嗅鞘细胞移植和L-NNA对大鼠脊髓损伤后背核神经元存活及其轴突再生的影响

Objective To investigate the effects of transplanted olfactory ensheathing cells (OECs)and L-NNA on neuronal survival and axonal regeneration in Clarke’s Nucleus (CN) after spinal cord hemisection of rats.Methods 20 rats were divided into control group, L-NNA group, OECs group, OECs+L-NNA group after spinal cord hemisection. OECs were transplanted into the injured site of spinal cord and L-NNA was injected in OECs+L-NNA group of rats. 30days after operation, NADPH enzyme histochemistry, immunohistochemistry, neutral red staining, HE staining and fluorogold retrogradatic labeling were applied to determine the survival and axonal regeneration of neurons at L1 CN in 4 groups of rats.Results: ①The number of neuronal survival at L1 CN in OECs group and L-NNA group was higher than that in control group. The effect of promoting the survival of big, middle and small neurons at CN of spinal cord in OECs group and L-NNA group was showed by differential count. The effect of promoting neuronal survival was most significant in OECs+L-NNA group. ②The regenerating axons were observed at the injured site of spinal cord and the neuron’s bodies labeled by fluorogold retrogradation were found at L1 CN in OECs group and OECs+L-NNA group.③Compared with control group, Nitric oxide synthase (NOS) positive neurons were increased in OECs group, decreased in L-NNA group, and were no difference in OECs+L-NNA group.Conclusion Transplanted OECs or L-NNA may facilitate the survival of injured CN neurons of spinal cord. Combination of transplanted OECs and L-NNA can preferably promote the survival and axonal regeneration of injured CN neurons.