大鼠脊髓横断后逼尿肌的结构与功能变化

Changes of structures and functions in detrusor hyperreflexia in rats following spinal cord transection

目的 探讨脊髓横断后逼尿肌功能与结构变化的关系。方法 于L1～ 2 平面横断大鼠脊髓 ,3周后行膀胱压力容积测定和体外肌条拉力试验 ,同时使用光、电镜观察比较逼尿肌结构变化。结果 实验组大鼠膀胱体积、湿质量或是膀胱壁厚均较对照组明显增加。平滑肌细胞数量增多、体积增大 ,伴少量纤维增生。核内颗粒增多 ,胞浆内肌丝数量增多 ,细胞间可见大量锯齿状的胞突连接以及较多紧密连接。实验组为低顺应性和不稳定膀胱。在一定张力下逼尿肌有自发性收缩产生。实验组体外肌条自发性收缩频率及收缩力较对照组高。阿托品对肌条自发性收缩频率无影响。结论 逼尿肌反射亢进的形成有着其特殊的原因和病理生理变化 。

Objective To investigate the relationship between the changes of structures and functions of detrusor hyperreflexia. Methods Spinal cord transection(SCT) was performed in rats at the L1 2 level. In week 3 after transection, detection of the bladder pressure and volume and in vitro test of the tension of the detrusor strip were performed. Structure changes of the detrusor in SCT and control rats were monitored by cystometry and pathological changes in detrusor were observed with light and electron microscopes. Results The bladders of SCT group were larger and heavier than those of the control. The detrusor smooth muscle cells appeared hypertrophy. More gaps and protrusion junctions were found. Bladders of SCT rats showed lower capacity, lower compliance and hyperreflexia. Detrusors of rats in both groups contracted at definite tension. The contraction frequency in instable group was higher than that in stable group. Atropine had no effect on the spontaneous contraction of detrusor strips. Conclusion Detrusor hyperreflexia is resulted from specific causes and pathophysiological changes. The changes of functions and structures may attribute to the formation of detrusor instability.