On the cause for the urinary incontinence derived from overactive detrusor muscles : Analysis by morphological changes in cell junctions

老年人尿失禁的原因之一被认为是逼尿肌过度活动。应用微尖探头视频尿动力学方法对32例老年膀胱颈狭窄患者的逼尿肌功能进行了分析。此外，还观察了肾上腺素受体α特拉唑嗪对逼尿肌的作用。对光头颈狭窄症患者的活检标本进行了电子显微镜检查。用组织化学方法观察了膀胱逼尿肌中慢肌纤维和快肌纤维的分布规律及慢快肌纤维的比值。结果表明，大多数患者的膀胱颈收缩是器质性的，逼尿肌中肾上腺素受体α占优势，肾上腺素受体β占优势。电子显微镜显示，有下尿路症状的患者逼尿肌间隙连接呈营养不良状态，提示有下尿路症状的膀胱过度活动源于逼尿肌肌细胞间的间隙连接发育不良。快、慢肌纤维在犬逼尿肌中随机混合。未发现随年龄增长的特定分布格局。

One of the causes for the urinary incontinence in aged man is considered to be overactivity of the detrusor muscles. The function of detrusor muscles of 32 aged patients with bladder neck constracture were analysed by a video-urodynamics method using a microtip-transducer. The effects of terazosin, an adrenalin receptor α, on the detrusor muscle were also examined. Biopsy samples from patients with baldder neck constracture were also examined by electron microscopy. Distribution pattern of slow muscle fibers and fast muscle fibers and the ratio of slow to fast muscle fibers were examined by a histochemical method.The results showed that bladder neck constracture in most patients was organic, and the adrenalin receptor α was dominant to the adrenalin receptor β in the detrusor muscles in the patients with bladder neck constracture. Electron micrographs showed that the gap junctions in the detrusor muscles in the patients with lower urinary tract symptoms were hypotrophic, indicating that overactivity of the urinary bladder with lower urinary tract symptoms was derived from hypoplastic gap junctions between muscle cells in the detrusor. The fast and slow muscle fibers were mixed randomly in the detrusor muscles of the dog. A specific distribution pattern with aging was not found.