Alpha1-, alpha2- and beta-adrenoceptors in the urinary bladder, urethra and prostate

Effects of carvedilol on human prostate tissue contractility and stromal cell growth pointing to potential clinical implications

BACKGROUND

Apart from antagonizing ß-adrenoceptors, carvedilol antagonizes vascular α1-adrenoceptors and activates G protein-independent signaling. Even though it is a commonly used antihypertensive and α1-adrenoceptors are essential for the treatment of voiding symptoms in benign prostatic hyperplasia, its actions in the human prostate are still unknown. Here, we examined carvedilol effects on contractions of human prostate tissues, and on stromal cell growth.

METHODS

Contractions of prostate tissues from radical prostatectomy were induced by electric field stimulation (EFS) or α1-agonists. Growth-related functions were examined in cultured stromal cells.

RESULTS

Concentration-response curves for phenylephrine, methoxamine and noradrenaline were right shifted by carvedilol (0.1-10 µM), around half a magnitude with 100 nM, half to one magnitude with 1 µM, and two magnitudes with 10 µM. Right shifts were reflected by increased EC50 values for agonists, with unchanged Emax values. EFS-induced contractions were reduced by 21-54% with 0.01-1 µM carvedilol, and by 94% by 10 µM. Colony numbers of stromal cells were increased by 500 nM, but reduced by 1-10 µM carvedilol, while all concentrations reduced colony size. Decreases in viability were time-dependent with 0.1-0.3 µM, but complete with 10 µM. Proliferation was slightly increased by 0.1-0.5 µM, but reduced with 1-10 µM.

CONCLUSIONS

Carvedilol antagonizes α1-adrenoceptors in the human prostate, starting with concentrations in ranges of known plasma levels. In vitro, effect sizes resemble those of α1-blockers used for the treatment of voiding symptoms, which requires concentrations beyond plasma levels. Bidirectional and dynamic effects on the growth of stromal cells may be attributed to "biased agonism".

Pharmacotherapy in Stress Urinary Incontinence; A Literature Review

PURPOSE OF REVIEW

Stress urinary incontinence (SUI) is a commonly observed condition in females, as well as in males who have undergone prostatectomy. Despite the significant progress made in surgical techniques, pharmacotherapy has not yielded substantial outcomes within the clinical domain. This review aims to present a comprehensive overview of the existing pharmacotherapy options for stress urinary incontinence (SUI) and the emerging therapeutic targets in this field.

RECENT FINDINGS

One meta-analysis demonstrated that α-adrenergic medications are more efficacious in improving rather than curing SUI symptoms. One trial showed reduced pad weight gain with PSD-503, a locally administered α-adrenergic receptor agonist. New data show that duloxetine's risk outweighs its benefits. One small-scale trial was found to support the use of locally administered estriol in improving subjective outcomes. Emerging targets include serotonin 5HT2C agonists, selective inhibitors of norepinephrine uptake, and myostatin inhibitors. Only one of the evaluated drugs, duloxetine, has been approved by some countries. Currently, trials are evaluating novel targets. Systemic adverse effects such as gastrointestinal upset with duloxetine and orthostatic hypotension with α-adrenoceptor agonists have hampered the efficacy of drugs used to treat SUI in women and men.

Comparative efficacy of commercial oral poly-herbal traditional Chinese medicine formulations combined with western medicine in benign prostatic hyperplasia management: a systematic review and network meta-analysis

