promotes the proliferation of Schwann cells and the growth of neurites.