A novel trauma induced urethral stricture in rat model.

Urethral stricture (US) is a longstanding disease, while there has not existed a suitable animal model to mimic the condition. We aimed to establish a trauma-induced US animal model to simulate this clinical scenario. A total of 30 rats were equally distributed into two groups, sham and US group. All rats were anesthetized with isoflurane and undergone cystostomy. In the US group, a 2 mm incision was made in the urethra and sutured to induce US. The sham group only make a skin incision on the ventral side of the anterior urethra. 4 weeks later, ultrasound and cystourethrography were performed to evaluate the degree of urethral stricture, pathological examinations were carried out to evaluate the degree of fibrosis. Urodynamic evaluation and mechanical tissue testing were performed to evaluate the bladder function and urethral tissue stiffness. The results showed that the urethral mucosa was disrupted and urethral lumen was stenosed in the US group. Additionally, the US group showed elevated bladder pressure, prolonged micturition intervals and increased tissue stiffness. In conclusion, the rat urethral stricture model induced by trauma provides a closer representation of the real clinical scenario. This model will significantly contribute to advancing research on the mechanisms underlying traumatic urethral stricture.

Improvement of neurogenic urinary dysfunctions in female rats treated with an injection of botulinum toxin A at the epicenter of the spinal cord injured site.

OBJECTIVE: To assess the effect of an injection of botulinum toxin A (BoNT/A) at the epicenter of the spinal cord injury (SCI) site on the recovery of lower urinary tract function in female rats with thoracic SCI. MATERIALS AND METHODS: Twenty-four female Wistar rats with Sham (laminectomy at T8/T9 level) or SCI (at T8/T9; 30 g compression for 5 s) were assigned into Sham-SS (injected with 5 µL of saline solution), Sham-BoNT/A (injected with 15 pg/rat, equivalent to 7.5 Units/kg of BoNT/A in 5 µL volume), SCI-SS (injured and injected with saline), SCI-BoNT/A (injured and injected with BoNT/A), N = 6 per group. Weekly evaluation of stereotyped micturition behavior, hind-limb nociception, and locomotor activity was performed 1 week before and during 6 weeks after surgery. Subsequently, all groups underwent simultaneous electromyography of the external urethral sphincter (EUS-EMG) and cystometric (CMG) studies. RESULTS: A compression SCI at the T8/T9 thoracic level significantly impairs sensory and locomotive functions, as well as stereotyped micturition behavior. However, these impairments were improved by BoNT/A injection after SCI. Neither injections of saline solution nor BoNT/A had an appreciable effect on the same parameters evaluated in the Sham groups. The combined EUS-EMG and CMG evaluations revealed important improvements of lower urinary tract physiology, particularly a reduction in the frequency of non-voiding contractions and the properties of EUS bursting activity indicated as the amplitude of the EUS-EMG signal and duration of burst electrical activity during effective voiding. CONCLUSION: The severe impairments on sensory and locomotive functions as well stereotyped micturition caused by an SCI could be potentially attenuated by an injection of a small amount of BoNT/A directly into the epicenter of the SCI region. A reduction in the release of neurotoxic neurotransmitters requiring the SNARE complex may be the mechanism triggered by BoNT/A to reduce neurotoxicity and hyperexcitability created in the SCI area to improve the survival of spinal cord cells involved in micturition.

Effects of parental holding on pain response in young children during cystometry: A randomized controlled trial.

INTRODUCTION: Cystometry is essential for evaluating bladder function. However, children may react negatively to the physical pain of urethral catheterization or anxiety and fear of an unfamiliar environment. These pain responses during the cystometry procedure may interfere with the cystometry procedure and make it difficult to interpret the cystometry result. In this regard, the International Children's Continence Society has advised performing cystometry while holding infants as an effective nonpharmacological pain management method, but there is insufficient evidence to support this. PURPOSE: This study aimed to analyze the effect of parental holding on reducing pain in children during cystometry. METHODS: This was an experimental study in a randomized controlled pre-post test design. A total of 64 participants aged 6-18 months were recruited. During cystometry, the participants in the experimental group were placed on the parent's laps and held in the parents' arms. The participants in the control group were laid down on the examination table. During the procedure, both groups of parents were allowed to touch their children in all ways except holding them and to use the pacifier if they wished. The behavioral (face, leg, activity, cry, consolability scale) and physiological (oxygen saturation and heart rate) pain responses were measured at three-time points (immediately, 3, and 10 min after urethral catheter insertion). RESULTS: Comparing the two groups, in the experimental group, the behavioral pain response at 3 min after urethral catheter insertion (t = -2.165, p = 0.034) and 10 min after (t = -3.155, p = 0.002) was decreased compared with that immediately after urethral catheter insertion. In addition, oxygen saturation increased more (t = 2.021, p = 0.048), and the heart rate decreased more (t = -2.033, p = 0.047) at 10 min than at 3 min after urethral catheter insertion in the experimental group. CONCLUSIONS: This study revealed that parental holding could reduce pain responses during cystometry in children. Further research is required to confirm the applicability and usefulness of parental holding during cystometry.

