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Aims: Rodent cystometry has provided valuable insights into the impact of the disease, injury, and aging on the cellular and molecular pathways, neurologic processes, and biomechanics of lower urinary tract function. The purpose of this white paper is to highlight the benefits and shortcomings of different experimental methods and strategies and to provide guidance on the proper interpretation of results. Methods: Literature search, selection of articles, and conclusions based on discussions among a panel of workers in the field. Results: A range of cystometric tests and techniques used to explore biological phenomena relevant to the lower urinary tract are described, the advantages and disadvantages of various experimental conditions are discussed, and guidance on the practical aspects of experimental execution and proper interpretation of results are provided. Conclusions: Cystometric evaluation of rodents comprises an extensive collection of functional tests that can be performed under a variety of experimental conditions. Decisions regarding which approaches to choose should be determined by the specific questions to be addressed and implementation of the test should follow standardized procedures. (Less)

Aims Two phase 1 trials were performed in healthy women with the overactive bladder (OAB) syndrome and urodynamically demonstrated detrusor overactivity (DO), with the aim to demonstrate the safety and potential efficacy of URO‐902, which comprises a gene therapy plasmid vector expressing the human big potassium channel α subunit. Methods ION‐02 (intravesical instillation) and ION‐03 (direct injection) were double‐blind, placebo‐controlled, multicenter studies without overlap in enrollment between studies. Active doses were administered and evaluated sequentially (lowest dose first) for safety. ION‐02 participants received either 5000 µg or 10 000 µg URO‐902, or placebo. ION‐03 participants received either 16 000 or 24 000 µg URO‐902, or placebo, injected directly into the bladder wall using cystoscopy. Primary outcome variables were safety parameters occurring subsequent to URO‐902 administration; secondary efficacy variables also were evaluated. Results Among the safety outcomes, there were no dose‐limiting toxicities or significant adverse events (AEs) preventing dose escalation during either trial, and no participants withdrew due to AEs. For efficacy, in ION‐02 (N = 21), involuntary detrusor contractions on urodynamics at 24 weeks in patients receiving URO‐902 (P

Objective: To perform a descriptive microscopic study of prostatectomy specimens from 19 patients which anatomically characterizes the distributions of periprostatic nerve qualities, and to visualize these using diffusion tensor imaging (DTI). Materials and Methods: Serial whole-mounted sections were stained for cholinergic (neuronal nitric oxide synthase), adrenergic (tyrosine hydroxylase) and sensory (calcitonin gene-related peptide) nerves. Extracapsular stained nerves were counted by prostate surface sector, and classified by diameter. Stain-related relative density was calculated, and distribution patterns were evaluated. To better visualize the reported neuronal structures and independently confirm our findings, nerve concordance in five male volunteers was investigated using a 3-Tesla magnetic resonance imaging-DTI system. Results: At the base, cholinergic nerves were distributed from the anterolateral to posterior sectors, continuing posterolaterally (mid-section) into the posterolateral-posterior sector toward the apex. Adrenergic nerves were distributed across the anterolateral-posterior sectors at the base, with the course narrowing to the posterolateral-posterior sectors at the mid- and apical levels. Sensory fibres were found posterolaterally posteriorly at the base, continuing posterolaterally over the mid- and apical levels. Although it was not possible to determine the different nerve qualities, DTI confirmed histological findings from the base to the apex. Conclusions: Different types of nerve fibres were found to vary in distribution. When linked to possible functional aspects of the different nerve types, this morphological evidence may be of importance to further protect function after radical prostatectomy (RP). To our knowledge, this is the first time that DTI has confirmed reported histological findings in nerve-sparing RPs. DTI could be an important tool with which to correlate nerves to tumour for better preoperative planning and to incorporate imaging into treatment.

Aim: To discuss animal models of lower urinary tract disorders (LUTD) and their translational impact. Methods: Report of discussions based on presented literature-search based reviews relevant for the purpose. Results: Animal models can be used to investigate fundamental biological mechanisms, but also as tools to elucidate aspects of the pathogenesis of disease and to provide early evidence of any safety risk. Several different models may be required to obtain information that can have a translational impact. The term “translational research” covers not only the process of directly transferring knowledge from basic sciences to human trials to produce new drugs, devices, and treatment options for patients (T1 type translation) but also the implementation of early clinical research findings (phases I-III) into practice to improve care for patients (T2 type). Direct transfer of animal data to T2 is rarely possible, and the process often does not continue after the first trials in humans (phase I). It should be emphasized that many preclinical observations do not have (and do not need to have) immediate translational impact. Conclusions: No single animal model can mimic the complexity of the human disease. Still, animal models can be useful for gaining information on LUT function in humans, for elucidating pathophysiological mechanisms, and for the definition of targets for future drugs to treat LUT disorders. (Less)

Several studies indicate that pelvic ischemia and oxidative stress may play a significant role in lower urinary tract dysfunction (LUTD), including detrusor overactivity (DO)/overactive bladder (OAB) and detrusor underactivity (DU)/underactive bladder (UAB). The present article addresses proposal 1: "Are oxidative stress and ischemia significant causes of bladder damage leading to LUTD?" from the 2019 International Consultation on Incontinence-Research Society (ICI-RS) meeting. Bladder ischemia in animals and humans is briefly described, along with the proposed progression from ischemia to LUTD. Bladder ischemia is compared with ischemia of other organs, and the ongoing development of pelvic ischemia animal models is discussed. In addition, the distribution of blood within the bladder during filling and voiding and the challenges of quantification of blood flow in vivo are described. Furthermore, oxidative stress, including potential biomarkers and treatments, and challenges regarding antioxidant therapy for the treatment of LUTD are discussed. Finally, seven critical research questions and proposed studies to answer those questions were identified as priorities that would lead to major advances in the understanding and treatment of lower urinary tract symptoms (LUTS)/LUTD associated with pelvic ischemia and oxidative stress.

Objectives To examine the effect of intrathecal (i.t.) serotonin (5-hydroxytryptamine) 5-HT7 agonist administration on voiding function in the urethane-anesthetised rat, and the change in 5-HT7 receptor (5-HT7 R) expression in the lumbosacral cord Onuf's nucleus after spinal cord injury (SCI). Materials and methods In all, 32 female Sprague-Dawley (SD) rats were equally divided into a spinally intact (SI) group and SCI group (n = 16 each). At 8 weeks after transection, half of the rats underwent continuous cystometry under urethane anaesthesia, and the 5-HT7 R-selective agonist LP44 was given (i.t.). The remaining rats were used for pseudorabies (PRV) retrograde tracing, immunofluorescence, and Western Blot. Results LP44 administered i.t. had no effect in the SI rats. In SCI rats, LP44 (1-30 μg/kg) induced significant dose-dependent increases in micturition volume, voiding efficiency, number of high-frequency oscillations per micturition; and decreases in residual volume, bladder capacity, peak bladder pressure, threshold pressure and non-voiding contractions. The 5-HT7 R antagonist, SB-269970 (10 μg/kg), partially reversed LP44-induced changes. Using PRV retrograde tracing and immunofluorescence, 5-HT7 Rs were found in the L6-S1 spinal cord Onuf's nucleus in both SI and SCI rats, but the expression was significantly greater in the SCI rats. Western blot showed significantly more 5-HT7 Rs in the ventral L6-S1 spinal cord in SCI rats. Conclusion A 5-HT7 R agonist, given i.t., improved voiding efficiency in urethane-anesthetised SCI rats, and the 5-HT7 R was significantly up-regulated in the lumbosacral cord Onuf's nucleus. If valid for humans, these findings suggest that the 5-HT7 R could be a target for therapeutic interventions.

AIMS To explore whether autophagy plays a role in the remodeling of bladder smooth muscle cells (SMCs) in children with neurogenic lower urinary tract dysfunction (NLUTD), we investigated the effect of autophagy in NLUTD in the paediatric population. METHODS Bladder biopsies were taken from children with NLUTD and healthy donors as controls. Samples were labeled with the SMC markers calponin, smoothelin, and the autophagy proteins LC3, ATG5, and Beclin1. The contractile ability of bladder derived SMCs was investigated. RESULTS ATG5 gene and protein was upregulated in NLUTD muscle tissue compared to normal bladder. NLUTD muscle exhibited a punctated immunostaining pattern for LC3 in a subset of the SMCs, confirming the accumulation of autophagosomes. Pronounced elevation of ATG5 in the SMC in NLUTD tissue was associated with a downregulation of the key contractile proteins smoothelin and calponin. Pharmacological blocking of autophagy completely stopped the cells growth in normal bladder SMCs. Inhibition of autophagy in the NLUTD SMCs, with already elevated levels of ATG5, resulted in a reduction of ATG5 protein expression to the basal level found in normal controls. CONCLUSIONS Our study suggests that autophagy is an important factor affecting the remodeling of SMCs and the alteration of functionality in bladder smooth muscle tissue in the NLUTD. Since autophagy can be influenced by oral medication, this finding might lead to novel strategies preventing the deterioration of NLUTD muscle.

