Groen J, van Mastrigt R, Bosch R
Department of Urology, Erasmus University, Rotterdam, The Netherlands.
Neurourol Urodyn. 1994;13(5):587-95. doi: 10.1002/nau.1930130514.
To study the relative importance of neurogenic factors in detrusor contractility and to relate a total bladder in vitro contractility model to a previously described bladder wall strip model, active intravesical pressure values were compared in situ and in vitro in eight male guinea pigs. In situ, the active pressure was measured in spontaneous isometric and non-isometric micturition contractions. In vitro, the active pressure was measured in isometric contractions of the same bladders, developed in response to optimal electrical stimulation. The volume dependence of the active pressure generated by the bladder was measured in vitro in order to relate bladder capacity to the volume where the generated force is maximal and to determine the optimal volume at which to study detrusor contractility. The results indicated that in normal micturition the detrusor muscle was not fully stimulated: active pressure in isometric contractions in vivo was about 60% of the pressure values attained in vitro at the same bladder volume. Most micturitions occurred at a volume where the active pressure generated in vitro was about 80% of the maximal pressure. The active pressure-bladder volume relationship complied with the sliding filament-cross bridge theory. In whole bladder preparations active stress was about twice as high as in strips.
为研究神经源性因素在逼尿肌收缩性中的相对重要性，并将全膀胱体外收缩性模型与先前描述的膀胱壁条带模型相关联，对8只雄性豚鼠的膀胱原位和体外的主动膀胱内压值进行了比较。在原位，测量了自发性等长和非等长排尿收缩时的主动压力。在体外，测量了相同膀胱在最佳电刺激下产生的等长收缩时的主动压力。在体外测量了膀胱产生的主动压力的体积依赖性，以便将膀胱容量与产生最大力的体积相关联，并确定研究逼尿肌收缩性的最佳体积。结果表明，在正常排尿时，逼尿肌未得到充分刺激：体内等长收缩时的主动压力约为相同膀胱体积下体外获得压力值的60%。大多数排尿发生在体外产生的主动压力约为最大压力80%的体积时。主动压力-膀胱体积关系符合滑行细丝-横桥理论。在全膀胱制备中，主动应力约为条带中的两倍。
