Partial Outlet Obstruction Enhances Modular Autonomous Activity in the Isolated Rat Bladder

Drake, Marcus; Hedlund, Petter; Harvey, Ian J.; Pandita, Raj K.; Andersson, Karl Erik; Gillespie, James

doi:10.1097/01.ju.0000069722.35137.e0

Cited by 90 publications

(97 citation statements)

References 17 publications

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“…In the isolated detrusor muscle strip, this is reflected by increased amplitudes of the spontaneous contractions. 25 Corresponding contractions (as reflected by changes in intravesical pressure) can be observed in isolated perfused bladders 8,26 and in intact bladders during cystometry, even in humans. 27 The difficulty in observing such contractions during cystometry in the human bladder may be explained by their lack of coordination-some units are contracting when others are relaxing-and no consistent change in intravesical pressure is recorded.…”

Section: Intercellular Communicationmentioning

confidence: 99%

Detrusor myocyte activity and afferent signaling

Andersson

2009

Neurourology and Urodynamics

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Aims: To discuss (1) mechanisms involved in the generation and control of myocyte contractions and consequent afferent nerve activity and (2) these mechanisms as targets for drugs aimed for treatment of overactive bladder (OAB) symptoms and detrusor overactivity (DO). Methods: Literature review of myocyte activation, bladder afferent nerves, mediators in the bladder, and translational aspects of the findings. Results: During bladder filling, there is normally no parasympathetic outflow from the spinal cord. Despite this, the bladder develops tone during filling and also exhibits non-synchronized local contractions and relaxations that are caused by a basal myogenic mechanical activity that may be reinforced by release of, for example, acetylcholine from non-neuronal and/or neuronal sources or local mediators, such as prostaglandins and endothelins. It is suggested that these spontaneous contractions are able to generate activity in afferent nerves (''afferent noise'') that may contribute to DO and OAB. Conclusions: Spontaneous bladder myocyte contractions and factors that are able to modulate them, as well as the consequent afferent nerve activity, may be targets for drugs meant for treatment of OAB/DO. Neurourol.

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Section: Intercellular Communicationmentioning

confidence: 99%

Detrusor myocyte activity and afferent signaling

Andersson

2009

Neurourology and Urodynamics

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“…In contrast to micturition contractions, NVCs are most likely of myogenic origin since tetrodotoxin failed to block them in rats and guinea pigs alike (Maggi et al, 1987;Igawa et al, 1994). Both the amplitude and frequency of NVCs recorded in vivo and spontaneous contractions recorded in vitro are increased with bladder filling in control guinea pigs (Drake et al, 2003;Zagorodnyuk et al, 2009;Biallosterski et al, 2011). In the present study, the amplitude of spontaneous contractions and AUC of distensioninduced contractions of obstructed guinea pigs bladders in vitro were only slightly increased compared to shams.…”

Section: Bladder Contractions In Vitro and Non-voiding Contractions (mentioning

confidence: 58%

“…Thus our data suggest importance of the frequency, in addition to the amplitude, of NVCs in obstruction-induced bladder overactivity. Interestingly, in rats, the frequency of phasic contractions induced by distension of isolated obstructed bladders was lower compared to shams (Drake et al, 2003). This difference between rats and guinea pigs could be due to species, sex differences or to the amount of damage to the bladder neck area during surgery, which would affect the degree of obstruction.…”

Section: Bladder Contractions In Vitro and Non-voiding Contractions (mentioning

confidence: 97%

“…Obstruction-induced increase in spontaneous bladder contractions in vitro as well as in NVCs and voiding frequency in vivo has been demonstrated in many species (Sibley, 1987;Mostwin et al, 1991;Igawa et al, 1994;Drake et al, 2003;Kubota et al, 2008;Baker et al, 2010). NVCs recorded in vivo during urine storage phase in animal models are widely used as a surrogate marker for DO in humans.…”

Section: Bladder Contractions In Vitro and Non-voiding Contractions (mentioning

confidence: 99%

“…In the early stages of bladder outlet obstruction, partially obstructed animal bladder models closely mimic human DO and OAB. Notwithstanding the interspecies variability in morphological and functional properties of the bladder, the increases in spontaneous myogenic activity, non-voiding contractions and voiding frequency have been demonstrated in many species (Sibley, 1987;Mostwin et al, 1991;Igawa et al, 1994;Drake et al, 2003;Kubota et al, 2008;Baker et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Conscious voiding during bladder obstruction in guinea pigs correlates with contractile activity of isolated bladders

Nicholas

Keightley

Brookes

et al. 2015

Autonomic Neuroscience

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Purpose: There are many hypotheses accounting for detrusor overactivity, however the exact mechanisms are still incompletely understood. We used a model of bladder outlet obstruction in male guinea pigs as a way to produce detrusor overactivity. The objective was to determine whether changes in voiding of obstructed guinea pigs correlates with specific changes in contractile activity of their isolated bladders in vitro. Material and methods: Conscious voiding activity of sham-operated and obstructed animals was measured in metabolic cages. Contractile activity (spontaneous or evoked by distension, electrical field stimulation or cholinergic agonists) was recorded via a pressure transducer in the isolated bladders in vitro. Results: The frequency of conscious voiding increased (while voiding volume decreased) in the obstructed group, compared with the sham-operated group, 4 weeks after surgical intervention. In comparison to the sham-operated animals, the bladders from the obstructed guinea pigs were enlarged and inflamed, their frequency of spontaneous contractions was higher, while the amplitudes of electrical field stimulation (EFS)-induced contractions and bladder compliance were lower. Changes in conscious voiding during obstruction were significantly associated with alterations in structural parameters (bladder weight, thickness and histological damage score) and functional contractile parameters (frequency of spontaneous contractions, amplitude of EFS-induced contractions and bladder compliance) of their isolated bladders. Conclusions: Our findings revealed significant association between conscious voiding and structural and contractile activity changes of the isolated bladders in obstruction. The data suggest that change in contractile activity of the bladder itself is a major contributor to obstruction-induced bladder overactivity.

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Pathophysiology

Boudes¹,

Ridder²

2015

Overactive Bladder

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Partial Outlet Obstruction Enhances Modular Autonomous Activity in the Isolated Rat Bladder

Cited by 90 publications

References 17 publications

Detrusor myocyte activity and afferent signaling

Detrusor myocyte activity and afferent signaling

Conscious voiding during bladder obstruction in guinea pigs correlates with contractile activity of isolated bladders

Pathophysiology

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