The expression of GDNF in injured sciatic nerve of rats

Objective To investigate the expression of Glial cell line-derived neurotrophic factor (GDNF) in normal and injured sciatic nerves of rats. Methods Sixty adult SD rats were divided into three groups according to injury type transection group, crush group and normal control group. The specimen of normal sciatic nerve and injured sciatic nerve proximal and distal to the transection or crush site were taken at 1,2,4,6,8 weeks after injury. The immunohistochemical staining was performed on slides of all three groups. Results Low level expression of GDNF was detected on normal sciatic nerve. Expression of GDNF was upgraded on injured sciatic nerve. In transection group the expression of GDNF reached the peak at the 2nd week in distal segment and at the 4th week at the proximal segment. In crush group expression of GDNF was basically same in the proximal and distal segment, increased gradually and reached the peak at the 8th week. Conclusion Expression of GDNF is upgraded in injured sciatic nerve in various way according to the type of injury and time course.