The acontractile bladder (AcB) is a urodynamic-based diagnosis wherein the bladder is unable to demonstrate any contraction during a pressure flow study. Although it is often grouped with underactive bladder, it is a unique phenomenon and should be investigated independently. The purpose of the present review was to examine the current literature on AcB regarding its pathology, diagnosis, current management guidelines, and future developments. We performed a review of the PubMed database, classifying the evidence for AcB pathology, diagnosis, treatment, and potential future treatments. Over the 67 years covered in our review period, 42 studies were identified that met our criteria. Studies were largely poor quality and mainly consisted of retrospective review or animal models. The underlying pathology of AcB is variable with both neurological and myogenic aetiologies. Treatment is largely tailored for renal preservation and reduction of infection. Although future developments may allow more functional restorative treatments, current treatments mainly focus on bladder drainage. AcB is a unique and understudied bladder phenomenon. Treatment is largely based on symptoms and presentation. While cellular therapy and neuromodulation may hold promise, further research is needed into the underlying neuro-urological pathophysiology of this disease so that we may better develop future treatments.

The discovery of the nitric oxide/cGMP pathway was the basis for our understanding of many normal physiological functions and the pathophysiology of several diseases. Since the discovery and introduction of sildenafil, inhibitors of PDE5 have been the first-line therapy for erectile dysfunction (ED). The success of sildenafil in the treatment of ED stimulated research in the field of PDE5 inhibition and led to many new applications, such as treatment of lower urinary symptoms, and pulmonary arterial hypertension, which are now approved indications. However, PDE5 inhibitors have also been used in several other disorders not discussed in this review, and the fields of clinical use are increasing. In the present review, the pharmacological basis of the NO/cGMP pathway and the rationale and clinical use of PDE5 inhibitors in different diseases are discussed.

Objectives To explore if the mechanism of the voiding dysfunction caused by spinal cord injury in rats can be improved by intravenous administration of the 5-HT2A/2C receptor agonist, DOI, and discuss whether it can be ascribed to serotonin 2A and 2C receptor up-regulation in lumbosacral cord motoneurons. Materials and Methods Female Sprague-Dawley rats were used, which were divided into two groups (Spinal cord injury group VS Normal control group). Under urethane anesthesia, cystometry was performed to examine the variation of urodynamic parameters before and after successive intrathecal administration of various doses of DOI into the lumbosacral cord. Additionally, the changes of serotonin 2A and 2C receptors in the lumbosacral cord were investigated by immunohistochemical staining and Western blot. Results Compared to controls, spinal cord injured rats had higher bladder capacity and post-void residual urine volume, and lower voiding efficiency. After spinal cord injury, DOI improved voiding efficiency likely via affecting external urethral sphincter activity. Immunohistochemical staining and Western blot analysis showed that serotonin 2A and 2C receptors were up-regulated in lumbosacral cord motoneurons. Conclusion In rats with spinal cord injury, DOI can improve voiding efficiency, and this may be due to serotonin 2A and 2C receptor up-regulation in lumbosacral cord motoneurons controlling external urethral sphincter activity. This article is protected by copyright. All rights reserved.

Half of the female population over age 50 years will experience pelvic organ prolapse. We suggest a new approach based on tissue engineering principles to functionally reconstruct the anatomical structures of the pelvic floor. The aim of this study is to investigate the mechanical performance and effect on collagen and elastin production of a degradable mesh releasing basic fibroblast growth factor (bFGF). Implantation of biodegradable mesh with or without bFGF in their core has been conducted in 40 rats in an abdominal wall defect model. Samples were explanted after 4, 8, and 24 weeks, and tested for mechanical properties and the composition of connective tissue. The study showed an increase in mRNA expression for collagen-I (p = 0.0060) and collagen-III (p = 0.0086) in the 4 weeks group with bFGF. The difference was equalized at 8 and 24 weeks. No difference was found at any time for protein amount for collagen-I, collagen-III, and fibronectin. The amount of collagen decreased from 4 to 24 weeks but the fraction of collagen increased. The maximal load of the newly formed tissue showed no effect of bFGF at any time. Exclusively, histology showed a limited ingrowth of collagen fibers after 4 weeks with bFGF but signs of elastin fibers were seen at 24 weeks. The investigation showed that a biodegradable mesh promotes tissue formation with a promising strength. The mesh with bFGF did not represent any advantage on either long or short term in comparison to the mesh without bFGF. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 680–688, 2018.

Aims The pathophysiologies of nocturia (NOC) and nocturnal polyuria (NP) are multifactorial and their etiologies remain unclear in a large number of patients. Clock genes exist in most cells and organs, and the products of Clock regulate circadian rhythms as representative clock genes. Clock genes regulate lower urinary tract function, and a newly suggested concept is that abnormalities in clock genes cause lower urinary tract symptoms. In the present study, we investigated the voiding behavior of Clock mutant (ClockΔ19/Δ19) mice in order to determine the effects of clock genes on NOC/NP. Methods Male C57BL/6 mice aged 8–12 weeks (WT) and male C57BL/6 ClockΔ19/Δ19 mice aged 8 weeks were used. They were bred under 12 hr light/dark conditions for 2 weeks and voiding behavior was investigated by measuring water intake volume, urine volume, urine volume/void, and voiding frequency in metabolic cages in the dark and light periods. Results No significant differences were observed in behavior patterns between ClockΔ19/Δ19 and WT mice. ClockΔ19/Δ19 mice showed greater voiding frequencies and urine volumes during the sleep phase than WT mice. The diurnal change in urine volume/void between the dark and light periods in WT mice was absent in ClockΔ19/Δ19 mice. Additionally, functional bladder capacity was significantly lower in ClockΔ19/Δ19 mice than in WT mice. Conclusions We demonstrated that ClockΔ19/Δ19 mice showed the phenotype of NOC/NP. The ClockΔ19/Δ19 mouse may be used as an animal model of NOC and NP. Neurourol. Urodynam. © 2016 Wiley Periodicals, Inc.

In the last decades, a number of new antimuscarinic drugs have been introduced for treatment of the overactive bladder (OAB), defined symptomatically (OAB syndrome) or urodynamically (detrusor overactivity). Recently, three new drug principles have been approved for clinical use, the β3 -adrenoceptor agonist, mirabegron, the phosphodiesterase-5 inhibitor, tadalafil and the blocker of afferent and efferent nerves, botulinum toxin. However, new alternatives are continuously being explored. OAB is a filling disorder, and ATP is involved in the generation of afferent impulses. One way of blocking the ATP afferent pathway is through the use of P2X3 receptor antagonists. In animal models, this strategy appears to work very well, but whether it translates effectively to man remains to be established. Evidence suggests that components of the endocannabinoid system are involved in regulation of bladder function. Clinical studies of cannabinoid extracts on LUTS are scarce and essentially restricted to patients with MS, and the results have so far not been convincing. Amplification of endocannabinoid activity by inhibiting their degradation via fatty acid amide hydrolase inhibitors may be an attractive approach, but no clinical experiences in OAB have been reported. Studies of the lower urinary tract have indicated that several transient receptor potential (TRP) channels, including TRPV1, TRPV2, TRPV4, TRPM8 and TRPA1, are expressed in the bladder and may act as sensors of stretch and/or chemical irritation. Animal studies have shown that inhibition of these pathways can be effective for the reduction in bladder activity. However, the roles of these channels for normal function and in pathological states have not been established, and so far adverse effects (hyperthermia) have hampered development of antagonists.