TRPA1 channel mediates methylglyoxal-induced mouse bladder dysfunction.

Introduction: The transient receptor potential ankyrin 1 channel (TRPA1) is expressed in urothelial cells and bladder nerve endings. Hyperglycemia in diabetic individuals induces accumulation of the highly reactive dicarbonyl compound methylglyoxal (MGO), which modulates TRPA1 activity. Long-term oral intake of MGO causes mouse bladder dysfunction. We hypothesized that TRPA1 takes part in the machinery that leads to MGO-induced bladder dysfunction. Therefore, we evaluated TRPA1 expression in the bladder and the effects of 1 h-intravesical infusion of the selective TRPA1 blocker HC-030031 (1 nmol/min) on MGO-induced cystometric alterations. Methods: Five-week-old female C57BL/6 mice received 0.5% MGO in their drinking water for 12 weeks, whereas control mice received tap water alone. Results: Compared to the control group, the protein levels and immunostaining for the MGO-derived hydroimidazolone isomer MG-H1 was increased in bladders of the MGO group, as observed in urothelium and detrusor smooth muscle. TRPA1 protein expression was significantly higher in bladder tissues of MGO compared to control group with TRPA1 immunostaining both lamina propria and urothelium, but not the detrusor smooth muscle. Void spot assays in conscious mice revealed an overactive bladder phenotype in MGO-treated mice characterized by increased number of voids and reduced volume per void. Filling cystometry in anaesthetized animals revealed an increased voiding frequency, reduced bladder capacity, and reduced voided volume in MGO compared to vehicle group, which were all reversed by HC-030031 infusion. Conclusion: TRPA1 activation is implicated in MGO-induced mouse overactive bladder. TRPA1 blockers may be useful to treat diabetic bladder dysfunction in individuals with high MGO levels.

The Assessment of the Efficacy of Imperatorin in Reducing Overactive Bladder Symptoms.

Overactive bladder syndrome (OAB) is a prevalent condition that affects the elderly population in particular and significantly impairs quality of life. Imperatorin, a naturally occurring furocoumarin, possesses diverse pharmacological properties that warrant consideration for drug development. The aim of this study was to investigate the potential of imperatorin (IMP) to attenuate the cystometric and biochemical changes typically associated with retinyl acetate-induced overactive bladder (OAB) and to assess its viability as a pharmacological intervention for OAB patients. A total of 60 rats were divided into four groups: I-control, II-rats with rapamycin (RA)-induced OAB, III-rats administered IMP at a dose of 10 mg/kg/day, and IV-rats with RA-induced OAB treated with IMP. IMP or vehicle were injected intraperitoneally for 14 days. The cystometry and assessment of bladder blood flow were performed two days after the last dose of IMP. The rats were then placed in metabolic cages for 24 h. Urothelial thickness measurements and biochemical analyses were performed. Intravesical infusion of RA induced OAB. Notably, intraperitoneal administration of imperatorin had no discernible effect on urinary bladder function and micturition cycles in normal rats. IMP attenuated the severity of RA-induced OAB. RA induced increases in urothelial ATP, calcitonin gene-related peptide (CGRP), organic cation transporter 3 (OCT3), and vesicular acetylcholine transporter (VAChT), as well as significant c-Fos expression in all micturition areas analyzed, which were attenuated by IMP. Furthermore, elevated levels of Rho kinase (ROCK1) and VAChT were observed in the detrusor, which were reversed by IMP in the context of RA-induced OAB in the urothelium, detrusor muscle, and urine. Imperatorin has a mitigating effect on detrusor overactivity. The mechanisms of action of IMP in the bladder appear to be diverse and complex. These findings suggest that IMP may provide protection against RA-induced OAB and could potentially develop into an innovative therapeutic strategy for the treatment of OAB.

