Abstract: Objective To investigate the possible protective effect of neurotropin on the corresponding spinal cord motoneuron after sciatic nerve injury early in rats.Methods 108 male Sprague Dawley rats were divided randomly into Groups A,B and C with 36 animals in each group,and all animals were cut both side of sciatic nerve,instantly make the operation of end-to-end anastomose of epineurium for abscised sciatic nerve.Group A was control group.Group B was treated with neurotropin and Group C was treated with normal saline after operation.The rats were sacrificed on 1st d,4th d,9th d,14th d,21st d and 28th d after operation.The corresponding spinal cord segments(L₄～L₆)were gotten to make Bcl-2 and Bax immunohistochemical staining and TUNEL staining.Results The values of Bcl-2/Bax on 9th d,14th d and 21st d after operation of Group B were different from that of Group A and Group C.The number of positive cells stained by TUNEL staining on 9th d was significantly different among Group A,Group B and Group C(v<0.05).The expression of positive TUNEL staining cells reached a peak on 14th d after operation,the number of Group B was less than that of Group A and Group C.Conclusion After instantly make the operation of end-to-end anastomose of epineurium for abscised sciatic nerve,neurotropin can protect the spinal cord motoneurons to avoid apoptosis excessively in some extent.

Key words: sciatic nerve injury, neurotropin, neuron protection, neuron apoptosis, Bcl-2, Bax