Background and purpose T16A(inh)-A01, CaCC(inh)-A01 and MONNA are identified as selective inhibitors of the TMEM16A calcium-activated chloride channel (CaCC). The aim of this study was to examine the chloride-specificity of these compounds on isolated resistance arteries in the presence and absence (±) of extracellular chloride. Experimental approach Isolated resistance arteries were maintained in a myograph and tension recorded, in some instances combined with microelectrode impalement for membrane potential measurements or intracellular calcium monitoring using fura-2. Voltage-dependent calcium currents (VDCC) were measured in A7r5 cells with voltage-clamp electrophysiology using barium as a charge carrier. Key results Rodent arteries preconstricted with noradrenaline or U46619 were concentration-dependently relaxed by T16A(inh) -A01 (0.1-10 μM): IC50 and maximum relaxation were equivalent in ±chloride (30 min aspartate substitution) and the T16A(inh) -A01-induced vasorelaxation ±chloride were accompanied by membrane hyperpolarization and lowering of intracellular calcium. However, agonist concentration-response curves ±chloride, with 10 μM T16A(inh) -A01 present, achieved similar maximum constrictions although agonist-sensitivity decreased. Contractions induced by elevated extracellular potassium were concentration-dependently relaxed by T16A(inh)-A01 ±chloride. Moreover, T16A(inh) -A01 inhibited VDCCs in A7r5 cells in a concentration-dependent manner. CaCC(inh) -A01 and MONNA (0.1-10 μM) induced vasorelaxation ±chloride and both compounds lowered maximum contractility. MONNA, 10 μM, induced substantial membrane hyperpolarization under resting conditions. Conclusions and implications T16A(inh) -A01, CaCC(inh) -A01 and MONNA concentration-dependently relax rodent resistance arteries, but an equivalent vasorelaxation occurs when the transmembrane chloride gradient is abolished with an impermeant anion. These compounds therefore display poor selectivity for TMEM16A and inhibition of CaCC in vascular tissue in the concentration range that inhibits the isolated conductance.

Objectives To examine the effects of the serotonin (5-HT)2A/2C receptor agonist (2,5-dimethoxy-4-idophenyl)-2-aminopropane hydrochloride (DOI) on micturition in rats with diabetes mellitus (DM). Methods Female Sprague–Dawley rats (n = 16) were divided into two groups: rats with Type 1 DM and age-matched control rats. DM was induced by i.p. injection of streptozotocin (65 mg/kg) and detailed cystometrogram (CMG) studies were performed 8 weeks post-injection in all rats under urethane anaesthesia. The selective 5-HT2A antagonist ketanserin was administered after each DOI dose–response curve was plotted. All drugs were administered i.v. Results Compared with controls, comprehensive urodynamic studies showed that DM rats had a higher bladder capacity and post-void residual urine volume (PVR), and a markedly lower voiding efficiency. In DM rats, DOI (0.01–0.3 mg/kg) induced significant dose-dependent increases in micturition volume and reductions in PVR, resulting in greater voiding efficiency. CMG measurements showed a dose-dependent increase in high-frequency oscillation (HFO) activity, evidenced by an increased duration of HFOs per voiding. This correlated with the improved voiding efficiency. Ketanserin (0.1 mg/kg) partially or completely reversed the DOI-induced changes. Conclusions The HFOs observed in the present study seem to correlate with external urethral sphincter bursting activity during voiding. Bladder voiding efficiency was reduced in DM rats. The 5-HT2A receptor agonist can enhance HFO activity and improves voiding efficiency, and so may represent a new strategy to improve voiding efficiency after DM in experimental studies.

The incidence of lower urinary tract symptoms, including overactive bladder (OAB), is continuing to rise, and is associated with a negative impact on quality of life and a heavy economic burden. A major risk factor for OAB is advancing age. The etiology of OAB is multifactorial and appears to involve myogenic, neurogenic, and urotheliogenic factors. In this article, we review the strengthening preclinical evidence supporting the contribution of chronic pelvic ischemia to the pathogenesis of OAB. In animal models, chronic ischemia induced by arterial injury and a high-fat diet upregulates markers of oxidative stress and proinflammatory cytokines in the urothelium and lamina propria, and leads to increased expression of nerve growth factor. These processes result in increased afferent activity and an increased frequency of micturition, reflecting a state of bladder hyperactivity. In severe, prolonged cases, bladder overactivity may develop into underactivity. Antimuscarinic therapies are the mainstay of OAB treatment, but their usefulness is limited by modest efficacy and troublesome side-effects. Our increasing understanding of the contribution of chronic ischemia to OAB is leading toward novel therapeutic options targeting chronic pelvic ischemia and its morphological, functional, and oxidative consequences. Preclinical trials have demonstrated encouraging results with α1 -adrenoreceptor blockade, phosphodiesterase type 5 inhibition, β3 -adrenoreceptor agonism, free radical scavenging, and stem cell therapy, in preventing morphological, biochemical and functional changes induced by chronic bladder ischemia.

Chronic bladder ischemia is potentially a common cause of lower urinary tract symptoms in the elderly. Epidemiological studies have shown a close association between lower urinary tract symptoms and vascular risk factors for atherosclerosis, and investigations using transrectal color Doppler ultrasonography have shown a negative correlation between decreased lower urinary tract perfusion and International Prostate Symptom Score in elderly patients with lower urinary tract symptoms. Bladder blood flow is also known to decrease in men with bladder outlet obstruction as a result of benign prostatic hyperplasia. Studies in animal models suggest that chronic bladder ischemia and repeated ischemia/reperfusion during a micturition cycle might produce oxidative stress, leading to denervation of the bladder and the expression of tissue-damaging molecules in the bladder wall, which could be responsible for the development of bladder hyperactivity progressing to bladder underactivity. The effects of drugs with different mechanisms of action; for example, α1-adrenoceptor antagonists, phosphodiesterase type 5 inhibitors, free radical scavengers and β3-adrenoceptor agonist, have been studied in animal models of chronic bladder ischemia. The drugs, representing different treatment principles for increasing blood flow and decreasing oxidative stress, showed protective effects not only on urodynamic parameters, but also on negative effects on muscle contractility and on detrimental structural bladder wall changes. Improvement of lower urinary tract perfusion and control of oxidative stress can be considered new therapeutic strategies for treatment of bladder dysfunction induced by chronic ischemia.

BACKGROUND The etiology of Benign Prostatic Hyperplasia (BPH), a common among aged men, is not fully understood, however, in addition to androgens and aging, chronic ischemia has been proposed to contribute. Using an established rat model, we investigated whether chronic ischemia alters the structural and functional properties of the ventral rat prostate, and whether phosphodiesterase type 5 (PDE5) inhibitor (tadalafil) may have a protective action. METHODS Adult male Sprague-Dawley rats were divided into control, arterial endothelial injury (AI), and AI with tadalafil treatment (AI-tadalafil) groups. AI and AI-tadalafil groups underwent endothelial injury of the iliac arteries and received a 2% cholesterol diet following AI. AI-tadalafil rats were treated with tadalafil (2 mg/kg/day) orally for 8 weeks after AI. The control group received a regular diet. After 8 weeks, animals were sacrificed, and pharmacological and morphological studies on prostate tissues were performed. RESULTS Iliac arteries from AI rats displayed neo-intimal formation and luminal occlusion, an effect that was not prevented by tadalafil treatment. In the AI group, there was an obvious epithelial atrophy and a statistically significant increase in collagen fibers compared with the controls. Immunohistochemically, there was an up-regulation of smooth muscle α-actin (SMA). Contractile responses of prostate strips to KCl, electrical field stimulation (EFS), and phenylephrine (PE) were significantly higher after AI than in controls. Chronic treatment with tadalafil prevented the increase in contractile responses in ischemic tissue, and decreased the collagen deposition compared with the AI group. CONCLUSIONS In this rat model, chronic pelvic ischemia caused distinct functional and morphological changes in the prostate. Prostatic tissue from ischemic animals showed an increased contractile response to electrical and pharmacological stimulation, an increase in SMA, and an increased deposition of collagen. All these changes could be prevented by treatment with the PDE5 inhibitor, tadalafil, suggesting an involvement of cyclic guanosine monophosphate (cGMP). Prostate 75:233–241, 2015. © 2014 The Authors. The Prostate Published by Wiley Periodicals, Inc.