Repeated variate stress increased voiding frequency and altered TrpV1 and TrpV4 transcript expression in lower urinary tract (LUT) pathways in female mice.

Psychological stress is associated with urinary bladder dysfunction (e.g., increased voiding frequency, urgency and pelvic pain); however, the mechanisms underlying the effects of stress on urinary bladder function are unknown. Transient receptor potential (TRP) channels (vanilloid family) may be potential targets for intervention due to their distribution in the LUT and role in pain. Here, we examine a model of repeated variate stress (RVS) of 2 week (wk) or 4 wk duration in female mice and its effects on bladder function, anxiety-like behavior, and TRPV transcript expression in urinary bladder and lumbosacral spinal cord and associated dorsal root ganglia (DRG). Using continuous infusion, open-outlet cystometry in conscious mice, RVS significantly (p ≤ 0.05) decreased infused volume and intermicturition interval. Bladder pressures (threshold, average, minimum, and maximum pressures) were unchanged with RVS. Quantitative PCR demonstrated significant (p ≤ 0.05) changes in TrpV1 and TrpV4 mRNA expression between control and RVS cohorts in the urothelium, lumbosacral spinal cord, and DRG. Future directions will examine the contribution of TRP channels on bladder function, somatic sensation and anxiety-like behavior following RVS.

Lack of expression of miR-29a/b1 impairs bladder function in male mice.

Lower urinary tract symptoms (LUTS) refer to various urological diseases, and incomplete bladder emptying is common among affected patients. The etiology of LUTS is largely unknown, and investigations of LUTS suggest that bladder fibrosis contributes to pathogenesis of LUTS. MicroRNAs (miRNAs) are short (∼22 nucleotides), non-coding RNAs that repress target gene expression by a combination of mRNA degradation and translation inhibition. The miR-29 family is best known for its anti-fibrotic role in various organs. miR-29 was decreased in bladders of patients with outlet obstruction and a rat model of bladder outlet obstruction, suggesting that miR-29 may contribute to impaired bladder function subsequent to tissue fibrosis. We characterized bladder function in male mice lacking expression of Mir29a and Mir29b-1 (miR-29a/b1). Lack of miR-29a/b1 resulted in severe urinary retention, increased voiding duration and reduced flow rate, and these mice failed to void or voided irregularly during anesthetized cytometry. Collagens and elastin were increased in bladders of mice lacking miR-29a/b1. These findings reveal an important role for miR-29 in bladder homeostasis and suggest the therapeutic potential of miR-29 to improve symptoms in patients with LUTS.

Possible involvement of brain hydrogen sulphide in the inhibition of the rat micturition reflex induced by activation of brain alpha7 nicotinic acetylcholine receptors.

We previously reported that brain α7 nicotinic acetylcholine receptors inhibited the rat micturition reflex. To elucidate the mechanisms underlying this inhibition, we focused on the relationship between α7 nicotinic acetylcholine receptors and hydrogen sulphide (H2S) because we found that H2S also inhibits the rat micturition reflex in the brain. Therefore, we investigated whether H2S is involved in the inhibition of the micturition reflex induced by the activation of α7 nicotinic acetylcholine receptors in the brain. Cystometry was performed in male Wistar rats under urethane anesthesia (0.8 g/kg, ip) to examine the effects of icv pre-treated GYY4137 (H2S donor, 1 or 3 nmol/rat) or aminooxyacetic acid (AOAA; non-selective H2S synthesis inhibitor, 3 or 10 µg/rat) on PHA568487 (α7 nicotinic acetylcholine receptor agonist, icv)-induced prolongation of intercontraction intervals. PHA568487 administration at a lower dose (0.3 nmol/rat, icv) had no significant effect on intercontraction intervals, while under pre-treatment with GYY4137 (3 nmol/rat icv), PHA568487 (0.3 nmol/rat, icv) significantly prolonged intercontraction intervals. PHA568487 at a higher dose (1 nmol/rat, icv) induced intercontraction interval prolongation, and the PHA568487-induced prolongation was significantly suppressed by AOAA (10 µg/rat, icv). The AOAA-induced suppression of the PHA568487-induced intercontraction interval prolongation was negated by supplementing H2S via GYY4137 at a lower dose (1 nmol/rat, icv) in the brain. GYY4137 or AOAA alone showed no significant effect on intercontraction intervals at each dose used in this study. These findings suggest a possible involvement of brain H2S in inhibiting the rat micturition reflex induced by activation of brain α7 nicotinic acetylcholine receptors.

