Expression of Schwann cell derived n euro trophic factor after injuried of sciatic nerve of rats / 中华显微外科杂志

ABSTRACT

Objective To investig ate the expression of Schwann cell derived fa ctor （SDNF） in normal or under the condi tion of different injuries on the sciati c nerves of rats. Methods Sevent y-five S D rats were divided into three groups ac cording to different injuri es including transection， transection fo llowed by epineurial suture， and crush. Ten normal rats were treated as control. T he immunohistochemistry of both sciatic nerve and spinal cord were performed at 5，7，14，30，60 days after operation respec tively. Result （1）lower levels o f SDNF were detected in normal sciatic nerve， t he whole white matter and the laminae Ⅲ～ Ⅴ of dorsal horn of spinal cord. （2）In g roup transection， the SDNF levels reache d a maxium at 14 days after operation in proxi mal segment， at 7 days in distal segment ， and at 5 days in spinal cord. There ap peared a highest expression in related t issue of both group crushing and group s uturing at 60 days after operation. （3）SD N F staining of dorsal horn ipsilateral to the nerve lesion was stronger than that of contralateral. There was a transient expression in spinal motor neurons ipsi lateral to nerve lesion at 5 days in gro up crushing and group transection and at 30 days in group suturing. Conclusi on （1）There is a weaker expression i n norma l sciatic nerve and spinal cord. （2）The expression of SDNF varies with the diffe rent nerve lesions. （3）Significant quant ities of SDNF are released from Schwann cells after nerve lesion， and SDNF is then available to the axon of the lesioned neurons which may promote neuro n repair.