Aims To assess the urodynamic effects of soluble guanylyl cyclase (sGC) stimulator, BAY 41-2272, and activator, BAY 60-2770, (which both are able to induce cGMP synthesis even in the absence of nitric oxide (NO)) alone or in combination with a phosphodiesterase type 5 (PDE5) inhibitor, vardenafil, in a model of partial urethral obstruction (PUO) induced bladder overactivity (BO). Methods Fifty-six male Sprague–Dawley rats were used, 31 of them underwent PUO. Fourteen rats were used for Western blots to assess PDE5 and sGC expression. For drug evaluation cystometry without anesthesia was performed three days following bladder catheterization. Results Obstructed rats showed higher micturition frequency and bladder pressures than non-obstructed animals (Intermicturition Interval, IMI, 2.28 ± 0.55 vs. 3.60 ± 0.60 min (± standard deviation, SD); maximum micturition pressure, MMP, 70.1 ± 8.0 vs. 48.8 ± 7.2 cmH2O; both P

There is abundant evidence that the lower urinary tract (LUT) mucosal layer is involved both in mechanosensory functions that regulate bladder contractile activity and in urethral sensation. Changes to the mucosa can be associated with a number of bladder pathologies. For example, alterations of the urothelium and underlying lamina propria at both the molecular and structural levels have been reported in both patients and animals associated with disorders such as bladder pain syndrome and diabetic cystopathy. In contrast to the urinary bladder, much less is known about the urothelium/lamina propria of the bladder neck/proximal urethra. There are important gender differences in the outflow region both anatomically and with respect to innervation, hormonal sensitivity, and location of the external urethral sphincter. There is reasonable evidence to support the view that the mucosal signaling pathway in the proximal urethra is important for normal voiding, but it has also been speculated that the proximal urethra can initiate bladder overactivity. When dysfunctional, the proximal urethra may be an interesting target, for example, botulinum toxin injections aiming at eliminating both urgency and incontinence due to detrusor overactivity.

Nocturia, awaking from sleep to void, has a negative impact on health and well-being. Nocturia affects men and women and is more prevalent among the elderly. More than two nocturnal voids is considered to be a clinically meaningful threshold associated with significant negative outcomes for health and well-being, and the timing of awakening has a significant bearing on the negative consequences of nocturia. Several serious underlying pathophysiologic conditions may be associated with nocturia. A thorough history and assessment of number and times of voids, void volume, and fluid intake is essential for determining the etiology of a patient's nocturia. With data obtained from the frequency-volume chart (FVC), which is used to collect quantitative voiding data, a patient's nocturia may be classified as global polyuria, nocturnal polyuria, reduced bladder capacity, or a combination of these categories. Global polyuria is defined as 24-hr urinary output that exceeds 40 ml/kg body weight and results in increased 24-hr urinary frequency. Nocturnal polyuria is defined as more than 20% of daily urine output at night in young patients and more than 33% in elderly patients. Reduced bladder capacity may be a result of idiopathic or neurogenic detrusor overactivity, bladder outlet obstruction, or reduced nocturnal bladder capacity. The pathophysiology underlying the findings of the FVC falls into five main categories: global polyuria, nocturnal polyuria, reduced bladder capacity, sleep disorders, and circadian clock disorders. This review discusses the epidemiology, etiology, and pathophysiology of nocturia.

Objective To evaluate bladder function in an established cannabinoid type 1 (CB1) receptor knockout (KO) mouse model via organ-bath (in vitro) and urodynamic (cystometric; in vivo) experiments. Materials and Methods In all, 20 8-week-old female wildtype (WT) mice (C57BL/6) and 20 age-matched CB1 KO mice were used. Six mice from each group were used for the organ-bath experiments, where the contractile responses of bladder tissue strips after carbachol exposure (carbachol concentration response curve [CCRC]; myogenic contraction) and during electrical field stimulation (EFS; neurogenic contraction) were assessed. In all, 14 mice per group were used for cystometric experiments without any anaesthesia, in which standard urodynamic variables were assessed 3 days after bladder catheterisation. Results The CCRCs of bladder strips from CB1 KO mice were similar to those of WT mice. However, during EFS the bladder strips from the CB1 KO mice had significantly lower contractile responses than WT preparations, indicating that in CB1 KO mice the neuronal component of bladder contraction was different. In cystometric experiments the CB1 KO mice had a higher micturition frequency (shorter mean [sem] inter-micturition interval of 3.24 [0.29] vs 7.32 [0.5] min), a lower bladder capacity (0.09 [0.01] vs 0.18 [0.01] mL) and micturition volume (0.07 [0.01] vs 0.14 [0.01] mL), a lower bladder compliance (0.007 [0.001] vs 0.02 [0.002] mL/cmH2O), and higher spontaneous bladder activity (5.1 [0.5] vs 2.6 [0.6] cmH2O) than WT mice (all P < 0.05, Student's t-test). In WT mice, systemic administration of rimonabant (SR141716), a CB1 receptor antagonist, resulted in urodynamic changes similar to those seen in the CB1 KO mice. Conclusions In vitro, bladder strips from CB1 KO mice responded to muscarinic receptor stimulation similarly as the WT controls, but were less responsive to electrical stimulation of nerves. In vivo, CB1 KO mice had a higher micturition frequency and more spontaneous activity than WT mice. The present findings suggest that CB1 receptors are involved in peripheral and central nervous control of micturition.

The pathophysiology of lower urinary tract symptoms (LUTS), particularly in the elderly, seems to be multifactorial. One of the factors involved may be chronic ischemia of the bladder caused by bladder outflow obstruction (male) or atherosclerosis (male/female). The mechanisms by which chronic ischemia initiates and causes LUTS and progressive bladder dysfunction, and the time course of the effects, are incompletely known. Bladder ischemia and repeated ischemia/reperfusion during a micturition cycle may produce oxidative stress, leading to denervation of the bladder and the expression of tissue damaging molecules in the bladder wall. This may be responsible for the development of detrusor overactivity progressing to detrusor underactivity and inability to empty the bladder. The extent of bladder dysfunction in chronic bladder ischemia may depend on the degree and duration of ischemia. To prevent chronic bladder ischemia caused by atherosclerosis and to treat its consequences, more pathophysiological knowledge is needed. Several animal models of atherosclerosis-induced chronic bladder ischemia are available and should be useful tools for further research.

Aims To better understand the effects of the selective 5-HT7 receptor agonist 4-[2-(Methylthio)phenyl]-N-(1,2,3,4-tetrahydro-1-naphthalenyl)-1-piperazinehexanamide hydrochloride (LP44) on micturition in spinal cord injury (SCI) rats. Methods Female Sprague-Dawley rats weighing 200–275 g were used. SCI was produced in 8 of the 16 rats by transection at the T10 level; cystometric study occurred 8–12 weeks post-transection. Intravesical pressure was monitored in urethane-anesthetized animals via a transvesical catheter. The selective 5-HT7 antagonist (R)-3-[2-[2-(4-Methylpiperidin-1-yl)ethyl]pyrrolidine-1-sulfonyl] phenol hydrochloride (SB-269970) was administered after each LP44 dose–response curve (all drugs were administered intravenously, i.v). Results Compared to controls, SCI rats had a higher bladder capacity and residual volume, and a lower voiding efficiency. In SCI rats, LP44 (0.003–0.3 mg/kg, i.v) induced significant dose-dependent increases in micturition volume, significant dose-dependent decreases in residual volume, resulting in significant increases in voiding efficiency. CMG measurements showed a dose-dependent increase of the high-frequency oscillation (HFO) activity, including the number of small oscillation per voiding. This was correlated with the improved voiding efficiency. SB-269970 (0.1 mg/kg, i.v) partially or completely reversed all LP44-induced changes. Conclusions HFOs seems to be correlated with external urethral sphincter (EUS) bursting activity during voiding. Both the bladder voiding efficiency and the periodic EUS activity were decreased in SCI rats. 5-HT7 receptor agonist can enhance HFO activity, thereby improving voiding efficiency. Whether or not these results may have implications for the future treatment of voiding dysfunction in SCI patients remains to be studied. Neurourol. Urodynam. 33:1165–1170, 2014. © 2013 Wiley Periodicals, Inc.

The bladder mucosa consists of the urothelium, basement membrane, and lamina propria (LP). Although the urothelium has been given much attention, it may be regarded as one part of a signaling system involving another equally important component of the bladder mucosa, namely, the LP. The LP lies between the basement membrane of the mucosa and the detrusor muscle and is composed of an extracellular matrix containing several types of cells, including fibroblasts, adipocytes, interstitial cells, and afferent and efferent nerve endings. In addition, the LP contains a rich vascular network, lymphatic vessels, elastic fibers, and smooth muscle fascicles (muscularis mucosae). The roles of the LP and its components in bladder function have not been definitively established, though it has been suggested to be the capacitance layer of the bladder, determining bladder compliance and enabling adaptive changes to increasing volumes. However, the bladder LP may also serve as a communication center, with an important integrative role in signal transduction to the central nervous system (nociception, mechanosensation). The LP may also, by means of its different components, make it possible for the urothelium to transmit information to other components of the bladder wall, contributing to activation of the detrusor muscle. In addition, the LP may serve as a source for production of factors influencing the growth of both the overlying urothelium and the underlying detrusor muscle.

