Drake M J, Harvey I J, Gillespie J I
School of Surgical and Reproductive Sciences, 3rd floor Leech building, The Medical School, University of Newcastle, NE2 4HH, UK.
Exp Physiol. 2003 Jan;88(1):19-30. doi: 10.1113/eph8802473.
Phasic changes in pressure have been reported to occur in the bladder which are not associated with micturition. Spontaneous intravesical pressure changes can be recorded from bladders in vitro or bladders in vivo isolated from the central nervous system suggesting that the bladder itself is capable of autonomous activity. Experiments using isolated cells and muscle strips indicate that the smooth muscle can generate spontaneous activity. Whether this is the origin of phasic changes in the intact organ remains unknown. The present study set out to establish the presence and characteristics of autonomous activity in the isolated guinea pig bladder. Multiple-point motion analysis and concurrent intravesical pressure recording were used to identify and quantify spontaneous and evoked activity. Highly complex autonomous activity was observed in unstimulated bladders. This activity comprised localised micro-contractions in single or multiple discrete regions, waves of activity and micro-stretches. Low-amplitude phasic 'micro-transients' were seen in the intravesical pressure trace in association with micro-contractions. Incremental increases in the intravesical volume recruited additional areas of activity. Atropine and tetrodotoxin had no effect on the micro-transients or micro-contractions. Exposure to the muscarinic agonist arecaidine (10-300 nM) initially increased the incidence of micro-contractions which subsequently became co-ordinated into phasic pressure rises and contraction waves, interspersed with periods of total quiescence. The findings describe the generation and co-ordination of autonomous activity in the bladder wall and also demonstrate complex phasic activity. This approach has shown the importance of assessing the integrative properties of the entire organ in studies of the physiology and patho-physiology of the bladder.
据报道，膀胱中会出现与排尿无关的压力阶段性变化。自发性膀胱内压变化可在体外膀胱或与中枢神经系统分离的体内膀胱中记录到，这表明膀胱本身具有自主活动能力。使用分离细胞和肌肉条的实验表明，平滑肌能够产生自发活动。而这是否是完整器官中阶段性变化的起源仍不清楚。本研究旨在确定豚鼠离体膀胱自主活动的存在及其特征。采用多点运动分析和同步膀胱内压记录来识别和量化自发活动和诱发活动。在未受刺激的膀胱中观察到高度复杂的自主活动。这种活动包括单个或多个离散区域的局部微收缩、活动波和微拉伸。与微收缩相关的膀胱内压曲线上可见低振幅的阶段性“微瞬变”。膀胱内体积的逐渐增加会引发更多的活动区域。阿托品和河豚毒素对微瞬变或微收缩没有影响。暴露于毒蕈碱激动剂槟榔次碱（10 - 300 nM）最初会增加微收缩的发生率，随后这些微收缩会协同形成阶段性压力升高和收缩波，并穿插着完全静止的时期。这些发现描述了膀胱壁自主活动的产生和协调，也证明了复杂的阶段性活动。这种方法表明了在膀胱生理学和病理生理学研究中评估整个器官整合特性的重要性。