Background: Benign prostatic hyperplasia (BPH) is prevalent among the aging male population and often presents with distressing lower urinary tract symptoms. There is emerging evidence that commercial oral poly-herbal traditional Chinese medicine (TCM) formulation combined with Western medicine (WM) may offer enhanced therapeutic effects compared to WM alone in BPH treatment. Nevertheless, determining the optimal formulations for BPH remains controversial. We aimed to employ a network meta-analysis to compare and assess differences among commonly used and recommended poly-herbal TCM formulations outlined in the Chinese guidelines for BPH treatment, providing clinical medication recommendations and guidance. Methods: We extensively searched for RCTs of BPH patients that had oral poly-herbal TCM formulations and WM treatment, covering both English and Chinese databases up to 31 October 2023. The quality of the included studies was evaluated using the Cochrane risk-of-bias tool Version 2 (ROB2). A Bayesian network meta-analysis was performed to assess the effectiveness of various formulations, followed by sensitivity and subgroup analyses. Results: Our meta-analysis included 107 RCTs involving 11,037 patients across 16 oral poly-herbal TCM formulations. The quality of the selected studies was assessed as "Some concerns". Most formulations combined with WM demonstrated superior therapeutic efficacy compared to WM alone. For clinical effective rate, Jingui Shenqi pill (JGSQ) + WM had the highest-ranking probability (87.38%). Concerning International Prostate Symptom Score (IPSS) and maximum flow rate of urine, Guizhi Fuling capsule (GZFL) + WM was most effective (91.10% and 98.55%). Regarding the quality of life score and postvoid residual urine, Pulean tablet (PLA) + WM ranked first (86.71% and 91.81%). In controlling prostate volume, Huange capsule (HE) + WM demonstrated the highest efficacy (95.65%). Additionally, among the interventions, Lingze (LZ) + WM capsule exhibited the lowest incidence of adverse drug reactions (2.32%). Conclusion: Combining oral poly-herbal TCM formulations with WM may provide greater therapeutic benefits in BPH treatment compared to WM alone. JGSQ, GZFL, PLA, and HE emerged as promising treatment options. However, further rigorous empirical studies are essential to substantiate these findings. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=459651, CRD 42023459651.

Polygenic risk score predicting susceptibility and outcome of benign prostatic hyperplasia in the Han Chinese

BACKGROUND

Given the high prevalence of BPH among elderly men, pinpointing those at elevated risk can aid in early intervention and effective management. This study aimed to explore that polygenic risk score (PRS) is effective in predicting benign prostatic hyperplasia (BPH) incidence, prognosis and risk of operation in Han Chinese.

METHODS

A retrospective cohort study included 12,474 male participants (6,237 with BPH and 6,237 non-BPH controls) from the Taiwan Precision Medicine Initiative (TPMI). Genotyping was performed using the Affymetrix Genome-Wide TWB 2.0 SNP Array. PRS was calculated using PGS001865, comprising 1,712 single nucleotide polymorphisms. Logistic regression models assessed the association between PRS and BPH incidence, adjusting for age and prostate-specific antigen (PSA) levels. The study also examined the relationship between PSA, prostate volume, and response to 5-α-reductase inhibitor (5ARI) treatment, as well as the association between PRS and the risk of TURP.

RESULTS

Individuals in the highest PRS quartile (Q4) had a significantly higher risk of BPH compared to the lowest quartile (Q1) (OR = 1.51, 95% CI = 1.274-1.783, p < 0.0001), after adjusting for PSA level. The Q4 group exhibited larger prostate volumes and a smaller volume reduction after 5ARI treatment. The Q1 group had a lower cumulative TURP probability at 3, 5, and 10 years compared to the Q4 group. PRS Q4 was an independent risk factor for TURP.

CONCLUSIONS

In this Han Chinese cohort, higher PRS was associated with an increased susceptibility to BPH, larger prostate volumes, poorer response to 5ARI treatment, and a higher risk of TURP. Larger prospective studies with longer follow-up are warranted to further validate these findings.

Organ-specific off-target effects of Pim/ZIP kinase inhibitors suggest lack of contractile Pim kinase activity in prostate, bladder, and vascular smooth muscle

Smooth muscle contraction by Pim kinases and ZIPK has been suggested, but evidence for lower urinary tract organs or using Pim-selective inhibitor concentrations is not yet available. Here, we assessed effects of the Pim inhibitors AZD1208 and TCS PIM-1 and the dual ZIPK/Pim inhibitor HS38 on contractions of human prostate and bladder tissues and of porcine interlobar arteries. Human tissues were obtained from radical prostatectomy and radical cystectomy and renal interlobar arteries from pigs. Contractions were studied in an organ bath. Noradrenaline-, phenylephrine- and methoxamine-induced contractions were reduced (up to > 50%) with 500-nM AZD1208 in prostate tissues and to lesser degree and not consistently with all agonists in interlobar arteries. A total of 100-nM AZD1208 or 500-nM TCS PIM-1 did not affect agonist-induced contractions in prostate tissues. Decreases in agonist-induced contractions with 3-µM HS38 in prostate tissues and interlobar arteries were of small extent and did not occur with each agonist. Carbachol-induced contractions in detrusor tissues were unchanged with AZD1208 (500 nM) or HS38. Electric field stimulation-induced contractions were not affected with AZD1208 or HS38 in any tissue, but slightly reduced with 500-nM TCS PIM-1 in prostate tissues. Concentration-dependent effects of Pim inhibitors suggest lacking Pim-driven smooth muscle contraction in the prostate, bladder, and interlobar arteries but point to organ-specific functions of off-targets. Procontractile functions of ZIPK in the prostate and interlobar arteries may be limited and are lacking in the detrusor.