Aims The contribution of individual CB receptors (CB1R and CB2R) to normal micturition has not been clearly defined. Our goal was to study if differences in urodynamic parameters or in vitro bladder contractility can be demonstrated between CB2R knockout (CB2RKO) and C57BL/6J control (wild type, WT) mice. Methods Female WT and CB2RKO mice underwent bladder catheterization and cystometry was performed after 2 and 3 days. Cystometric evaluations were performed in awake animals without drug administration, and WT were also given HU-308 (CB2R agonist) followed by AM630 (CB2R antagonist). Bladders were removed for in vitro assessment of contractile responses to carbachol and electrical field stimulation (EFS). Results CB2RKO mice had significantly higher intercontraction intervals (ICIs), bladder capacity (BC) and compliance (Bcom) than WT controls (P

Aims To describe the morphological and functional consequences for bladder development and function when nicotinamide mononucleotide adenylyltransferase 2 (Nmnat2) is lacking or reduced. Methods The Bloated Bladder (Blad) mouse, lacking Nmnat2, and heterozygotes were utilized for this investigation. Morphology and development of the bladder were studied using immunohistochemistry against urothelial, smooth muscle, and nerve markers. Functional effects were assessed by organ bath experiments and cystometry. Results Homozygote mutants were malformed and died at birth, whereas heterozygotes survived and morphologically did not differ from wild-type controls. Morphological bladder changes appeared in the Blad mutants as early as embryonic day 15.5 (E15.5) with an extremely distended bladder at E18.5. Staining revealed that all the bladder layers were present and expressed mature markers in all three genotypes. No nerves could be demonstrated by immunohistochemistry in the Blad mutant bladder at E18.5. Organ bath analysis showed that bladders from Blad mutant showed signs of denervation supersensitivity in response to carbachol, and no response to electrical stimulation of nerves at E18.5. Adult heterozygotes, which have a reduced expression of Nmnat2 at E18.5, showed decreased responses to carbachol and electrical stimulation compared to wild-type controls. The latter also retained their ability to empty their bladders, but showed increased micturition pressures compared to controls. Conclusions Complete loss of Nmnat2 leads to a mature but distended bladder in utero and is not compatible with survival. Moderate loss of Nmnat2 has no effect on bladder development, survival, and has only modest effects on bladder function later in life. Neurourol. Urodynam. 32:1130–1136, 2013. © 2013 Wiley Periodicals, Inc.

What's known on the subject? and What does the study add? There are many studies showing melatonin's potent endogenous free radical scavenging and antioxidative properties, which protect against oxidative insult, but there is no information about the effect of chronic treatment with melatonin on oxidative-stress-related bladder dysfunction caused by chronic ischaemia. The model used in this study shows that functional and morphological changes caused by chronic bladder ischaemia and oxidative stress were protected by chronic treatment with melatonin, resulting in improvement of bladder hyperactivity. Objective To investigate the potential therapeutic benefit of melatonin for chronic ischaemia-related bladder dysfunction. Materials and Methods Adult male Sprague–Dawley rats were divided into control, arterial injury (AI), AI with low-dose melatonin treatment (AI-ML) and AI with high-dose melatonin treatment (AI-MH) groups. The AI, AI-ML and AI-MH groups underwent a procedure to induce endothelial injury of the iliac arteries and received a 2% cholesterol diet after AI. The rats in the AI-ML and AI-MH groups were treated with melatonin 2.5 or 20 mg/kg/day orally for 8 weeks after AI. The control group received a regular diet. After 8 weeks, urodynamic investigations were performed. Bladder tissues and iliac arteries were processed for pharmacological studies, and for immunohistochemical and histological examination. Results Iliac arteries from AI, AI-ML and AI-MH rats displayed neo-intimal formation and luminal occlusion. In the AI group, the micturition interval was significantly shorter, and bladder capacity and voided volume were lower than in the controls. Contractile responses of bladder strips to KCl, electrical field stimulation and carbachol were significantly lower after AI than in the controls. The AI bladders were found to have a significantly increased collagen ratio, oxidative stress and inducible nitric oxide synthase (NOS) expression, and decreased constitutive NOS expression compared with the controls. In the AI-ML and AI-MH groups, neo-intimal formation was not prevented, but there were beneficial effects on bladder function and morphology. In the AI-ML group, the beneficial effects failed to reach statistical significance. In the AI-MH group, melatonin significantly improved oxidative stress and NOS expression, and there were significant improvements in all the functional and morphological variables compared with the AI group. Conclusions Arterial occlusive disease may lead to chronic bladder ischaemia and bladder hyperactivity associated with oxidative stress. In the model used, chronic treatment with melatonin protected bladder function and morphology, probably through its free radical scavenging and antioxidative properties. Melatonin may prevent oxidative damage and improve ischaemia-related bladder dysfunction.

Historically, α(1)-adrenoceptors have been classified into three subtypes (α(1)(A), α(1)(B) and α(1)(D)) that are widely distributed in various organs. Research on the α(1)(D)-adrenoceptors in the bladder, urethra and prostate has focused on the relationship between expression levels and symptoms of bladder outlet obstruction, and the implications and functional roles of α(1)(D)-adrenoceptors subtypes in these organs. The α(1)(D)-adrenoceptor messenger ribonucleic acid and protein seem to be increased in obstructed bladders or small capacity bladders. In contrast, α(1)(D)-adrenoceptor subtype knock-out mice have been found to have a prolonged voiding interval. Interestingly, an α(1)(D)-adrenoceptor antagonist was found to inhibit the facilitation of afferent nerve activity for the micturition reflex induced by intravesical infusion of acetic acid. Clinically, patients who felt urgency at low filling volumes and had a small bladder capacity were found to have more α(1)(D)-adrenoceptor messenger ribonucleic acid in their bladder mucosa than patients who felt urgency at high filling volumes and had a large bladder capacity. An α(1)(D)-adrenoceptor antagonist was found to increase the first desired volume and the maximum desired volume while decreasing detrusor overactivity in pressure flow studies. Thus, α(1)(D)-adrenoceptors in the lower urinary tract might play an important role in the pathophysiology of lower urinary tract disorders.

The overactive bladder syndrome and detrusor overactivity are conditions that can have major effects on quality of life and social functioning. Antimuscarinic drugs are still first-line treatment. These drugs often have good initial response rates, but adverse effects and decreasing efficacy cause long-term compliance problems, and alternatives are needed. The recognition of the functional contribution of the urothelium/suburothelium, the autonomous detrusor muscle activity during bladder filling and the diversity of nerve transmitters involved has sparked interest in both peripheral and central modulation of overactive bladder syndrome/detrusor overactivity pathophysiology. Three drugs recently approved for treatment of overactive bladder syndrome/detrusor overactivity (mirabegron, tadalafil and onabotulinum toxin A), representing different pharmacological mechanisms; that is, β-adrenoceptor agonism, phosphodiesterase type 5 inhibition, and inhibition of nerve release of efferent and afferent transmitters, all seem to have one effect in common: inhibition of the afferent nervous activity generated by the bladder during filling. In the present review, the different mechanisms forming the pharmacological basis for the use of these drugs are discussed.

Aims We determined if transient receptor potential melastatin 8 (TRPM8) channels are involved in the detrusor overactivity induced by menthol, or exposure to low temperature (LT). Methods Two days prior to cystometric investigation, the bladders of 10-week-old Sprague–Dawley rats were cannulated to measure bladder pressure. After a 20 min baseline cystometry period, the TRPM8 channel antagonist, N-(4-tert-butylphenyl)-4-(3-chloropyridin-2-yl)piperazine-1-carboxamide (BCTC), or vehicle, was administered through a jugular vein catheter (n = 6). A 90% menthol solution was sprayed onto bare leg skin once every 5 min for 20 min, and then cystometric measurements were repeated. After a 30-min recovery period, the rats were intravenously administered 0.1 µmol/kg BCTC. Five minutes later, they were again sprayed and cystometry recorded. In separate experiments, cannulated rats were intravenously administered 0.001, 0.01, or 0.1 µmol/kg BCTC (n = 6 each dose). Five minutes later, they were exposed to LT (4 ± 2°C) for 20 min of cystometry. Results Menthol spray decreased voiding interval, micturition volume, and bladder capacity in the BCTC-free rats. However after BCTC administration, these effects were prevented. Exposure to LT elicited detrusor overactivity that caused decreased voiding interval, micturition volume, and bladder capacity. However, at 0.01 and 0.1 µmol/kg, BCTC inhibited this cold stress-induced detrusor overactivity. Conclusions Since the TRPM8 channel agonist, BCTC, inhibited detrusor overactivity in rats sprayed with the TRPM8 channel agonist, menthol, and the drug also inhibited cold stress-induced detrusor overactivity, we conclude that TRPM8 channels mediate, at least partially, detrusor overactivity elicited by exposure to LT. Neurourol. Urodynam. 32: 500–504, 2013. © 2012 Wiley Periodicals, Inc.

