What are the origins and relevance of spontaneous bladder contractions? ICI‐RS 2017

Drake, Marcus; Fry, Christopher; Hashitani, Hikaru; Kirschner‐Hermanns, Ruth; Rahnama’i, Mohammad Sajjad; Speich, John E.; Tomoe, Hikaru; McCloskey, Karen

doi:10.1002/nau.23485

Cited by 21 publications

(15 citation statements)

References 60 publications

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“…U&LP strips are known to exhibit spontaneous phasic contractions in the absence of any stimulation [47]. These spontaneous contractions that are thought to be propagated by the muscularis mucosae present within the U&LP [48][49][50] and which can be mediated by prostaglandin agonists observed in this study may have a modulatory role in the bladder function.…”

Section: Discussionmentioning

confidence: 57%

The five primary prostaglandins stimulate contractions and phasic activity of the urinary bladder urothelium, lamina propria and detrusor

Štromberga

Chess-Williams

Moro

2020

Preprint

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Background: Inflammation is often associated with several bladder dysfunctions, including overactive bladder (OAB) and interstitial cystitis/bladder pain syndrome (IC/PBS). As such, inflammation of the bladder and the actions of inflammatory mediators may contribute to the development of the urinary symptoms. This study assessed the actions of PGE 2 , PGF 2 , PGD 2 , TXA 2 , and PGI 2 on the urinary bladder urothelium with lamina propria (U&LP), as well as the detrusor smooth muscle.Methods: Studies were carried out using isolated tissue baths, where strips porcine bladder U&LP or detrusor were exposed to varying concentrations of prostaglandin agonists (1 µM and 10 µM).Results: All assessed prostaglandin agonists contracted both the U&LP and detrusor smooth muscle, with the rank order of contractile response effectiveness as: PGE 2 > PGF 2α > TXA 2 > PGD 2 > PGI 2 . In U&LP, treatment with PGE 2 (10 µM) increased tonic contractions by 1.36 ± 0.09 g (n = 42, p < 0.001) and phasic contractions by 40.4 ± 9.6% (n = 42, p < 0.001). In response to PGF 2α (10 µM), U&LP tonic contractions increased by 0.79 ± 0.06 g (n = 14, p < 0.001) and phasic activity by 13.3% ± 5.3% (n = 15, p < 0.05). In detrusor preparations, PGE 2 (10 µM) increased tonic contractions by 1.32 ± 0.13 g (n = 38, p < 0.001) and PGF 2α (10 µM) by 0.97 ± 0.14 g (n = 12, p < 0.001). Only 34% (n = 48) of all detrusor preparations exhibited spontaneous activity prior to the addition of any agonist at a frequency of 2.03 ± 0.12 cpm. In preparations that did not exhibit initial phasic activity, all of the prostaglandin agonists were capable of commencing phasic activity.Conclusions: The urinary bladder U&LP and detrusor respond to a variety of prostaglandin agonists, with their activation resulting in direct contractions, as well as increases to spontaneous contractile activity. This study presents the prostaglandin receptor system as a potential therapeutic target for lower urinary tract dysfunction.

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Section: Discussionmentioning

confidence: 57%

The five primary prostaglandins stimulate contractions and phasic activity of the urinary bladder urothelium, lamina propria and detrusor

Štromberga

Chess-Williams

Moro

2020

Preprint

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“…The physiological role of spontaneous contractions of the bladder is not wellunderstood, but it has been proposed to be important for maintaining the bladder tone and the dynamic elasticity for efficient voiding 18 . Non-voiding spontaneous bladder contractions are present in vivo in bladders across many species (mice, rats, pigs, rabbits, humans, etc.)…”

Section: Discussionmentioning

confidence: 99%

“…In order to perform nerve stimulation in awake SCI rats, we implanted a bipolar flexible neural clip 16,17 on the pelvic nerve, and used a prototype of a wireless nerve stimulator to deliver biphasic constant current pulses. Bladder size, capacity, and preservation of nonvoiding spontaneous contractions 18 were monitored and quantified. As the pelvic nerve also carries sensory afferents that convey information from mechanoreceptors and nociceptors within the bladder wall 1 , we also performed extraneural recordings from pelvic nerve using both commercial benchtop system as well as implantable neural amplifier to examine the possibility of using pelvic nerve signals as a proxy to estimate intravesical pressure changes for closed-loop applications 19 .…”

