β-Adrenergic Receptor Subtypes in the Urinary Tract

Identifying multi-target drugs for prostate cancer using machine learning-assisted transcriptomic analysis

Prostate cancer is a leading cause of cancer death in men, and the development of effective treatments is of great importance. This study explored to identify the candidate drugs for prostate cancer by transcriptomic data and CMap database analysis. After integrating the results of omics analysis, bisoprolol is confirmed as a promising drug. Moreover, cell experiment reveals its potential inhibitory effect on the proliferation of prostate cancer cells. Importantly, machine learning methods are employed to predict the targets of bisoprolol, and the dual-target ADRB3 and hERG are explored by dynamic simulation. The findings of this study demonstrate the potential of bisoprolol as a multi-target drug for prostate cancer treatment and the feasibility of using beta-adrenergic receptor inhibitors in prostate cancer treatment. In addition, the proposed research approach is promising for discovering potential drugs for cancer treatment by leveraging the concept of drug side effects leading to anticancer effects. Further research is necessary to investigate the pharmacological action, potential toxicity, and underlying mechanisms of bisoprolol in treating prostate cancer with ADRB3.Communicated by Ramaswamy H. Sarma.

Overview of current pharmacotherapeutic options in benign prostatic hyperplasia

INTRODUCTION

Benign prostatic hyperplasia (BPH) represents the histological entity of prostate cell proliferation, which inflicts a gradually increasing obstruction of the bladder outlet and is accompanied by a progressing manifestation of lower urinary tract symptoms (LUTS). BPH management algorithm includes conservative measures, pharmaceutical agents, and surgical procedures.

AREAS COVERED

A comprehensive literature review was performed using PubMed, Scopus, and Google Scholar databases to identify publications written in English, analyzing BPH pharmaceutical treatment. The search was conducted from January 2000 to January 2023. Six main drug classes can be administered, either as monotherapy or in combination. Furthermore, the authors provide current direction of research on future medications, which focuses on a more etiological interference to the BPH pathophysiological mechanism.

EXPERT OPINION

The available medications represent an effective first-line step of BPH/LUTS therapy. Currently, the administration of BPH medications is tailored to patient/disease characteristics and entails long-time adherence to therapy. The emergence of new surgical modalities, which combine significantly lower morbidity compared to standard procedures and more durable effects than the available medications, seems to challenge the current treatment algorithm. More direct comparisons and the increasing experience with these surgical modalities will delineate the switch points between various therapy levels along the BPH management sequence.

Adrenoceptors in the Lower Urinary Tract

Adrenoceptors importantly contribute to the physiological regulation of lower urinary tract (LUT) function and have become a target of several clinically successful treatments for major LUT diseases. In the bladder dome, β-adrenoceptor subtypes are found in multiple cell types and mediate relaxation of detrusor smooth muscle, perhaps partly indirectly by acting on afferent nerves and cells of the mucosa. β₃-adrenoceptor agonists such as mirabegron and vibegron are used to treat overactive bladder syndrome. In the bladder trigone and urethra, α₁-adrenoceptors cause contraction and thereby physiologically contribute to bladder outlet resistance. α₁-adrenoceptors in the prostate also cause contraction and pathophysiologically elevate bladder outlet resistance leading to voiding dysfunction in benign prostatic hyperplasia. α₁-adrenoceptor antagonist such as tamsulosin is widely used as a first-line option to treat LUT symptoms in men, but it remains unclear to which extent and how smooth muscle relaxation contributes to symptom relief.

Spasmolytic and Uroprotective Effects of Apigenin by Downregulation of TGF-β and iNOS Pathways and Upregulation of Antioxidant Mechanisms: In Vitro and In Silico Analysis