Inside the Biology of the β3-Adrenoceptor

Since the first discovery in 1989, the β3-adrenoceptor (β3-AR) has gained great attention because it showed the ability to regulate many physiologic and metabolic activities, such as thermogenesis and lipolysis in brown and white adipose tissue, respectively (BAT, WAT), negative inotropic effects in cardiomyocytes, and relaxation of the blood vessels and the urinary bladder. The β3-AR has been suggested as a potential target for cancer treatment, both in adult and pediatric tumors, since under hypoxia its upregulation in the tumor microenvironment (TME) regulates stromal cell differentiation, tumor growth and metastases, signifying that its agonism/antagonism could be useful for clinical benefits. Promising results in cancer research have proposed the β3-AR being targeted for the treatment of many conditions, with some drugs, at present, undergoing phase II and III clinical trials. In this review, we report the scientific journey followed by the research from the β3-Ars' discovery, with focus on the β3-Ars' role in cancer initiation and progression that elects it an intriguing target for novel antineoplastic approaches. The overview highlights the great potential of the β3-AR, both in physiologic and pathologic conditions, with the intention to display the possible benefits of β3-AR modulation in cancer reality.

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.

Non-pharmacological and drug treatment of autonomic dysfunction in multiple system atrophy: current status and future directions

Multiple system atrophy (MSA) is a sporadic, fatal, and rapidly progressive neurodegenerative disease of unknown etiology that is clinically characterized by autonomic failure, parkinsonism, cerebellar ataxia, and pyramidal signs in any combination. Early onset and extensive autonomic dysfunction, including cardiovascular dysfunction characterized by orthostatic hypotension (OH) and supine hypertension, urinary dysfunction characterized by overactive bladder and incomplete bladder emptying, sexual dysfunction characterized by sexual desire deficiency and erectile dysfunction, and gastrointestinal dysfunction characterized by delayed gastric emptying and constipation, are the main features of MSA. Autonomic dysfunction greatly reduces quality of life and increases mortality. Therefore, early diagnosis and intervention are urgently needed to benefit MSA patients. In this review, we aim to discuss the systematic treatment of autonomic dysfunction in MSA, and focus on the current methods, starting from non-pharmacological methods, such as patient education, psychotherapy, diet change, surgery, and neuromodulation, to various drug treatments targeting autonomic nerve and its projection fibers. In addition, we also draw attention to the interactions among various treatments, and introduce novel methods proposed in recent years, such as gene therapy, stem cell therapy, and neural prosthesis implantation. Furthermore, we elaborate on the specific targets and mechanisms of action of various drugs. We would like to call for large-scale research to determine the efficacy of these methods in the future. Finally, we point out that studies on the pathogenesis of MSA and pathophysiological mechanisms of various autonomic dysfunction would also contribute to the development of new promising treatments and concepts.

Treatment Algorithm for Management of Benign Prostatic Obstruction: An Overview of Current Techniques

The management of benign prostatic obstruction (BPO) should involve a treatment algorithm that takes into account prostate size, and patient's symptoms and preference with the aim of helping with urinary symptoms and enhance quality of life. The diagnostic assessment for men with lower urinary tract symptoms (LUTS) should be comprehensive to help choose the best management strategy. Strategies from lifestyle modifications to medical treatment with alpha blockers and/or 5-alpha-reductase inhibitors to surgical procedures can all be used in the management algorithm. Surgical management ranges from transurethral resection of prostate (TURP) to minimally invasive surgical therapies (MIST) including laser therapies such as Holmium laser enucleation (HoLEP) and photoselective vaporisation (PVP), aquablation, Rezūm system, prostate artery embolisation (PAE), prostatic urethral lift (PUL), temporary implantable nitinol device (iTind) and Optilume BPH catheter system. BPO is a common urological condition that has a significant impact on quality of life and economic burden globally and is likely to become increasingly prevalent with an ageing population. Selecting the most appropriate treatment modality will depend on the individual patient preferences, availability of resources, cost, anatomical factors and the goals of treatment.

Urinary bladder retention secondary to intranasal administration of oxymetazoline "Afrin" for intra-arterial chemotherapy

Selective ophthalmic artery infusion of chemotherapy (SOAIC) has emerged as the standard of care for retinoblastoma (RB). Intranasal oxymetazoline (INO), Afrin, is often intraoperatively administered adjunctively to optimize flow to the orbit. There has been one report to date that suggests the adjunctive use of INO has led to systemic side effects. To our knowledge, this is the first documented case of INO causing urinary retention in a patient undergoing SOAIC, and the recommended treatment.

