Guided Regeneration of Nerve Repair by Means of Local Administration of Insulin-Like Growth Factor I In Streptozotocin Induced Diabetes In Rats

The aim was to evaluate the effect of locally administered insulin-like growth factor (IGF I) on functional recovery of peripheral nerve in diabetic rats. Sixty male healthy white Wistar rats were divided into four experimental groups (n = 15), randomly: In transected group (TC), left sciatic nerve was transected and stumps were fixed in the adjacent muscle. In treatment group defect was bridged using a silicone conduit (SIL/IGF) and filled with 10 µL IGF I (100 ng/kg). In silicone graft group (SIL), the graft was filled with phosphate-buffered saline alone. In sham-operated group (SHAM), sciatic nerve was exposed and manipulated. Each group was subdivided into three subgroups of five animals each and regenerated nerve fibers were studied 4, 8 and 12 weeks after surgery. Behavioral testing, sciatic nerve functional study, gastrocnemius muscle mass and morphometric indices confirmed faster recovery of regenerated axons in SIL/IGF than in SIL group (p < 0.05). In immunohistochemistry, location of reactions to S-100 in SIL/IGF was clearly more positive than that in SIL group. When loaded in a silicone graft, IGF I accelerated and improved functional recovery and morphometric indices of sciatic nerve in diabetic rats.