Apigenin is a phytochemical obtained from Chamomilla recutita. Its role in interstitial cystitis is not yet known. The present study is aimed at understanding the uroprotective and spasmolytic effects of apigenin in cyclophosphamide-induced interstitial cystitis. The uroprotective role of apigenin was analyzed by qRT-PCR, macroscopic analysis, Evans blue dye leakage, histological evaluation, and molecular docking. The spasmolytic response was measured by adding cumulative concentrations of apigenin to isolated bladder tissue pre-contracted with KCl (80 mM) and carbachol (10^-9-10^-4) on non-incubated and pre-incubated tissues with atropine, 4DAMP, methoctramine, glibenclamide, barium chloride, nifedipine, indomethacin, and propranolol. Apigenin inhibited pro-inflammatory cytokines (IL-6, TNF-α and TGF 1-β) and oxidant enzymes (iNOS) while increasing antioxidant enzymes (SOD, CAT, and GSH) in CYP-treated groups compared to the control. Apigenin restored normal tissue of the bladder by decreasing pain, edema, and hemorrhage. Molecular docking further confirmed the antioxidant and anti-inflammatory properties of apigenin. Apigenin produced relaxation against carbachol-mediated contractions, probably via blockade of M₃ receptors, K_ATP channels, L-type calcium channels, and prostaglandin inhibition. While the blockade of M₂ receptors, K_IR channels, and β-adrenergic receptors did not contribute to an apigenin-induced spasmolytic effect, apigenin presented as a possible spasmolytic and uroprotective agent with anti-inflammatory, antioxidant effects by attenuating TGF-β/iNOS-related tissue damage and bladder muscle overactivity. Thus, it is a potential agent likely to be used in treatment of interstitial cystitis.

Loss of resilience contributes to detrusor underactivity in advanced age

Volume hyposensitivity resulting from impaired sympathetic detrusor relaxation during bladder filling contributes to detrusor underactivity (DU) associated with aging. Detrusor tension regulation provides an adaptive sensory input of bladder volume to the brainstem and is challenged by physiological stressors superimposed upon biological aging. We recently showed that HCN channels have a stabilizing role in detrusor sympathetic relaxation. While mature mice maintain homeostasis in the face of stressors, old mice are not always capable. In old mice, there is a dichotomous phenotype, in which resilient mice adapt and maintain homeostasis, while non-resilient mice fail to maintain physiologic homeostasis. In this DU model, we used cystometry as a stressor to categorize mice as old-responders (old-R, develop a filling/voiding cycle) or old-non-responders (old-NR, fail to develop a filling/voiding cycle; fluctuating high pressures and continuous leaking), while also assessing functional and molecular differences. Lamotrigine (HCN activator)-induced bladder relaxation is diminished in old-NR mice following HCN-blockade. Relaxation responses to NS 1619 were reduced in old-NR mice, with the effect lost following HCN-blockade. However, RNA-sequencing revealed no differences in HCN gene expression and electrophysiology studies showed similar percentage of detrusor myocytes expressing HCN (I_h) current between old-R and old-NR mice. Our murine model of DU further defines a role for HCN, with failure of adaptive recalibration of HCN participation and intensity of HCN-mediated stabilization, while genomic studies show upregulated myofibroblast and fibrosis pathways and downregulated neurotransmitter-degradation pathways in old-NR mice. Thus, the DU phenotype is multifactorial and represents the accumulation of age-associated loss in homeostatic mechanisms.

Safety and efficacy of intravesical epinephrine instillation in patients with intractable lower urinary tract hematuria - A novel approach

OBJECTIVES

To treat intractable hematuria with intravesical instillation of epinephrine.

METHODS

Sixty patients were treated with intravesical instillation of epinephrine at Mackay Memorial Hospital. The control group was composed of 60 patients who were treated with standard-of-care cystoscopic electrocautery fulguration. Under general anesthesia, epinephrine-treated group were injected with 150 mL of diluted epinephrine (1:10,000) through cystoscopy, followed by bladder irrigation with 1:100,000-diluted epinephrine at the ward. Successful hemostasis was defined as hematuria resolution within 1 month post-treatment without additional invasive procedures.

RESULTS

In the 60 patients who underwent intravesical instillation of epinephrine, radiation cystitis was the most common etiology (65.0%). Fifty-two patients (86.7%) required no additional therapy within 1 month after one course of intravesical epinephrine instillation treatment compared with 28 patients (46.7%) in the electrocautery fulguration-control group (p < 0.001). We observed a significant decrease in both the median length of hospitalization (p = 0.049) and the need for additional invasive procedures (p < 0.001) in the epinephrine group. In addition, cardiopulmonary monitoring of mean blood pressure, mean heart rate, and mean respiratory rate demonstrated no significant differences after epinephrine treatment.

CONCLUSIONS

In this study, intravesical instillation of epinephrine was an innovative method of hemostasis for intractable lower urinary tract hematuria with a success rate of 86.7%, compared to 46.7% in the control group, and significantly reduced the number of additional procedures required and the length of hospitalization. It was well tolerated by all patients, and was a safe and effective treatment modality for intractable hematuria or bladder hemorrhage.