Assessing Neurogenic Lower Urinary Tract Dysfunction after Spinal Cord Injury: Animal Models in Preclinical Neuro-Urology Research.

Neurogenic bladder dysfunction is a condition that affects both bladder storage and voiding function and remains one of the leading causes of morbidity after spinal cord injury (SCI). The vast majority of individuals with severe SCI develop neurogenic lower urinary tract dysfunction (NLUTD), with symptoms ranging from neurogenic detrusor overactivity, detrusor sphincter dyssynergia, or sphincter underactivity depending on the location and extent of the spinal lesion. Animal models are critical to our fundamental understanding of lower urinary tract function and its dysfunction after SCI, in addition to providing a platform for the assessment of potential therapies. Given the need to develop and evaluate novel assessment tools, as well as therapeutic approaches in animal models of SCI prior to human translation, urodynamics assessment techniques have been implemented to measure NLUTD function in a variety of animals, including rats, mice, cats, dogs and pigs. In this narrative review, we summarize the literature on the use of animal models for cystometry testing in the assessment of SCI-related NLUTD. We also discuss the advantages and disadvantages of various animal models, and opportunities for future research.

Acute ampakines increase voiding function and coordination in a rat model of SCI.

Neurogenic bladder dysfunction causes urological complications and reduces the quality of life in persons with spinal cord injury (SCI). Glutamatergic signaling via AMPA receptors is fundamentally important to the neural circuits controlling bladder voiding. Ampakines are positive allosteric modulators of AMPA receptors that can enhance the function of glutamatergic neural circuits after SCI. We hypothesized that ampakines can acutely stimulate bladder voiding that has been impaired due to thoracic contusion SCI. Adult female Sprague Dawley rats received a unilateral contusion of the T9 spinal cord (n=10). Bladder function (cystometry) and coordination with the external urethral sphincter (EUS) were assessed five days post-SCI under urethane anesthesia. Data were compared to responses in spinal intact rats (n=8). The "low impact" ampakine CX1739 (5, 10, or 15 mg/kg) or vehicle (HPCD) was administered intravenously. The HPCD vehicle had no discernable impact on voiding. In contrast, following CX1739, the pressure threshold for inducing bladder contraction, voided volume, and the interval between bladder contractions were significantly reduced. These responses occurred in a dose-dependent manner. We conclude that modulating AMPA receptor function using ampakines can rapidly improve bladder voiding capability at sub-acute time points following contusion SCI. These results may provide a new and translatable method for therapeutic targeting of bladder dysfunction acutely after SCI.

Determination of tibial somatosensory evoked potentials predicts detrusor sphincter dyssynergia in children with neurogenic bladder dysfunction.

INTRODUCTION: Tibial somatosensory evoked potentials (SEP) are used to identify the neurological status and tethered cord (TC) in patients with spina bifida (SB). Its significance in contributing to the interpretation of urodynamics to determine bladder status is unknown. This study aimed to determine the correlation between SEP and urodynamics in children with SB. MATERIAL AND METHODS: SEP and urodynamic results, for differential diagnosis of TC, were evaluated. SEP scores were correlated with urodynamic findings. SEP results were scored from 1 to 6, with 1, denoting a favorable score and 6, an unfavorable score. Age, gender, detrusor, and sphincter activities in urodynamics were noted. Results were analyzed using the χ2 test and logistic regression analysis. Receiver operating characteristic (ROC) curve was formed to get a valid threshold for the SEP score to predict the urodynamic condition. RESULTS: There were 44 SB patients for whom SEP was done for differential diagnosis of TC. Fifteen patients who did not meet the inclusion criteria were excluded from the study. SB aperta was present in 17 patients and occulta in 12, respectively. The patients had a mean age of 6.6 ± 3.2 years. There were 13 boys and 16 girls. A strong correlation was found between high SEP scores and detrusor sphincter dyssynergia (p < 0.001). A SEP score over 3.5 was found to be 93% sensitive and 73% specific to predict this correlation. There was no relationship between detrusor activity and SEP scores (p = 0.18). DISCUSSION: Tibial SEP is an important noninvasive adjunct tool for the diagnosis of TC in patients with SB. Urodynamic studies are the gold standard in the evaluation of bladder status in neurogenic bladder dysfunction due to SB. Detrusor sphincter dyssynergia may be regarded as a sign of severe spinal cord injury in these patients. CONCLUSION: Our findings suggest that in children with neurogenic bladder, high SEP scores may predict the presence of detrusor sphincter dyssynergia but not the status of detrusor function while providing pathophysiological evidence for neural injury.