BACKGROUND AND PURPOSE α(1) -Adrenoceptor-induced contraction of prostate smooth muscle is mediated by calcium- and Rho kinase-dependent mechanisms. In addition, other mechanisms, such as activation of c-jun N-terminal kinase (JNK) may be involved. Here, we investigated whether JNK participates in α(1)-adrenoceptor-induced contraction of human prostate smooth muscle. EXPERIMENTAL APPROACH Prostate tissue was obtained from patients undergoing radical prostatectomy. Effects of the JNK inhibitors SP600125 (50 µM) and BI-78D3 (30 µM) on contractions induced by phenylephrine, noradrenaline and electric field stimulation (EFS) were studied in myographic measurements. JNK activation by noradrenaline (30 µM) and phenylephrine (10 µM), and the effects of JNK inhibitors of c-Jun phosphorylation were assessed by Western blot analyses with phospho-specific antibodies. Expression of JNK was studied by immunohistochemistry and fluorescence double staining. KEY RESULTS The JNK inhibitors SP600125 and BI-78D3 reduced phenylephrine- and noradrenaline-induced contractions of human prostate strips. In addition, SP600125 reduced EFS-induced contraction of prostate strips. Stimulation of prostate tissue with noradrenaline or phenylephrine in vitro resulted in activation of JNK. Incubation of prostate tissue with SP600125 or BI-78D3 reduced the phosphorylation state of c-Jun. Immunohistochemical staining demonstrated the expression of JNK in smooth muscle cells of human prostate tissue. Fluorescence staining showed that α(1A)-adrenoceptors and JNK are expressed in the same cells. CONCLUSIONS AND IMPLICATIONS Activation of JNK is involved in α(1)-adrenoceptor-induced prostate smooth muscle contraction. Models of α(1)-adrenoceptor-mediated prostate smooth muscle contraction should include this JNK-dependent mechanism.

Aims To investigate the relationship between urinary bladder mucosal expression of β3-adrenoceptor (AR) mRNA and urodynamic findings in patients with lower urinary tract symptoms and benign prostatic obstruction (BPO). Methods During surgical prostate resection of 32 BPO patients, mucosal biopsies were collected and analyzed by reverse transcriptase polymerase chain reaction to determine the expression level of β3-AR mRNA. First desire to void (FDV) and strong desire to void (SDV), detrusor overactivity (DO), and bladder outlet obstruction (BOO) were measured pre-operatively. Patients with FDVs 201 ml and SDVs > 301 ml were assigned to the large capacity group (n = 13). The same patients with positive DO were also assigned to the DO+ group (n = 11), and those with negative DO were assigned to the DO− group (n = 21). Finally, patients whose position on the Schafer nomogram was greater than degree V were assigned to the severe BOO group (n = 17), while those with less than degree IV were assigned to the mild BOO group (n = 15). Results The expression level of β3-AR mRNA was similar in both bladder capacity groups and both DO groups. However, the expression level in the severe BOO group was significantly less than in the mild BOO group (P = 0.043). Conclusions The expression of bladder mucosal β3-AR mRNA was significantly decreased in patients with severe BOO, suggesting that β3-ARs might be affected by the degree of BOO. Neurourol. Urodynam. 32: 88–91, 2013. © 2012 Wiley Periodicals, Inc.

Normal functioning of the urinary bladder and the distal gut is an essential part of daily physiological activity coordinated by the peripheral and central nervous systems. Pathological changes in one of these organs may induce the development of cross-organ sensitization in the pelvis and underlie clinical co-morbidity of genitourinary and GI dysfunctions. Experimental human and animal data suggest that the bladder and distal colon interact under both normal and pathological conditions, however, the directions of these interactions can change dramatically depending on the nature and duration of the applied stimuli. This review article aimed to summarize the clinical data on colon-bladder cross-reflexes in healthy individuals, as well as in patients with co-morbid disorders. It also discusses currently used animal models, experimental approaches, and suggested mechanisms of colon-bladder cross-talk. Additionally, it provides an overview of the potential pharmacological targets to develop treatment options for patients with co-morbid disorders. Presented work resulted from the discussion of colon/bladder interactions during “Think Tank 9” presentations at the International Consultation on Incontinence Research Society meeting held in Bristol, UK, 2011.

Background Botulinum neurotoxins type A (BoNT/A), β3-adrenergic receptor agonists, and phosphodiesterase type 5 (PDE5) inhibitors are promising agents that mitigate lower urinary tract symptoms by attenuating the sensory system. However, whether they act directly on afferent nerves or indirectly through the other cell types is unclear. Methods Spinal cord transected female mice were used as a model for neurogenic bladder overactivity. In vivo methods utilized decerebrate mouse cystometry. In vitro approaches included optical mapping of Ca2+ transient, single unit afferent nerve recordings and tension measurements from bladder sheets and wall cross-sections. Immunohistochemistry was used to measure the expression of β3-adrenergic receptors on dorsal root ganglion (DRG) neurons. Results Our unique approaches revealed the direct effects of BoNT/A in inhibiting neuropeptide release and firing rates in afferents following bladder injections. β3-adrenergic receptor agonists are demonstrated to directly inhibit afferent nerve firing independent of the relaxing effects on bladder smooth muscle. Moreover, data suggest the expression of these receptors on DRG neurons that send projections to the bladder. The mechanism of action of PDE5 inhibitors on bladder overactivity is discussed. Discussion The questions raised during the plenary session of the 2011 International Consultation on Incontinence-Research Society meeting regarding the benefits of BoNT/A, β3-adrenergic receptor agonist and PDE5 inhibitor treatments of overactive bladder are addressed. Conclusion Our findings suggest that the abovementioned agents, in low enough concentrations, can directly inhibit afferent excitability without decreasing detrusor contractility. Accordingly, they have considerable potential for treating the sensory component of lower urinary tract dysfunctions. Neurourol. Urodynam. 31:300–308, 2012. © 2012 Wiley Periodicals, Inc.

Aims To develop a rat model of atherosclerosis-induced chronic bladder ischemia and investigate the effect of chronic bladder ischemia on voiding behavior and bladder function. Methods Adult male rats were divided into three groups. The arterial injury (AI) group underwent endothelial injury of the iliac arteries and received a 2% cholesterol diet. The sham group underwent sham operation and received a 2% cholesterol diet. The control group received a regular diet. After 8 weeks, a metabolic cage study and cystometry were performed without anesthesia. Bladder blood flow was measured using a laser Doppler blood flowmeter. Histological examination of the iliac arteries and the bladder was performed. The bladder was also processed for immunohistochemical staining of oxidative stress markers. Results The metabolic cage study showed that in the AI group, voiding frequency significantly increased while voided volume significantly decreased. Cystometry showed that the frequency of reflex bladder contractions was significantly higher in the AI group. Filling-induced decrease in bladder blood flow was the greatest in the AI group. Histological study showed that in the AI group alone, atherosclerotic occlusion occurred in the iliac arteries as well as in the downstream bladder microvessels. Oxidative stress marker positive cells were more prevalent in the AI bladder than in the other bladders. Conclusions Combined with a high-cholesterol diet, endothelial injury of iliac arteries induced arterial occlusive disease in the downstream vessels and consequent bladder ischemia in rats. This model of chronic bladder ischemia showed detrusor overactivity manifested as an increase in voiding frequency. Neurourol. Urodynam. 31:195–200, 2012. © 2011 Wiley Periodicals, Inc.

Pelvic floor disorders (PFDs) such as stress urinary incontinence (SUI) and pelvic organ prolapse (POP) may share a common pathophysiological process related to pelvic floor tissue laxity and loss of support. We reviewed recent literature on observed biochemical changes in women with SUI and POP, linking them to genetic predisposition. We found that studies of pelvic tissues showed differences between control subjects and women with POP and SUI in collagen and elastin structure at a molecular and fibrillar level. Studies were heterogeneous but showed a trend towards decreased collagen and elastin content. The contribution of matrix metalloproteinases to increased collagenolysis can be related to genetic polymorphisms present in higher frequency in women with PFD. Extracellular matrix (ECM) protein turnover plays a role in the development of POP and SUI, but much remains to be understood of this complex dynamic interplay of enzymes, proteins and molecules. Genotyping of candidate genes participating in ECM formation will elucidate the missing link between the manifestation of the disease and the biochemical changes observed systematically, in addition to those in the pelvic floor.