Mirabegron improves the irritative symptoms caused by BCG immunotherapy after transurethral resection of bladder tumors

BACKGROUND

This study aims to explore the efficacy and safety of mirabegron in treating irritative symptoms induced by intravesical immunotherapy with Bacillus Calmette-Guerin (BCG) after transurethral resection of bladder tumors (TURBT).

METHODS

A total of 160 patients subjected to TURBT was randomly divided into the mirabegron group and placebo group with 80 patients in each group. Then, the patients were administered 25 mg mirabegron or placebo daily, starting the first day after BCG infusion. The first BCG perfusion was conducted at least 2 weeks after TURBT. The 3-day bladder diaries were completed in all patients, 1 day before BCG perfusion, and on the 1st, 6th, and 13th days after the first BCG perfusion. Overactive bladder symptom scores were completed 1 day before BCG perfusion, and on the 6th and 13th days after the first BCG perfusion.

RESULTS

Symptom scores of bladder hyperactivity were significantly different between the two groups (p < 0.001). Also, the frequency of nocturia, pollakiuria, micturition urgency, urinary incontinence and was significantly lower in group 1 than that in group two (p < 0.05).

CONCLUSION

Our findings demonstrate that mirabegron is a valuable clinical drug for the management of irritative symptoms after TURBT with subsequent intravesical BCG perfusion.

Role of α- and β-adrenergic signaling in phenotypic targeting: significance in benign and malignant urologic disease

The urinary tract is highly innervated by autonomic nerves which are essential in urinary tract development, the production of growth factors, and the control of homeostasis. These neural signals may become dysregulated in several genitourinary (GU) disease states, both benign and malignant. Accordingly, the autonomic nervous system is a therapeutic target for several genitourinary pathologies including cancer, voiding dysfunction, and obstructing nephrolithiasis. Adrenergic receptors (adrenoceptors) are G-Protein coupled-receptors that are distributed throughout the body. The major function of α1-adrenoceptors is signaling smooth muscle contractions through GPCR and intracellular calcium influx. Pharmacologic intervention of α-and β-adrenoceptors is routinely and successfully implemented in the treatment of benign urologic illnesses, through the use of α-adrenoceptor antagonists. Furthermore, cell-based evidence recently established the antitumor effect of α1-adrenoceptor antagonists in prostate, bladder and renal tumors by reducing neovascularity and impairing growth within the tumor microenvironment via regulation of the phenotypic epithelial-mesenchymal transition (EMT). There has been a significant focus on repurposing the routinely used, Food and Drug Administration-approved α1-adrenoceptor antagonists to inhibit GU tumor growth and angiogenesis in patients with advanced prostate, bladder, and renal cancer. In this review we discuss the current evidence on (a) the signaling events of the autonomic nervous system mediated by its cognate α- and β-adrenoceptors in regulating the phenotypic landscape (EMT) of genitourinary organs; and (b) the therapeutic significance of targeting this signaling pathway in benign and malignant urologic disease. Video abstract.

Detrusor Overactivity May Be a Prognostic Factor for Better Response to Combination Therapy Over Monotherapy in Male Patients With Benign Prostatic Enlargement and Storage Lower Urinary Tract Symptoms

Purpose

Several trials have shown that in men with overactive bladder (OAB) and benign prostate enlargement (BPE), the combination of an α-blocker with an anticholinergic is superior to α-blocker monotherapy. The purpose of this study is to explore whether urodynamic detrusor overactivity (DO) affects clinical outcomes in men with BPE and OAB.

Methods

This is a post hoc analysis of a prospective, randomized trial, designed to evaluate the changes of morphometric parameters of the prostate following monotherapy or combination therapy in men with BPE-OAB. The initial study recruited men aged ≥50 years, with BPE and predominantly storage lower urinary tract symptoms (LUTS). Patients were randomized to receive tamsulosin monotherapy or a combination of tamsulosin and solifenacin for 26 weeks. All participants completed a 3-day bladder diary and the International Prostate Symptom Score (IPSS), and then underwent pressure-flow and ultrasonographic studies. Data were stratified and analysed based on the urodynamic observation of DO at baseline (DO vs. non-DO). The primary endpoint was the mean change in urgency episodes from baseline. Secondary outcomes were the changes in nocturia, total IPSS, and urodynamic parameters.

