脊髓损伤致神经源性膀胱尿动力检查及上尿路早期形态功能改变

Urodynamic monitoring in rats with neurogenic bladder induced by spinal cord injury

目的建造高位脊髓损伤所致神经源性膀胱的大鼠模型，研究神经源性膀胱排尿功能的变化及肾脏功能形态学的早期变化。方法60只雌性Wistar大鼠随机分为模型组和对照组。模型组于T10处横断脊髓，对照组只在相同平面暴露脊髓，不做横断。分别在术后6、10、14周对2组大鼠行尿动力学检测；取尿液检测尿酶NAG水平及细菌培养、鉴定；取血测尿素氮；取肾脏标本观察形态学变化。结果尿动力学检查模型组大鼠在膀胱充盈期表现为逼尿肌反射亢进、逼尿肌漏尿点压力增高、顺应性初期增高后随着造模时间延长逐渐下降。模型组大鼠均存在泌尿系感染，尿酶NAG增高明显。大体标本未见明显输尿管增粗、肾积水。光镜下可见肾盂上皮有炎性浸润，肾小管出现损害，间质可见灶状分布的纤维化，肾小球未见明显异常。电镜下见肾小管上皮细胞肿胀，细胞器减少，肾小管刷状缘、线粒体嵴排列紊乱，基底膜基本完整。结论脊髓损伤后神经源性膀胱排尿功能发生明显异常，肾小管间质病变在评价肾功能损害上比肾小球病理改变更有意义。

Objective To build the rat animal model of neurogenic bladder induced by spinal cord injury （SCI） and to investigate the changes of bladder and upper urinary tract function in this animal model. Methods A total of 60 female Wistar rats were randomly allocated into SCI group and sham group. Complete spinal cord transection was established by cutting out of dura at T10 in SCI group. The sham operation group was done only expose dura of T10 without transection. Urodynamic monitor was performed on rats at 6, 10 and 14 weeks. Urine was sent to do biochemistry examination, including NAG, bacteria count and culture. Blood was sent to detect BUN. Then put animals to death and take kidney specimens to do pathological examination. Results Urodynamic monitoring in rats revealed significant changes in the activity of the lower urinary tract after spinal cord transection. SCI rats exhibited detrusor hyperreflexia during bladder filling, higher leak point pressure, increased compliance at first and then decreased compliance compared with sham rats. All rats had urinary tract infection after the spinal cord injury. The level of NAG in SCI rats was increased. Hydroureterosis and hydronephrosis were not seen in SCI rats. Inflammatory infiltration in pelvis＇ epithelium and noticeable fibrous degeneration in interstitium were seen under light microscope, but glomcrulus was nearly norreal. Under electron microscope, swelled epithelial cells, decreased organelle, and disorderly arrangement of renal tubule brush border and mitochondrial crista were noted. Conclusions Neurogenic blad- der induced by spinal cord injury reveals significant changes in the activity of the lower urinary tract. Pathological changes of renal tubule and interstitium are more sensitive than glomcrulus in the evaluation of renal function.