Effect of FK506 administration in alpha motor neurons after primary and delayed repair of the sciatic nerve

Objectives: FK506 is an effective immunosuppressive drug for treating graft rejection in transplants patients. However, the neuroregenerative effect of FK506 has been well described in the literature. The aim of this study was to investigate the effects of FK506 in alpha motor neurons after primary and delayed repair of sciatic nerve.Methods: Rats (n=72) were divided into 6 groups. Control, sham-operated, primary repair FK506 (-), primary repair FK506 (+), delayed repair FK506 (-), and delayed repair FK506 (+) groups.Results: After injury, the normal structure of the motor neuron perikarya was maintained by primary repair in the FK506 (+) group. In the delayed repair group, beneficial effect of FK506 was found to be less effective. The SFI value reached -50 recovery level in the FK506-treated group earlier than those of not FK506-treated groups.Conclusion: Beneficial effect of FK506 has been approved by functional and ultrastructural data in both of primary and delayed repair groups.