1 Department of Clinical Sciences, Faculty of Veterinary Medicine, Urmia Branch, Islamic Azad University, Urmia, Iran

2 Department of Internal Medicine and Clinical Pathology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.

3 Solid Tumor Research Center, Urmia University of Medical Sciences, Urmia, Iran.


Objective: To assess the neuroprotective effects of local administration of 17- beta- estradiol on nerve regeneration.Methods: Sixty female Wistar rats were overiectomized and divided into four experimental groups (n = 15), randomly: In autograft group a segment of sciatic nerve was transected and re-implanted reversely. In sham-surgery group sciatic nerve was exposed and manipulated. In transected group left sciatic nerve was transected and stumps were fixed in adjacent muscle. In treatment group defect was bridged using a silicon conduit filled with 10 µL (0.1 mg/mL) 17- beta- estradiol. Each group was subdivided into four subgroups of five animals each and nerve fibers were studied in a 12-week period.Results: Behavioral, functional, biomechanical, electrophysiological and gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in treatment group than in other groups (p<0.05). Immunohistochemical reactions to S-100 in treatment group were more positive than that in other groups.Conclusion: Local administration of 17-beta-estradiol improved functional recovery and morphometric indices of sciatic nerve. It could have clinical implications for the surgical management of patients after facial nerve transection.