Imaging neuro-urodynamics of mouse major pelvic ganglion with a micro-endoscopic approach.

Postganglionic neurons of the autonomic nervous system lie outside of the central nervous system and innervate specific target effectors such as organs or glands. The major pelvic ganglion (MPG) is one such ganglion that plays a significant role in controlling bladder function in rodents. However, because of technical and physical constraints in recording electrophysiological signals from these neurons in vivo, the functional neural activity in MPG is mostly unknown. Transgenic animal models expressing genetically encoded calcium indicators now provide opportunities to monitor the activity of populations of neurons in vivo to overcome these challenges related to traditional electrophysiological methods. However, like many peripheral neurons, the MPG is not conducive to conventional fluorescent microscopy techniques, as it is located in the pelvic cavity, thus limiting robust optical access by benchtop microscopes. Here, we present an endoscopic approach based on a custom miniscope system (UCLA V3) that allows for effective in vivo monitoring of neural activity in the MPG for the first time. We show that our imaging approach can monitor activity of hundreds of MPG neurons simultaneously during the filling and emptying of the bladder in a urethane-anesthetized transgenic mouse line expressing GCaMP6s in cholinergic MPG neurons. By using custom analysis scripts, we isolated the activity of hundreds of individual neurons and show that populations of neurons have distinct phasic activation patterns during sequential bladder filling and voiding events. Our imaging approach can be adapted to record activity from autonomic neurons across different organs and systems in both healthy and disease models.NEW & NOTEWORTHY The functional activity and information processing within autonomic ganglia is mostly unknown because of technical and physical constraints in recording electrophysiological signals from these neurons in vivo. Here, we use a micro-endoscopic approach to measure in vivo functional activity patterns from a population of autonomic neurons controlling bladder function for the first time. This approach can be adapted to record activity from autonomic neurons across different organs and systems in both healthy and disease models.

Changes of bladder morphology and function and effect on upper urinary tract dilatation at different time after lumbosacral nerve transecting in rats / 中华泌尿外科杂志

Objective:To investigate the changes in the morphology, structure and function of the bladders and their effects on the upper urinary tract dilatation(UUTD) after lumbosacral nerve transecting in rats.Methods:A total of 45 female SD rats were included, randomly divided into 3 groups with 15 rats in each group. Two groups were performed bilateral lumbar 6(L6) and cauda equina nerve shearing to establish neurogenic bladder(NB) model, which were nerve transected for 4 weeks(NB-4W) group and nerve transected for 12 weeks(NB-12W) group. Another group was performed bilateral L6 nerves and cauda equine exposing but not transecting, which was sham-operation (Sham) group. Cystometry and renal ultrasound examination were performed and rats in each group were killed to collect the kidney and bladder tissues in NB-4W group at 4 weeks, in Sham group and NB-12W group at 12 weeks after operation. HE, Masson staining, immunohistochemical staining and western blot were used to detect histological changes, expression of transforming growth factor-β1(TGF-β1) and α-smooth muscle actin(α-SMA).Results:All rats in NB-4W and NB-12W group showed acontractile detrusor. In the NB-4W and NB-12W group, the maximum cystometric capacity [(5.84±0.33) ml and (3.13±0.35) ml], the detrusor leak point pressure [(25.41±0.86) cm H 2O and (27.36±2.04) cm H 2O] (1 cm H 2O = 0.098 kPa), were significantly higher than those in the Sham group [(0.98±0.14) ml, (7.13±0.90) cm H 2O, both P<0.05]. Compliance in NB-4W group [(0.28±0.21) ml/cm H 2O] and NB-12W group [(0.17±0.12) ml/cm H 2O] were significantly lower than that of the Sham group [(0.34±0.26) ml/cm H 2O], and the compliance of NB-12W group was lower than that of NB-4W group significantly (all P<0.05). HE staining of the bladder showed that the inflammatory cell infiltration was obvious in the NB-4W and NB-12W group. Bladder collagen volume fractions in NB-4W group [(30.5±1.5) %] and NB-12W group [(45.2±3.8) %] were both higher than that of Sham group [(20.7±2.2) %, both P<0.05]. The expression of TGF-β1 and α-SMA in the bladder tissue of NB-4W group were higher than those of sham group, and that of NB-12W group were higher than NB-4W group. In NB-4W group and NB-12W group, 3 (20.0 %) and 7 (46.7 %) rats were found hydronephrosis, respectively. Additionally, HE staining showed that the degree of renal tubule injury and the number of inflammatory cell infiltration in the NB-4W and NB-12W group were higher than those in the Sham group. Masson staining showed that the volume fraction of collagen in kidneys of NB-4W and NB-12W group were (13.1±1.4) % and (21.6±1.9) %, respectively, which were significantly higher than that in sham operation group [(4.6±0.7) %, both P<0.05]. Conclusions:Bilateral L6 + cauda equina nerve transecting can induce NB with hydronephrosis in parts of rats. The degree of bladder fibrosis gradually increased with the time of nerve transection, and the incidence and severity of UUTD also increased with the time of nerve transection.