Section: Introductionmentioning

confidence: 99%

Neuromodulation of pelvic nerve during early phase of spinal cord injury in rats using implantable prototype devices - a preliminary study

Peh

Alam

Ahmed

et al. 2019

Preprint

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ObjectivesThe bladder becomes retentive during the early phase of spinal cord injury, and requires proper bladder management to prevent damage to the lower urinary tract and kidney. We investigated the effects of on-demand pelvic nerve stimulation on the areflexive bladder during the earliest phase of complete spinal cord injury in rats and the use of pelvic nerve signals as a proxy to estimate intravesical pressure for closed-loop applications. Materials and MethodsIn order to stimulate the pelvic nerves in female Sprague-Dawley rats with complete spinal cord transection (T7 level), a flexible electrode was implanted unilaterally on pelvic nerve, and electrical stimulation was provided by a custom-built nerve stimulator. Stimulationevoked voiding was monitored in the awake state while size, capacity and spontaneous contractions of the bladder were analysed under anaesthesia. Separately, recordings of the pelvic nerve signals, external urethral sphincter activity and intravesical pressure were performed in animals with intact and transected spinal cord under anaesthesia. ResultsSuccessful pelvic nerve stimulation enabled more frequent voiding, reduced overdistension of bladder, and preserved non-voiding spontaneous bladder contractions.Typical bladder management protocol for SCI rats (manual expression every 8 -12 hours) resulted in more severe bladder overdistention. Signal processing of the recorded extraneural pelvic nerve signals successfully reconstructed changes in intravesical pressure, demonstrating their use in estimating the fullness and contractions of the bladder. ConclusionsThe preliminary results suggest that pelvic nerve stimulators can serve as an alternative method for frequent emptying of the areflexive bladder. Simultaneous recording of the same pelvic nerve will be useful for development of a closed-loop neuroprosthesis.

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“…These micromotions were initially observed visually as autonomous activity in bladder strips and isolated bladder preparations. The role of these micromotions in normal and pathological bladder physiology in large animals and eventually humans could be further elucidated if adequate measurement tools are developed 5 …”

Section: Introductionmentioning

confidence: 99%

Novel implantable pressure and acceleration sensor for bladder monitoring

et al. 2020

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Objectives: To test the hypothesis that an implantable sensing system containing accelerometers can detect small-scale autonomous movements, also termed micromotions, which might be relevant to bladder physiology. Methods: We developed a 6-mm submucosal implant containing a pressure sensor (MS5637) and a triaxial accelerometer (BMA280). Sensor prototypes were tested by implantation in the bladders of Gottingen minipigs. Repeated awake voiding cystometry was carried out with air-charged catheters in a standard urodynamic set-up as comparators. We identified four phases of voiding similar to cystometry in other animal models based on submucosal pressure. Acceleration signals were separated by frequency characteristics to isolate linear acceleration from the baseline acceleration. The total linear acceleration was calculated by the root mean square of the three measurement axes. Acceleration activity during voiding was investigated to adjacent 1-s windows and was compared with the registered pressure. Results: We observed a total of 19 consecutive voids in five measurement sessions. A good correlation (r > 0.75) was observed between submucosal and catheter pressure in 14 of 19 premicturition traces. The peak-to-peak interval between maximum total linear acceleration was correlated with the interval between submucosal voiding pressure peaks (r = 0.760, P < 0.001). The total linear acceleration was higher during voiding compared with pre-and postmicturition periods (start of voiding/phase 1). Conclusions: To the best of our knowledge, this is the first report of bladder wall acceleration, a novel metric that reflects bladder wall movement. Submucosal sensors containing accelerometers can measure bladder pressure and acceleration.

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What are the origins and relevance of spontaneous bladder contractions? ICI‐RS 2017

Abstract: Deriving approaches to robust evaluation of spontaneous contractions and their influences for experimental and clinical use could yield considerable progress in functional urology.

Cited by 21 publications

References 60 publications

The five primary prostaglandins stimulate contractions and phasic activity of the urinary bladder urothelium, lamina propria and detrusor

The five primary prostaglandins stimulate contractions and phasic activity of the urinary bladder urothelium, lamina propria and detrusor

Neuromodulation of pelvic nerve during early phase of spinal cord injury in rats using implantable prototype devices - a preliminary study

Novel implantable pressure and acceleration sensor for bladder monitoring

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