脊髓背侧损伤大鼠排尿上行传导通路的改变

Changes of micturition upstream transduction pathway on dorsal spinal cord injury rats

目的采用生物素葡聚糖胺（BDA）示踪技术观察大鼠脊髓背侧损伤后排尿上行传导通路的改变。方法采用清洁级雌性SD大鼠30只,随机分为实验对照组和脊髓背侧损伤17 g/2 cm、17 g/5 cm及17 g/10cm,3个小组,使用该院自行设计的实验装置在T12-L1水平制备背侧脊髓损伤动物模型,对照组大鼠仅暴露脊髓,但不损伤脊髓。术后第1天,所有大鼠开腹,BDA注射于膀胱壁。BDA注射2周后取出脊髓组织,行BDA染色并观察其变化。结果神经示踪后BDA免疫组化阳性的神经元呈棕褐色深染。BDA阳性的神经元细胞主要分布在脊髓灰质。通过观察脊髓组织内BDA的变化情况,发现脊髓损伤后损伤部位以上脊髓组织内BDA阳性的神经元细胞数目较对照组减少;随着脊髓损伤程度的加重,神经元细胞染色程度减弱。并且在脊髓损伤组中,损伤部位以上出现一侧深染者,向上走行过程中观察到另一侧相应位置也出现明显BDA染色阳性的区域。结论 BDA示踪技术在神经传导的研究中有较好的应用价值。神经示踪结果提示外伤性脊髓损伤后膀胱尿道与排尿中枢间神经通路的传导发生了减弱,并且膀胱尿道与排尿中枢间神经通路在传导过程中存在神经支配向对侧交叉传导的情况。

【Objective】 To observe the changes of micturition upstream pathway on dorsal spinal cord injury rat by biotin dextran amine（BDA） anterograde neuronal tracing technique.【Methods】 30 Female SD rats of clean grade,were randomly divided into 4 groups.They are one control group and three dorsal spinal cord injury groups（17 g/2 cm,17 g/5 cm and 17 g/10 cm）.We prepared the dorsal spinal cord injury model by ourselves-designed device,and selected T12～L1 as the level of injury.In the control group,the spinal cord was identically exposed,but the spinal cord was not damaged.At the first postoperative day,all rats were cut abdomen,and injected BDA into bladder wall.Two weeks after BDA injection,spinal cord tissues were biopsy and stained and observed.【Results】 The BDA-positive neurons were deeply stained brown by the immunohistochemistry methods.BDA-positive neurons are mainly distributed in the spinal cord gray matter.Compared with the control group,we found that after spinal cord injury,the number of BDA-positive neurons decreased on the site of spinal cord tissue above the spinal cord injury site,and with the increase of the severity of spinal cord injury,the staining of BDA-positive neurons becomes lighter.We also find that in spinal cord injury group,above the injury site some model rat’s spinal cord tissue were deep stained at one side,but after some distance,we observed that the other side of the corresponding location is also obvious BDA stained area.【Conclusion】 The BDA tracing technique has a good value in the study of nerve conduction.Nerve tracer results suggest that the conduction of neural pathways between the bladder/urethra and micturition center become weakened after traumatic spinal cord injury.And there is cross-conduction in the neural pathways between the bladder/urethra and micturition center.