Blockade of vasopressin receptors reduces the threshold pressure of micturition reflex in female rats.

The mechanisms involved in urinary bladder control are not fully understood, but it is well accepted that a complex central network is involved in micturition control. The micturition reflex can be modulated by direct cortical influence through facilitatory and inhibitory mechanisms. In addition, humoral mechanisms are involved in the bladder control. Vasopressin increases bladder contraction and intravesical pressure. This study sought to investigate the effect of intravenous injections of vasopressin receptor antagonists on cystometric parameters in anesthetized female rats. Isoflurane anesthetized adult female Wistar rats underwent femoral artery and vein cannulation for arterial pressure (AP) and heart rate (HR) recordings, and infusion of drugs, respectively. The bladder was also cannulated for intravesical pressure (IP) recordings and infusion of saline (10 mL/h) for cystometric evaluation. After baseline AP, HR and IP recordings, saline (vehicle, 1 mL/kg), V1a (5 µg/kg) or V2 receptor antagonist (5 µg/kg) was injected i.v. and after 25 min the cystometry was carried out. Neither saline nor V1a or V2 receptor blockade evoked any change in AP, HR and IP. Nevertheless, during cystometry, the threshold pressure of the micturition reflex was significantly reduced in rats with V1a (to 19.30 ± 2.39 mmHg) and V2 receptor blockade (to 19.88 ± 2.49 mmHg) compared to the saline group (28.85 ± 2.06 mmHg, p = 0.014). No difference was observed in the other cystometric parameters. Therefore, the data suggest that blockade of V1a and V2 receptors reduces the threshold pressure of the micturition reflex and does not influence other cystometric parameters in anesthetized female Wistar rats.

Machine learning-assisted fluoroscopy of bladder function in awake mice.

Understanding the lower urinary tract (LUT) and development of highly needed novel therapies to treat LUT disorders depends on accurate techniques to monitor LUT (dys)function in preclinical models. We recently developed videocystometry in rodents, which combines intravesical pressure measurements with X-ray-based fluoroscopy of the LUT, allowing the in vivo analysis of the process of urine storage and voiding with unprecedented detail. Videocystometry relies on the precise contrast-based determination of the bladder volume at high temporal resolution, which can readily be achieved in anesthetized or otherwise motion-restricted mice but not in awake and freely moving animals. To overcome this limitation, we developed a machine-learning method, in which we trained a neural network to automatically detect the bladder in fluoroscopic images, allowing the automatic analysis of bladder filling and voiding cycles based on large sets of time-lapse fluoroscopic images (>3 hr at 30 images/s) from behaving mice and in a noninvasive manner. With this approach, we found that urethane, an injectable anesthetic that is commonly used in preclinical urological research, has a profound, dose-dependent effect on urethral relaxation and voiding duration. Moreover, both in awake and in anesthetized mice, the bladder capacity was decreased ~fourfold when cystometry was performed acutely after surgical implantation of a suprapubic catheter. Our findings provide a paradigm for the noninvasive, in vivo monitoring of a hollow organ in behaving animals and pinpoint important limitations of the current gold standard techniques to study the LUT in mice.