Results

Sixty-nine men were initially randomized, but only 60 men were included in this analysis. Urgency episodes significantly improved in men with DO who received combination therapy compared to the DO monotherapy subgroup (P=0.04) or to the non-DO combination treatment subgroup (P=0.038). Nocturia also improved in the DO combination treatment subgroup as compared to the non-DO combination subgroup (P=0.037). The 24-hour frequency and total IPSS significantly improved from baseline without significant differences among the subgroups.

Conclusions

The present study suggests that baseline DO could be a prognostic factor for a better response to combination therapy over monotherapy in men with BPE and storage LUTS.

Mirabegron in the Treatment of Overactive Bladder: Safety and Efficacy in the Very Elderly Patient

Lower urinary tract symptoms, including urgency, urgency incontinence, frequency, and nocturia, are highly prevalent in older adults and are associated with significant morbidity and impairment in quality of life. When conservative measures such as bladder training fail to improve symptoms, pharmacological management is recommended by national and international guidelines. Mirabegron, an agonist of the β3 adrenergic receptor, demonstrates similar efficacy to the anticholinergic drugs without the risk of anticholinergic effects, but experience and evidence in the very elderly population are limited. This narrative review examines the current evidence base for mirabegron in very elderly adults.

β-Adrenoceptors regulate matrix metalloproteinase expression in human urothelial cells under hydrostatic pressure

The bladder wall is constantly subjected to intravesical pressure during the filling and voiding cycles. An imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) under elevated intravesical pressure contributes to pathological changes in the bladder. To investigate the changes in human urothelial cells (HUCs) under elevated intravesical pressure, this study analyzed the effect of β-adrenoceptor signaling on the expression of MMPs and TIMPs in HUCs exposed to pathological hydrostatic pressure (HP) (70 cm H₂ O) for 6 hours. Quantitative polymerase chain reaction, Western blot analysis, and cell fluorescence staining were used to explore the effect of β-adrenoceptor signaling on the expression of MMPs and TIMPs in HUCs after agonist and/or antagonist treatment. The expression levels of β₂ - and β₃ -adrenoceptor, MMP1, and MMP2 were greatly downregulated, while the expression of TIMP1 was greatly upregulated. Formoterol and BRL 37344, which are agonists of β₂ - and β₃ -adrenoceptor, respectively, significantly increased MMP1 and MMP2 expression under 70 cm H₂ O. As a classic downstream pathway of β₂ - and β₃ -adrenoceptor, protein kinase A (PKA) signaling inhibited MMP1 and MMP2 expression by regulating cAMP response element binding protein (CREB) activity. MMP1 and MMP2 expression in HUCs under 70 cm H₂ O was modified by β₂ - and β₃ -adrenoceptor via the PKA/CREB pathway. This outcome suggests that MMPs likely participate in the pathological effects of elevated intravesical pressure. The underlying mechanism of β₂ - and β₃ -adrenoceptor in elevated intravesical pressure was also revealed; this mechanism constitutes a new potential therapeutic target for partial bladder outlet obstruction.

Mirabegron causes vesical and urethral relaxation in rats with spinal cord injury

The effects of solifenacin and mirabegron on vesical and urethral function were compared in rats with or without spinal cord injury (SCI). Isovolumetric cystometry and urethral pressure recording were initially performed in intact rats. Then, the bladder neck was ligated under urethane anesthesia, after which a catheter was inserted through the bladder dome for isovolumetric cystometry and another catheter was inserted into the urethra to measure urethral pressure. Solifenacin (0.03-3 mg/kg) or mirabegron (0.03-3 mg/kg) was injected intravenously, and bladder and urethral activity were recorded. To create rats with SCI, the spinal cord was transected at the lower thoracic level under isoflurane anesthesia. After 2 weeks, a catheter was inserted through the bladder dome for single cystometry and bladder activity was recorded without anesthesia following intravenous injection of solifenacin or mirabegron. Isovolumetric cystometry revealed a larger decrease in maximum bladder contraction pressure after injection of solifenacin, whereas prolongation of the interval between bladder contractions was greater with mirabegron. In SCI rats, single cystometry showed that solifenacin and mirabegron both increased bladder volume at the first non-voiding bladder contraction and decreased the maximum bladder contraction pressure. Mirabegron also increased the voided volume and decreased the percentage residual volume without altering bladder capacity. Solifenacin and mirabegron both inhibited bladder contractility, and mirabegron possibly also induced urethral relaxation. Mirabegron may be suitable for patients with overactive bladder and residual urine.