Aims Serotonin affects micturition in the normal rat through actions not only on ascending and descending spinal pathways and supraspinal centers but also on the lumbosacral spinal cord level. The selective 5-HT1A receptor agonist, 8-OH-DPAT((R)-(+)-8-hydroxy-2-(di-n-propylamino) tetralin), reversed detrusor-sphincter dyssynergia (DSD) in the spinal cord injury (SCI) rat. Rats with experimental diabetes mellitus (DM) have been shown to have both bladder and urethral dysfunction during reflex voiding. We therefore examined the effects of 8-OH-DPAT on micturition in DM rats. Methods Female Sprague–Dawley rats were used. DM was induced by an intraperitoneal injection of streptozotocin (STZ, 65 mg/kg) and a cystometric study was performed 8 weeks post-injection. External urethral sphincter electromyography (EUS-EMG) was also measured. The 5-HT1A antagonist WAY-100635(N-tert-butyl-3-(4-(2-methoxyphenyl)-piperazin-1-yl)-2-phenylpropanamide) was administered after each 8-OH-DPAT dose–response. Results Compared to controls, DM rats had a higher bladder capacity, residual volume, and a lower voiding efficiency. In DM rats, 8-OH-DPAT (3–1,000 µg/kg, i.v.) induced significant dose-dependent increases in micturition volume, and decreases in residual volume, resulting in increases in voiding efficiency. During the micturition, there was a dose-dependent increased phasic EUS activity correlated with the improved voiding efficiency. WAY-100635 (300 µg/kg, i.v.) reversed the 8-OH-DPAT-induced changes. Conclusions Both the bladder voiding efficiency and the periodic EUS activity were decreased in DM rats. 5-HT1A receptor agonism promoted periodic EUS activity, thereby improving voiding efficiency. Whether or not these results may have implications for the future treatment of voiding dysfunction in DM patients remains to be studied. Neurourol. Urodynam. 31:168–173, 2012. © 2011 Wiley Periodicals, Inc.

Study Type – Therapy (individual cohort) Level of Evidence 2b What's known on the subject? and What does the study add? It has been documented that currently used anti-muscarinics can cause adverse effects on the CNS. This study adds knowledge that the OAB population has more CNS disorders that make them vulnerable to the potential CNS effects of OAB anti-muscarinics. OBJECTIVE • To determine the proportion of patients with overactive bladder (OAB) potentially at risk for adverse events by assessing their pre-existing central nervous system (CNS), cardiovascular (CV) and other co-morbidities. PATIENTS AND METHODS • The GE Centricity Electronic Medical Record database was utilized to identify patients with a diagnosis of OAB using International Classification of Diseases, Ninth Revision (ICD-9) codes or a prescription between 1 January 1996 and 30 March 2007 for an OAB anti-muscarinic agent. • Matched non-OAB patients were assigned the same index date as the corresponding OAB patient. Based on the presence of ≥ one pharmacy claim for an OAB anti-muscarinic agent, the OAB cohort was stratified as treated or untreated. A random sample of age- and gender-matched patients formed a non-OAB control cohort. • An additional and separate analysis focusing on all co-morbidities was performed examining non-OAB patients who were matched to OAB patients on 1:1 propensity score matching, based on age, body mass index (BMI) and gender at baseline. • Charlson Comorbidity Index (CCI), using ICD-9 codes, and the Chronic Disease Score (CDS), using prescribed drugs, were calculated. RESULTS • When compared with non-OAB patients (N= 77 272; 83.2% women; median age 64 years), OAB patients (N= 41 440; 83.6% women; median age 65 years) had more overall CNS co-morbidities (45.4 vs 29.0%; P < 0.001). • In addition, OAB patients had a higher use of medications with anti-muscarinic effects (39.6 vs 25.4%; P < 0.001). OAB patients were also more likely to have CV co-morbidities (57.6 vs 44.6%; P < 0.001). • CNS co-morbidities were slightly more common in untreated (n= 8 106) than in treated (n= 33 334) OAB patients (47.2 vs 45.0%; P < 0.001). CV co-morbidities were higher in treated OAB patients (58.8 vs 53.7%; P < 0.001). • In the additional separate analysis, which focused on all co-morbidities, patients with OAB had higher mean CCI and CDS scores than patients without OAB (CCI: 1.17 vs 1.11 [P < 0.001]; CDS: 2.95 vs 1.74 [P < 0.001]). • After controlling for other covariates, the linear regressions (n= 22 544) showed that OAB patients had higher CCI and CDS than patients without OAB. CONCLUSIONS • Among OAB patients, CNS, CV and all co-morbidities were more prevalent than in non-OAB patients. • Prior exposure to CNS medications was more prevalent in OAB patients who received anti-muscarinic treatment than in those who did not. • Co-morbidities and concomitant medications affecting the CNS and the CV system should be taken into account when making the decision on the most appropriate OAB treatment option for each individual patient.

Antimuscarinic agents are the main drugs used to treat patients with the overactive bladder (OAB) syndrome, defined as urgency, with or without urgency incontinence, usually with increased daytime frequency and nocturia. Since the treatment is not curative and since OAB is a chronic disease, treatment may be life-long. Antimuscarinics are generally considered to be ‘safe’ drugs, but among the more serious concerns related to their use is the risk of cardiac adverse effects, particularly increases in heart rate (HR) and QT prolongation and induction of polymorphic ventricular tachycardia (torsade de pointes). An elevated resting HR has been linked to overall increased morbidity and mortality, particularly in patients with cardiovascular diseases. QT prolongation and its consequences are not related to blockade of muscarinic receptors, but rather linked to inhibition of the hERG potassium channel in the heart. However, experience with terodiline, an antimuscarinic drug causing torsade de pointes in patients, has placed the whole drug class under scrutiny. The potential of the different antimuscarinic agents to increase HR and/or prolong the QT time has not been extensively explored for all agents in clinical use. Differences between drugs cannot be excluded, but risk assessments based on available evidence are not possible.

Background: Bombesin (BOM) and gastrin releasing peptide (GRP) have been located to the lower urinary tract (LUT). However, there is a paucity of data demonstrating the impact of these endogenous peptides. Objectives: The aim of the present study was to investigate the contractile actions of BOM and GRP on the female rat urethra in vitro and in vivo. Female Sprague-Dawley rats (n = 37) weighing approximately 225 g were used. Intraurethral pressure was recorded by a catheter placed at the maximum pressure zone corresponding to the intrinsic urethral sphincter. Measurements: In vitro, changes in intraurethral pressure was conducted on perfused intact urethral/bladder preparations and are expressed as percentages of sphincteric intraurethral pressure achieved with noradrenaline. In vivo, changes in intraurethral pressure was conducted in anesthetized subjects and compared with the baseline intraurethral pressure and sham controls. Results: In vitro, the increase in intraurethral pressure induced by BOM was 23.6 +/- 3.2 cmH(2)O, exceeding the pressure evoked with NA by 9.6 cmH(2)O or 174.4% whereas GRP induced a maximum pressure of 10.7 +/- 1.6 cmH(2)O, an increase of 2.2 +/- 0.5 cmH(2)O or 82.9% (P < 0.05) of the NA evoked pressure. In vivo, the mean baseline pressure was 22.9 +/- 1.4 cmH(2)O. The intraurethral pressure evoked by BOM was 50.6 +/- 6.3 cmH(2)O (P < 0.05), and for GRP, the evoked intraurethral pressure was 56.2 +/- 13.4 cmH(2)O (P < 0.05). Conclusions: The present data suggest that both BOM and GRP may contribute to the control of continence by their contractile action on the sphincters of the LUT outflow region. Neurourol. Urodynam. 30:1388-1391, 2011. (C) 2011 Wiley-Liss, Inc. (Less)

Background The PDE5 inhibitor tadalafil is investigation for the treatment of lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH). Several clinical studies of tadalafil and other PDE5 inhibitors have reported significant symptom reduction but limited urinary flow rate improvement. This manuscript reviews the published literature describing the pathophysiology of male LUTS, with an emphasis on mechanisms that may be modulated or improved by phosphodiesterase type 5 (PDE5) inhibition. Methods Literature (through March 2010) was obtained via Medline searches and from the individual reviewers files. Articles were selected for review based on describing in vitro, preclinical, or clinical studies of pathological processes contributing to LUTS, or possible effects of PDE5 inhibition in the lower urinary tract. Results Major mechanisms contributing to LUTS include: reduced nitric oxide/cyclic guanosine monophosphate signaling; increased RhoA kinase pathway activity; autonomic overactivity; increased bladder afferent activity; and pelvic ischemia. Tadalafil and other PDE5 inhibitors have demonstrated beneficial effects on smooth muscle relaxation, smooth muscle and endothelial cell proliferation, nerve activity, and tissue perfusion that may impact LUTS in men. Conclusions The pathophysiology of male LUTS is complex and not completely understood. LUTS may occur independently of BPH or secondary to BPH but in both cases involve obstructive or irritative mechanisms with substantial pathophysiological overlap. While the precise mechanism remains unclear, inhibition of PDE5 seems to have an effect on several pathways that may impact LUTS. Neurourol. Urodynam. 30:292–301, 2011. © 2011 Wiley-Liss, Inc.