Healthy adults empty their bladder many times a day with little thought. This seemingly simple process requires communication between the lower urinary tract and the central nervous system. About one in five adults experience conditions like urinary incontinence, urgency, or bladder pain caused by impairments in their lower urinary tract. Despite the harmful effects these conditions have on people's health and well-being, few good treatments are available. Mice are often used to study lower urinary tract conditions and treatments. One common technique is to fill a mouse's bladder using a catheter and measure changes in pressure as the bladder empties and refills. But these procedures and the anesthesia used during them may affect bladder function and skew results. Here, De Bruyn et al. have developed a new technique that allows scientists to measure bladder function in awake, freely moving mice. The mice's bladders were photographed using a specialized X-ray based fluoroscope that captured 30 images per second over the course of three hours. A machine learning algorithm was then applied which can automatically detect the circumference of the bladder in each captured image (over 30,000 in total) and quantify its volume. This makes it is possible to measure the bladder as it empties and fills even if the mice move between time frames. The new approach showed that 'gold standard' commonly used methods have a profound effect on the bladder. Surgical implantation of a catheter reduced the bladder to a quarter of its capacity. In addition, one of the most widely used anesthetic drugs in urinary tract research was found to affect the bladder's ability to drain. The technique created by De Bruyn et al. provides a new way to study lower urinary tract function and disease in awake, moving animals. This tool would be easy for other academic and pharmaceutical laboratories to implement, and may help scientists discover new therapies for lower urinary tract conditions.

The efficacy of nebivolol on spontaneously hypertensive rats with overactive bladder - an experimental study.

Introduction: Overactive bladder (OAB) is a disease that significantly decreases quality of life. Adverse effects of the drugs currently used in OAB treatment limit their use in patients with hypertension. Nebivolol (a ß1-adrenergic receptor blocker) is approved for hypertension treatment, but also shows agonistic activity on ß3-adrenergic receptor, located in the urinary bladder. The aim of this study was to assess the impact of nebivolol on OAB symptoms and cardiovascular parameters in spontaneously hypertensive rats (SHR) - an animal model of OAB and hypertension. Material and methods: Female Wistar-Kyoto (WHY) and SHR rats were used in the experiments. Nebivolol was administered intra-arterially at a single daily dose of 0.05 mg/kg for 14 days. Subsequently, cystometry and bladder blood flow assessment were performed. Then, 24-hour measurement of heart rate, blood pressure, and urine production was carried out. In addition, the bladders of experimental rats were removed and processed to conduct biochemical analyses. Results: The main finding of this study is that the treatment with nebivolol resulted in an improvement of cystometric parameters characteristic for OAB in SHR. Nebivolol normalised blood pressure in SHR, while in WHY the cardiovascular parameters remained unchanged. Biomarkers characteristic for OAB were elevated in SHR compared to WHY, and nebivolol decreased their values in SHR while it had no influence on WHY. Conclusions: Nebivolol alleviates OAB symptoms and normalises blood pressure in SHRs. These results suggest that nebivolol may be a useful treatment alternative for OAB patients with pre-existing hypertension.

[Is pressure transmission quality during cystometry dependent on the type of effort?] / La qualité de transmission des pressions pendant la cystomanométrie est-elle dépendante du type d'effort ?

INTRODUCTION: The International Continence Society (ICS) recommends a control of the good pressure transmission by a coughing effort during cystometry. While poor transmission is sometimes observed in routine practice, other maneuvers can also be proposed. The main objective of this study was to determine if there is a better maneuver to evaluate the pressure transmission ratio between the abdominal cavity and the bladder. METHODS: We performed a prospective, consecutive, single-center study in a tertiary neuro-urology department in 31 subjects. During a cystometry, each patient was asked to perform at 0ml and 100ml of bladder filling, a cough effort, an abdominal push and a Valsalva maneuver controlled by a manometer. The value of the bladder pressure to abdominal pressure ratio was collected manually. The average variations were compared between each maneuver for the same volume of replenishment and between the 2 volumes of replenishment studied. RESULTS: At 0ml of filling, the difference in pressure variation between the Pves and the Pabd is significantly higher during the cough maneuver compared to the Valsalva (P=0.015), which is not found at 100ml of filling. CONCLUSION: During bladder filling, the pressure transmission ratios during the 3 maneuvers are equivalent. Coughing or abdominal thrusting, which are easier to perform than the Valsalva maneuver, should be recommended to check the quality of the recording during cystomanometry.