The aging bladder insights from animal models

Alterations in bladder function with aging are very common and are very likely to represent an increasing healthcare problem in the years to come with the general aging of the population. In this review the authors describe the prevalence of lower urinary tract symptoms (LUTS) and comment upon potential mechanisms which may be responsible for the increasing prevalence of lower LUTS with increasing age, based on laboratory studies. It is clear that there is a complex interplay between the various components of the neural innervation structure of the bladder in leading to changes with age, which are likely to underpin the LUTS which are seen in the aging bladder.

Translational Research and Functional Changes in Voiding Function in Older Adults

Age-related LUT dysfunctions result from complex processes controlled by multiple genetic, epigenetic, and environmental factors and account for high costs of health care. This article discusses risk factors that may play a role in age-related LUT dysfunction and presents available data comparing structural and functional changes that occur with aging in the bladder of humans and animal models. A better understanding of factors and mechanisms underlying LUT symptoms in the older population may lead to therapeutic interventions to reduce these dysfunctions.

Increased Rho-kinase-mediated prostate contractions associated with impairment of β-adrenergic-cAMP-signaling pathway by chronic nitric oxide deficiency

Impairment of nitric oxide (NO) - cyclic GMP signaling pathway is likely to contribute to human begnin prostate hyperplasia (BPH). In the present study we have used a model of chronic NO synthesis inhibition to evaluate the functional alterations of prostate smooth muscle (PSM) machinery, and involvement of Rho-kinase pathway. Wistar rats were treated with the NO inhibitor N(ω)-nitro-l-arginine methyl ester (L-NAME, 20mg/kg/day; 4 weeks), after which contractile responses to phenylephrine (α1-adrenoceptor agonist; 1nM to 100µM), carbachol (muscarinic agonist; 1nM to 1mM) and α,β-methylene ATP (P2X receptor agonist; 1-10µM), as well as to electrical-field stimulation (EFS; 1-32Hz) were evaluated. PSM relaxations to isoproterenol (non-selective β-adrenoceptor agonist, 0.1nM to 10µM) and sodium nitroprusside (NO donor, 1nM to 10mM) were also evaluated. The ratio prostate weight/body weight was 22% greater (P<0.05) in L-NAME compared with control group. The PSM contractions to phenylephrine, carbachol and α,β-methylene ATP were higher in L-NAME (Emax: 3.85±0.25, 3.52±0.35 and 2.03±0.2mN, respectively) compared with control group (Emax: 3.08±0.17, 2.37±0.18 and 1.57±0.18mN, respectively). The PSM contractions induced by EFS were also significantly greater in L-NAME group. Prior incubation with the Rho-kinase inhibitor Y27632 (1µM) fully reversed the enhanced contractions to phenylephrine and carbachol. Isoproterenol-induced PSM relaxations were 34% lower in L-NAME group, which was associated with reduced levels of cAMP in prostate tissue. The relaxations to sodium nitroprusside remained unaltered in L-NAME group. In summary, chronic NO deficiency leads to increased Rho-kinase-mediated PSM contractile responses accompanied by impairment of β-adrenergic-cAMP-signaling pathway.

Do β-adrenoceptor agonists induce homologous or heterologous desensitization in rat urinary bladder?

β3-Adrenoceptor agonists have recently been introduced for the symptomatic treatment of the overactive bladder syndrome. As such treatment is not curative, long-term treatment is anticipated to be required. As the susceptibility of β3-adrenoceptors to undergo agonist-induced desensitization is cell type- and tissue-dependent, we have explored whether pre-treatment with a β-adrenoceptor agonist will attenuate subsequent relaxation responses to freshly added agonist using rat urinary bladder as a model. We have used the prototypical β-adrenoceptor agonist isoprenaline, the β2-selective fenoterol and the β3-selective CL 316,243 and mirabegron as well as the receptor-independent bladder relaxant forskolin. We show that a 6-h pre-treatment with agonist can significantly reduce subsequent relaxation against KCl-induced smooth muscle tone, but agonist-induced desensitization was also observed with longer pre-treatments or against passive tension. The agonist-induced desensitization was prominent for the β2 component of rat bladder relaxation but much weaker or even absent for the β3 component. Moreover, β-adrenoceptor agonist pre-treatment reduced contractile responses to the muscarinic agonist carbachol and the receptor-independent stimulus KCl. Taken together these data do not support the hypothesis that the long-term clinical efficacy of β3-adrenoceptor agonists in the treatment of the overactive bladder syndrome will be limited by receptor desensitization. Rather they raise the possibility that such treatment may not only cause smooth muscle relaxation but also may attenuate hyper-contractility of the bladder.

