Effect of tacrolimus on expression of hepatocyte growth factor in rat spinal cord following peripheral nerve injury.

[Objective]To explore the effect of tacrolimus on expression of hepatocyte growth factor(HGF)in rat spinal cord following peripheral nerve injury.[Method]Fifty male rats were randomly divided into normal group,injury group and treatment group.Models of peripheral nerve injury were established by transection of bilateral sciatic nerve at 0.5 cm distal to piriform muscle.Then treatment group received subcutaneous injection of tacrolimus(1 mg/kg)at the back of the neck,while injury group received 0.9 % saline.The L4~6 spinal cords were harvested at various time points after surgery.Western blotting and immunofluorescence staining were used to detect the level and position of HGF in the spinal cord.[Result]HGF-positive neurons were located in anterior horn,intermediate zone and posterior horn of gray matter in normal spinal cord.There was no significant difference in the expressions of HGF between injury group and normal group,while the expression of HGF was significantly higher in treatment group than that in injury group at 7 and 14 days after surgery.[Conclusion]Peripheral nerve injury does not up-regulate the expression of HGF in spinal cord,while tacrolimus can induce high expression of endogenous HGF after injury to protect neurons and promote axonal outgrowth.