Ventrolateral Periaqueductal Gray Neurons Are Active During Urination.

The ventrolateral periaqueductal gray (VLPAG) is thought to be the main PAG column for bladder control. PAG neurons (especially VLPAG neurons) and neurons in the pontine micturition center (PMC) innervating the bladder detrusor have anatomical and functional synaptic connections. The prevailing viewpoint on neural control of the bladder is that PAG neurons receive information on the decision to void made by upstream brain regions, and consequently activate the PMC through their direct projections to initiate urination reflex. However, the exact location of the PMC-projecting VLPAG neurons, their activity in response to urination, and their whole-brain inputs remain unclear. Here, we identified the distribution of VLPAG neurons that may participate in control of the bladder or project to the PMC through retrograde neural tracing. Population Ca2+ signals of PMC-projecting VLPAG neurons highly correlated with bladder contractions and urination as shown by in vivo recording in freely moving animals. Using a RV-based retrograde trans-synaptic tracing strategy, morphological results showed that urination-related PMC-projecting VLPAG neurons received dense inputs from multiple urination-related higher brain areas, such as the medial preoptic area, medial prefrontal cortex, and lateral hypothalamus. Thus, our findings reveal a novel insight into the VLPAG for control of bladder function and provide a potential therapeutic midbrain node for neurogenic bladder dysfunction.

Imatinib Mesylate Reduces Voiding Frequency in Female Mice With Acute Cyclophosphamide-Induced Cystitis.

Lamina propria interstitial cells that express the tyrosine kinase receptor, platelet-derived growth factor receptor alpha (PDGFRα) may play a role in urinary sensory signaling. Imatinib mesylate, also referred to as imatinib, is a tyrosine kinase inhibitor that can inhibit PDGFRα and has been widely used in urological research. We evaluated the functional effects of imatinib administration (via oral gavage or intravesical infusion) with two different experimental designs (prevention and treatment), in a cyclophosphamide (CYP)-induced cystitis (acute, intermediate, and chronic), male and female rodent model using conscious cystometry and somatic sensitivity testing. Imatinib significantly (0.0001 ≤ p ≤ 0.05) decreased voiding frequency and increased bladder capacity in acute CYP-induced cystitis, by the prevention (females) and treatment (females and males) designs. Imatinib was not effective in preventing or treating intermediate or chronic CYP-induced cystitis in either sex. Interestingly, in the prevention experiments, imatinib administration increased (0.0001 ≤ p ≤ 0.01) voiding frequency and decreased bladder capacity in control mice. However, in the treatment experiments, imatinib administration decreased (0.01 ≤ p ≤ 0.05) voiding frequency and increased bladder capacity in control mice. Bladder function improvements observed with imatinib treatment in acute CYP-induced cystitis mice remained and additionally improved with a second dose of imatinib 24 hours after CYP treatment. Imatinib administration did not affect pelvic somatic sensitivity in female mice with acute CYP-induced cystitis. Our studies suggest that (1) imatinib improves bladder function in mice with acute CYP-induced cystitis with a prevention and treatment design and (2) interstitial cells may be a useful target to improve bladder function in cystitis.

Superior therapeutic activity of TGF-ß-induced extracellular vesicles against interstitial cystitis.

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic disease characterized by incapacitating pelvic pain. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) are considered key mediators of the paracrine action of MSCs and show better biological activities than the parent MSCs, especially in the bladder tissue, which may be unfavorable for MSC survival. Here, we produced MSC-EVs using advanced three-dimensional (a3D) culture with exogenous transforming growth factor-ß3 (TGF-ß3) (T-a3D-EVs). Treatment with T-a3D-EVs led to significantly enhanced wound healing and anti-inflammatory capacities. Moreover, submucosal layer injection of T-a3D-EVs in chronic IC/BPS animal model resulted in restoration of bladder function, superior anti-inflammatory activity, and recovery of damaged urothelium compared to MSCs. Interestingly, we detected increased TGF-ß1 level in T-a3D-EVs, which might be involved in the anti-inflammatory activity of these EVs. Taken together, we demonstrate the excellent immune-modulatory and regenerative abilities of T-a3D-EVs as observed by recovery from urothelial denudation and dysfunction, which could be a promising therapeutic strategy for IC/BPS.