The cAMP effector EPAC activates Elk1 transcription factor in prostate smooth muscle, and is a minor regulator of α1-adrenergic contraction

Background

Prostate smooth muscle tone is regulated by α1-adrenoceptor-induced contraction and cAMP-mediated relaxation. EPAC is an effector of cAMP, being involved in smooth muscle relaxation and cell cycle control outside the lower urinary tract. Here, we investigated the expression and function of EPAC in human prostate tissues from patients undergoing radical prostatectomy.

Results

mRNA and protein expression of EPAC was detected in all prostate tissues by RT-PCR and Western blot analysis. Immunoreactivity was observed in stromal cells, and colocalized with immunofluorescence for α-smooth muscle actin and calponin. Under normal conditions, noradrenaline- or phenylephrine-induced contraction of prostate strips in the organ bath was not affected by the EPAC activator pCPT (SP-8-pCPT-2^′-O-Me-cAMPS.NA) (30 μM). However, when the cyclooxygenase inhibitor indomethacin (50 μM) was added, EPAC activators pCPT and OME (8-CPT-2^′-O-Me-cAMP.Na) (30 μM) significantly reduced contractions by low concentrations of phenylephrine. These effects were not observed on noradrenaline-induced contraction. OME and pCPT caused phosphorylation of the transcription factor Elk1 in prostate tissues. Elk1 activation was confirmed by EMSA (electrophoretic mobility shift assay), where OME and pCPT incresed Elk1 binding to a specific DNA probe.

Conclusions

EPAC activation may reduce α1-adrenergic prostate contraction in the human prostate, although this effect is masked by cyclooxygenases and β-adrenoceptors. A main EPAC function in the human prostate may be the regulation of the transcription factor Elk1.

A multicenter, double-blind, randomized, placebo-controlled trial of the β3-adrenoceptor agonist solabegron for overactive bladder

BACKGROUND

β-Adrenoceptor agonists are effective in animal models of bladder dysfunction, and the human bladder primarily expresses the β3 receptor subtype.

OBJECTIVE

To evaluate the efficacy and tolerability of the highly selective and potent β3-adrenoceptor agonist solabegron in a clinical proof-of-concept study in incontinent women with overactive bladder (OAB).

DESIGN, SETTING, AND PARTICIPANTS

This was a randomized, double-blind trial in adult women with OAB (one or more 24-h incontinence episodes and eight or more average 24-h micturitions).

INTERVENTIONS

Solabegron 50 mg (n=88), solabegron 125 mg (n=85), or placebo (n=85)-all twice daily-were administered.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary efficacy end point was percentage change from baseline to week 8 in the number of incontinence episodes over 24 h. Secondary end points included actual change and percentage change from baseline to week 4 and week 8 in micturitions per 24 h, urgency episodes per 24 h, and volume voided per micturition. Adverse events (AEs) were assessed, as well.

RESULTS AND LIMITATIONS

Solabegron 125 mg produced a statistically significant difference in percent change from baseline to week 8 in incontinence episodes over 24h when compared with placebo (p=0.025). Solabegron 125 mg treatment also showed statistically significant reductions from baseline to weeks 4 and 8 in micturitions over 24 h and a statistically significant increase from baseline to week 8 in urine volume voided. Solabegron was well tolerated, with a similar incidence of AEs in each treatment group. There were no significant treatment differences for mean changes from baseline to week 8 in systolic blood pressure (BP), diastolic BP, mean arterial pressure (MAP), or heart rate during the 24-h ambulatory measurement.

CONCLUSIONS

Solabegron significantly reduced the symptoms of OAB in women with moderate to severe OAB. Solabegron was safe, well tolerated, and did not demonstrate significant differences in AEs as compared to placebo. β3-Adrenoceptor agonists may represent a new therapeutic approach for treating OAB symptoms.