Partial outlet obstruction enhances modular autonomous activity in the isolated rat bladder
Partial outlet obstruction enhances modular autonomous activity in the isolated rat bladder
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DOI：
10.1097/01.ju.0000069722.35137.e0
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发表时间：
2003-07-01
影响因子：
6.6
通讯作者：
Gillespie, JI
中科院分区：
文献类型：
--
作者：
Drake, MJ;Hedlund, P;Gillespie, JI
目的：自主膀胱活动可以采取局部微运动（MM）的形式，这表明逼尿肌可能被排列成组成模块，其中每个模块都能够自主收缩。我们检查了分离的整个大鼠膀胱中的 MM 以及作为逼尿肌过度活动 (DO) 模型的部分膀胱出口梗阻的影响，以确定模块活动的改变是否可能是 DO 的病因因素。 材料和方法：总共 12 只成年雌性 Sprague-Dawley 大鼠接受梗阻或假手术 1 周或 4 周。通过显微外科手术取出膀胱并安装在整个器官组织浴中。在标准化条件下记录膀胱内压力并同时记录壁内收缩。结果：在填充之前，MM在假手术动物中表现为膀胱输尿管连接处附近的局部收缩，在梗阻动物中表现为多灶性微收缩。膀胱内容量的增加与传播收缩波的局部 MM 的变化有关。在假手术动物中，拉伸导致 MM 频率增加，但幅度降低。阻塞后拉伸引起高度协调的 MM 并增强膀胱内压力传递。手术后的时间没有改变假手术组或梗阻组的观察结果。结论：在模拟尿液储存的条件下，孤立膀胱中的逼尿肌可能具有功能性模块化排列，其中基底外侧区域在充盈之前最活跃。决定膀胱内压力的外周因素包括活跃模块的数量、协调性和其他部位的壁内张力。膀胱出口阻塞后，更多模块在基线处活跃，并且通过拉伸增强了它们的协调性，导致压力波动增加。这些变化可能有助于 DO 的发展。
Purpose: Autonomous bladder activity can take the form of localized micromotions (MMs), suggesting that the detrusor may be arranged into component modules, of which each is capable of contracting autonomously. We examined MMs in isolated whole rat bladder and the effects of partial bladder outlet obstruction as a model of detrusor overactivity (DO) to ascertain whether altered modular activity could be an etiological factor in DO.Materials and Methods: A total of 12 adult female Sprague-Dawley rats underwent obstruction or sham operation for 1 or 4 weeks. Bladders were microsurgically removed and mounted in whole organ tissue baths. Recordings of intravesical pressure and simultaneous registration of intramural contractions were performed under standardized conditions.Results: Prior to filling MMs took the form of localized contractions near the vesicoureteral junction in sham operated animals and multifocal microcontractions in obstructed animals. Intravesical volume increases were associated with a change in localized MMs to propagated contraction waves. In sham operated animals stretch resulted in increased MM frequency but decreased amplitude. After obstruction stretch elicited highly coordinated MMs and enhanced intravesical pressure transmission. The time since surgery did not alter observations in the sham or obstructed group.Conclusions: Detrusor muscle in isolated bladders under conditions modeling urine storage may have a functional modular arrangement with the basolateral region most active prior to filling. Peripheral factors determining intravesical pressure include the number of modules active, coordination and intramural tension at other sites. After bladder outlet obstruction more modules are active at baseline and their coordination is enhanced by stretch, leading to increased pressure fluctuations. Such changes may contribute to the development of DO.