Vibegron shows high selectivity and potent agonist activity for β3-adrenoceptors, irrespective of receptor density

β3-Adrenoceptor (AR) agonists are used to treat patients with an overactive bladder (OAB). Clinical proof-of-concept data have been obtained for the β3-AR agonists vibegron, mirabegron, solabegron, and ritobegron; however, the selectivities of these agents have not been compared directly under the same experimental conditions. Moreover, the bladders of some patients express lower β3-AR densities than those of healthy individuals, and the β3-AR density might be expected to affect agonist activity. This study assessed the β3-AR selectivities of four β3-AR agonists and examined the effects of β-AR density on their pharmacological profiles. Functional cellular assays were performed using Chinese hamster ovary-K1 cells expressing three human β-AR subtypes transfected with different amounts of plasmid DNA (0.1, 0.05, 0.025 μg/well). The half-maximal effective concentration values, intrinsic activities (IAs), and β3-AR selectivities of vibegron, mirabegron, solabegron, and ritobegron were calculated to assess their pharmacological profiles. The β3-AR selectivities of vibegron, mirabegron, solabegron, and ritobegron were >7937-, 517-, 21.3-, and >124-fold higher than for β1-ARs, and >7937-, 496-, >362- and 28.1-fold higher than for β2-ARs, respectively, under the same experimental conditions. The IAs of mirabegron, solabegron, and ritobegron decreased in line with decreasing receptor density, while the IA of vibegron was maintained at the same level as that of the full agonist isoproterenol at various β3-AR densities. Vibegron has high β3-AR selectivity and exhibits full agonist activity, regardless of the β3-AR density. These results suggest that vibegron is a highly effective and safe drug for treating OAB.

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.

The Efficacy of Cyclooxygenase-2 Inhibitors for the Male Treatment of Lower Urinary Tract Symptoms: A Systematic Review and Meta-Analysis

To investigate the potential use of cyclooxygenase-2 (COX-2) inhibitors in the treatment of lower urinary tract symptoms (LUTS) in male patients, we conducted a comprehensive meta-analysis. Our study involved the identification and collection of randomized controlled trials (RCTs) from leading databases including PubMed, MEDLINE, EMBASE, and Cochrane Library. The primary objective of this analysis was to evaluate the effectiveness of COX-2 inhibitors for the treatment of LUTS. Our analysis involved six short-term (within 3 months) RCTs involving 707 patients. We found that COX-2 inhibitor treatment significantly improved the International Prostate Symptom Score (IPSS) of patients (mean difference [MD] = -2.99, 95% confidence interval (CI): -3.65 to -2.33, p < .00001), nocturia frequency (MD = -1.90; 95% CI: -3.18 to -0.61, p = .004), and maximum flow rate (Qmax) (MD = 1.02; 95% CI: 0.06 to 1.98, p = .04). However, no significant differences were found between patients in terms of changes in prostate-specific antigen (PSA) (MD = 0.02; 95% CI: -0.39 to 0.43, p = .92) and total prostate volume (TPV) (MD = -2.93; 95% CI: -6.45 to 0.59, p = .10). Therefore COX-2 inhibitors are an effective treatment for LUTS.

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.

The Emerging Role of Cell Adhesion Molecules on Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is a common disease in elderly men. It is characterized by prostatic enlargement and urethral compression and often causes lower urinary tract symptoms (LUTs) such as urinary frequency, urgency, and nocturia. Existing studies have shown that the pathological process of prostate hyperplasia is mainly related to the imbalance of cell proliferation and apoptosis, inflammation, epithelial-mesenchymal transition (EMT), and growth factors. However, the exact molecular mechanisms remain incompletely elucidated. Cell adhesion molecules (CAMs) are a group of cell surface proteins that mediate cell-cell adhesion and cell migration. Modulating adhesion molecule expression can regulate cell proliferation, apoptosis, EMT, and fibrotic processes, engaged in the development of prostatic hyperplasia. In this review, we went over the important roles and molecular mechanisms of cell adhesion molecules (mainly integrins and cadherins) in both physiological and pathological processes. We also analyzed the mechanisms of CAMs in prostate hyperplasia and explored the potential value of targeting CAMs as a therapeutic strategy for BPH.

