Bladder compliance and detrusor activity during the collection phase

Abstract

The bladder wall is composed of passive (collagen, elaftin) and active (smooth muscle) elements. Some of the smooth muscle cells have properties of "pacemakers" in that they show spontaneous activity at rest. Moreover, when these cells are stretched, the resting membrane potentials decrease and the frequency of action potentials increase. It has been further demonstrated that both in vitro muscle strips and in vivo bladder preparations show spontaneous activity which may generate both tonic and phasic changes in bladder wall forces. The rate and duration of stretch both affect the force that the cell can generate. Thus, the filling pressureivolume curve obtained by systometry represents an interaction between the active and passive elements of the bladder wall. Since the cystornetric curve is time dependent, it is impossible to compare cystometrograms unless this time dependency is taken into account. With these principles in mind it is possible to standardize the terminology for characterizing detrusor activity during the collection phase as outlined in this report.

Pharmacology of the Lower Urinary Tract: Basis for Current and Future Treatments of Urinary Incontinence

“…It has been suggested that NO might be generated from the detrusor muscle and may be an important factor for bladder relaxation during the filling phase (James et al, 1993;Theobald, 1996). The normal bladder responds to filling at a physiological rate with relaxation and can accommodate large volumes of urine, with a minimal increase in intravesical pressure (Coolsaet, 1985). The phenomenon has been attributed not only to the physical properties of the bladder, but also to the existence of an inhibitory neural mechanism operative during filling and storage.…”

Evidence of increased centrally enhanced bladder compliance with ageing in a mouse model

“…Compliance is determined by the interaction of detrusor smooth muscle activity (active element) and the passive element of the extracellular matrix (ECM) [6]. By increasing tension in the bladder wall, detrusor muscular activity during filling increases pressure per volume, thus decreasing compliance, beyond that attributable to the ECM [7]. Passive factors affecting compliance, e.g.…”

Effects of inhibition of the l‐arginine/nitric oxide pathway in the rat lower urinary tract in vivo and in vitro

“…Normally, filling of the bladder occurs without any marked changes in intravesical pressure (Coolsaet, 1985). The mechanism is not known, but the behaviour has been attributed mainly to the physical properties of the detrusor muscle (Tang & Ruch, 1955;Klevmark, 1977).…”