A substantial portion of the current research on lower urinary tract dysfunction is focused on afferent mechanisms. The main goals are to define and modulate the signaling pathways by which afferent information is generated, enhanced and conveyed to the central nervous system. Alterations in bladder afferent mechanisms are a potential source of voiding dysfunction and an emerging source for drug targets. Established drug therapies such as muscarinic receptor antagonists, and two emerging therapies, beta(3)-adrenergic receptor agonists and botulinum toxin type-A, may act partly through afferent mechanisms. This review focuses on these two new principles and new and established methods for determining their sites of action. It also provides brief information on the innervation of the bladder, afferent receptors and transmitters and how these may communicate with the urothelium, interstitial cells and detrusor smooth muscle to regulate micturition. Peripheral and central mechanisms of afferent sensitization and myogenic mechanisms that lead to detrusor overactivity, overactive bladder symptoms and urgency sensations are also covered. This work is the result from 'Think Tank' presentations, and the lengthy discussions that followed, at the 2010 International Consultation on Incontinence Research Society meeting in Bristol, UK. Neurourol. Urodynam. 30:684-691, 2011.

Aims Previous studies have suggested that ATP has a role in mechano-afferent transduction, at least partly mediated by nerves other than capsaicin (Cap)-sensitive nerves. We investigated the direct effect of ATP on single fiber activity (SFA) of the primary bladder afferent nerves and its relationship with Cap-sensitivity. Methods Female Sprague–Dawley rats were used. On the basis of conduction velocities, SFA was grouped as Aδ- or C-fibers. First, SFA and intravesical pressure were measured during filling as the baseline. Then, Cap (10−5 M) was instilled intravesically and the SFA response was monitored. To desensitize Cap-sensitive nerves, resiniferatoxin (RTX) (10−6 M) was administered intravesically, and then Cap was again administered to confirm the desensitization effect. Thereafter, ATP (10−3 M) or its vehicle was instilled intravesically and another filling cycles recorded. Results Thirty-two single afferent fibers were discriminated. Aδ-fibers did not respond to intravesical instillation of Cap, RTX or ATP. Based on Cap-sensitivity, C-fibers could be divided into two subtypes: Cap-sensitive (n = 8) and Cap-insensitive (n = 16). In the Cap-sensitive C-fibers, the response to bladder filling mostly disappeared after RTX desensitization, no matter if the bladder was filled with vehicle or ATP. On the other hand, in the Cap-insensitive C-fibers, even after RTX-treatment, the response was preserved and more enhanced when the bladder was filled with ATP compared to vehicle. Conclusions Mechanosensitive bladder afferents can be classified as (1) Aδ-fibers, (2) Cap-insensitive, and (3) Cap-sensitive C-fibers. The activation of the bladder afferents induced by intravesical application of ATP is mediated mainly through Cap-insensitive C-fibers. Neurourol. Urodyn. 30:163–168, 2011. © 2010 Wiley-Liss, Inc.

center dot The transient receptor potential (TRP) channel superfamily has been shown to be involved in nociception and mechanosensory transduction in various organ systems, and studies of the LUT have indicated that several TRP channels, including TRPV1, TRPV2, TRPV4, TRPM8, and TRPA1, are expressed in the bladder, and may act as sensors of stretch and/or chemical irritation. center dot However, the roles of these individual channels for normal LUT function and in LUTS/DO/OAB, have not been established. center dot TRPV1 is the channel best investigated. It is widely distributed in LUT structures, but despite extensive information on morphology and function in animal models, the role of this channel in normal human bladder function is still controversial. Conversely, its role in the pathophysiology and treatment of particularly neurogenic DO is well established. center dot TRPV1 is co-expressed with TRPA1, and TRPA1 is known to be present on capsaicin-sensitive primary sensory neurones. Activation of this channel can induce DO in animal models. center dot TRPV4 is a Ca2+-permeable stretch-activated cation channel, involved in stretch-induced ATP release, and TRPV4-deficient mice exhibit abnormal frequencies of voiding and non-voiding contractions in cystometric experiments. center dot TRPM8 is a cool receptor expressed in the urothelium and suburothelial sensory fibres. It has been implicated in the bladder-cooling reflex and in idiopathic DO. center dot The occurrence of other members of the TRP superfamily in the LUT has been reported, but information on their effects on LUT functions is scarce. There seem to be several links between activation of different members of the TRP superfamily and LUTS/DO/OAB, and further exploration of the involvement of these channels in LUT function, normally and in dysfunction, may be rewarding.

What’s known on the subject? and What does the study add? The effects of oestrogen on lower urinary tract structure and function, and on the autonomic nervous control of the region, have been examined in animal studies, often with conflicting results. To determine if a decrease in oestrogen levels increases activity in bladder afferent nerves, we investigated the effects of oestrogen loss on afferent nerve activity in rats subjected to ovariectomy. Comparisons were made with findings in ageing female rats. In conclusion, this study suggests that oestrogen deficiency caused by ovariectomy does not increase bladder afferent nerve activity in the rat. Even if it may affect storage function in the rat, it seems unlikely that oestrogen deficiency per se is the main driver of the increase in afferent activity and voiding frequency that is observed in ageing female rats. It has also been suggested that, although the prevalence of urinary incontinence increases with age, the increase may not be related directly to oestrogen deficiency in the postmenopausal female. OBJECTIVE • To determine if a decrease in oestrogen (E) levels increases activity in bladder afferent nerves, by investigating the effects of E loss on afferent nerve activity in ovariectomized (OVX) rats, and making comparisons with findings in ageing female rats. MATERIALS AND METHODS • Female Sprague-Dawley rats were divided into four groups: ageing; OVX+ E; OVX+ vehicle (V); and sham-operated (SHAM) + V. • The E (250 µg/kg) or V (cottonseed oil) was injected s.c. once a week for 8 weeks. • Frequency–volume recordings were performed with the rats in metabolic cages, and single Aδ- or C-fibre activities from the bladder were measured. • After measurements, the blood serum was collected and the estradiol (E2) level was measured. RESULTS • The C-fibre activity of OVX + V rats was significantly lower than in the other groups. • Aδ-fibre activity was unchanged. • Despite low E2 levels, ageing rats showed high afferent activity and voiding frequency. CONCLUSION • Although a low E level may affect storage function, it is unlikely that it is the main cause of the high afferent activity and voiding frequency observed in the ageing female rat.

OBJECTIVE To study the role of α2-adrenoceptors (α2-AR) in micturition of anaesthetized male rats, with specific focus on the effects on the electrical activity (by electromyography, EMG) of the rhabdosphincter, and actual urinary flow rate, as the effects mediated by α2-ARs on sphincter activity and urethral pressures have not been established. MATERIALS AND METHODS Adult anaesthetized male Noble rats were used; intravesical pressure, rhabdosphincter EMG and urinary flow rate from the distal urethra were recorded. After baseline recordings, an α2-AR agonist (dexmedetomidine, DEX) or α2-AR antagonist (atipamezole), were injected intravenously. RESULTS DEX treatment significantly decreased the maximum bladder pressure and urinary flow rate, and the amplitude of rhabdosphincter EMG was significantly reduced. Intraluminal pressure high-frequency oscillations, usually observed during rat voiding were abolished. The effects of DEX were fully reversed within 31 min. Atipamezole treatment significantly increased actual urinary flow rates and rhabdosphincter EMG amplitude, but the number of times flow was interrupted was increased during the voiding cycle, leading to increased overall micturition time. CONCLUSION Stimulation and blockade of α2-ARs have a significant effect on lower urinary tract function. If the data from this rat model are also valid in humans, a study of the effects of atipamezole on urethral sphincter activity and urethral pressures in humans would be of interest, and might show therapeutic potential of the drug.