L-NNA对大鼠急性脊髓损伤的影响

实验采用雌性 Wistar大鼠 41只 ,分为正常对照组、生理盐水对照组和 L - NNA治疗组 ,后两组制成不完全性(2 18克厘米力 )急性脊髓 (第 10胸髓 )损伤模型 ,于术后每天一次腹腔注射 L - NNA (2 0 m g/ kg)或等量生理盐水 ,连续四周 ,然后处死动物 ,行脊髓 NOS染色和超微结构观察。结果显示 ,L - NNA治疗组脊髓 NOS阳性神经元染色较生理盐水对照组浅 ,两组光密度比较 P<0 .0 5 ;超微结构观察 ,生理盐水对照组脊髓神经元胞质呈空泡样变 ,线粒体等细胞器变性 ,髓鞘严重变形 ,少数髓鞘呈线团状改变 ,常伴有高电子密度的块状沉积物。但 L - NNA治疗组脊髓神经元及大部分神经纤维的髓鞘结构清晰。因此我们认为 ,大鼠急性脊髓损伤可诱导神经元 NOS表达 ,L - NNA对其损伤修复起促进作用。

INFLUENCE OF L-NNA ON ACUTE SPINAL CORD INJURY IN THE RATS

Wistar rats were divided into three groups: normal control group, saline solution (NS) control group and L NNA therapeutic group Incomplete spinal cord injury model (218 gcf) were made in the last two groups After operation, the rats of L NNA group were injected with L NNA(20 mg/kg/d) for four weeks The rats of NS group were injected with equivalence NS Then the rats were killed for NOS staining and ultrastruture observation The results were as fololws: The NOS positive neurons of spinal cord were stained dark blue in NS group And the photodensity of NOS positive neurons in NS group is more high than that in L NNA group ( P <0 05) Ultrastructure observation showed the structure of the spinal cord neurons in NS group was changed, for example, cytoplasm vacuolation, mitochondrias and myelin sheath degeneration and so on But the structure of the spinal cord neurons and most part of myelin sheath remained clear in L NNA group Conclusion: Acute spinal cord injury of rat might induce expression of neuronal NOS Continuous application of L NNA might promote the repair of incomplete spinal cord trauma