外伤性背侧脊髓损伤对膀胱排尿神经通路的影响

Effects of traumatic dorsal spinal cord injury on cystic micturition nervous pathway

目的采用伪狂犬病毒(PRV)示踪技术观察大鼠背侧胸腰脊髓损伤(SCI)所致的膀胱排尿神经通路改变。方法清洁级雌性SD大鼠24只,采用随机数字表法分为2组:假手术组12只和背侧SCI损伤组12只。使用标准化SCI动物模型实验装置来制备动物模型,损伤部位定于T12～L1水平,假手术组大鼠仅咬除棘突及椎板,不损伤脊髓。SCI由背侧损伤脊髓,模型制备后,即刻对无SCI、SCI大鼠膀胱壁注射PRV,注射后96h直接取材,免疫组织化学方法显示大鼠脊髓切片中PRV阳性神经元。结果 PRV阳性神经元经免疫组织化学显色后呈棕黄色,观察切片SCI平面以上及以下均出现阳性神经元。SCI节段平面以上切片与对照组比较,阳性神经元显著减少;节段平面以下切片与对照组比较,阳性神经元增加。结论 SCI后,损伤导致受伤脊髓节段以上排尿反射通路受阻,进而SCI平面以下膀胱排尿反射通路发生代偿。

Objective To determine the changes in micturition nervous pathways induced by traumatic dorsal thoracolumbar spinal cord injury by using pseudorabies virus （PRV） tracer technique. Methods Twenty-four clean female SD rats were randomly assigned to sham operation group （n=12） and dorsal spinal cord injury group （group SCI, n=12）, respectively. A standardized dorsal spinal cord injury animal model was constructed based on the T12 to Ll injury. In sham operation group, the spinal process and lamina were removed while sparing the spinal cord. Rats in group SCI were subjected to spinal process and lamina removal. This was followed by PRV injection to the cystic wall that entailed extraction of the spinal cord at 96 h for assessment of the PRV-positive neurons by immunohistochem- istry assay. Results The PRV-positive neurons, labelled as browns-staining cells by immunohistochemistry assay, were noted above and below the injured planes of spinal cord injury, Compared with sham operation group, group SCI was associated with a significantly reduced and increased number of positive neurons in the plane above and below the injured spinal cord, respectively. Conclusion Traumatic spinal cord injury results in absence of micturition reflex conduction to the central nervous system yet augmented micturition reflex below the injured plane as a compensatory response.