Understanding and treating ejaculatory dysfunction in men with diabetes mellitus

Diabetes mellitus is a rapidly rising metabolic disorder with important systemic complications. Global figures have demonstrated the prevalence of diabetes mellitus has almost quadrupled from 108 million in 1980 to 422 million in 2014, with a current prevalence of over 525 million. Of the male sexual dysfunction resulting from diabetes mellitus, significant focus is afforded to erectile dysfunction. Nevertheless, ejaculatory dysfunction constitutes important sexual sequelae in diabetic men, with up to 35%-50% of men with diabetes mellitus suffering from ejaculatory dysfunction. Despite this, aspects of its pathophysiology and treatment are less well understood than erectile dysfunction. The main disorders of ejaculation include premature ejaculation, delayed ejaculation, anejaculation and retrograde ejaculation. Although ejaculatory dysfunction in diabetes mellitus can have complex multifactorial aetiology, understanding its pathophysiological mechanisms has facilitated the development of therapies in the management of ejaculatory dysfunction. Most of our understanding of its pathophysiology is derived from diabetic animal models; however, observational studies in humans have also provided useful information in elucidating important associative factors potentially contributing to ejaculatory dysfunction in diabetic men. These have provided the potential for more tailored treatment regimens in patients depending on the ejaculatory disorder, other co-existing sequelae of diabetes mellitus, specific metabolic factors as well as the need for fertility treatment. However, evidence for treatment of ejaculatory dysfunction, especially delayed ejaculation and retrograde ejaculation, is based on low-level evidence comprising small sample-size series and retrospective or cross-sectional studies. Whilst promising findings from large randomised controlled trials have provided strong evidence for the licensed treatment of premature ejaculation, similar robust studies are needed to accurately elucidate factors predicting ejaculatory dysfunction in diabetes mellitus, as well as for the development of pharmacotherapies for delayed ejaculation and retrograde ejaculation. Similarly, more contemporary robust data are required for fertility outcomes in these patients, including methods of sperm retrieval and assisted reproductive techniques in retrograde ejaculation.

Sinomenine Hydrochloride Can Ameliorate Benign Prostatic Hyperplasia by Lowering the 5α-Reductase 2 Level and Regulating the Balance between the Proliferation and Apoptosis of Cells

Benign prostatic hyperplasia (BPH) is a chronic disease that affects the quality of life of older males. Sinomenine hydrochloride (SIN) is the major bioactive alkaloid isolated from the roots of the traditional Chinese medicinal plant Sinomenium acutum Rehderett Wilson. We wondered if the SIN administration exerted a regulatory effect on BPH and its potential mechanism of action. Mice with testosterone propionate-induced BPH subjected to bilateral orchiectomy were employed for in vivo experiments. A human BPH cell line (BPH-1) was employed for in vitro experiments. SIN administration inhibited the proliferation of BPH-1 cells (p < 0.05) by regulating the expression of androgen-related proteins (steroid 5-alpha reductase 2 (SRD5A2), androgen receptors, prostate-specific antigen), apoptosis-related proteins (B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax)) and proliferation-related proteins (proliferating cell nuclear antigen (PCNA), mammalian target of rapamycin, inducible nitric oxide synthase) in vitro. SIN administration decreased the prostate-gland weight coefficient (p < 0.05) and improved the histological status of mice suffering from BPH. The regulatory effects of SIN administration on SRD5A2, an apoptosis-related protein (Bcl-2), and proliferation-related proteins (PCNA, matrix metalloproteinase-2) were consistent with in vitro data. SIN exerted a therapeutic effect against BPH probably related to lowering the SRD5A2 level and regulating the balance between the proliferation and apoptosis of cells. Our results provide an important theoretical basis for the development of plant medicines for BPH therapy.

The differences in the adrenergic receptors of proximal urethra between sexes

Objectives

The bladder and urethra work as a physiologically functional unit to facilitate continence in the storage and voiding phase. Sex differences have been found in the urethral contraction in response to α-adrenergic receptor activation. This study aimed to investigate the role of adrenergic receptors in the proximal urethra of male and female mice.

Materials and Methods

Urinary bladder and proximal urethral smooth muscle (USM) samples from male and female C57BL/6 mice were isolated and mounted in an organ bath.

Results

Acetylcholine-induced contraction of the urinary bladder was compared in male and female mice. Phenylephrine and norepinephrine (NE) induced little contraction at a lower concentration, but a relaxing phase of female proximal USM was observed at a higher concentration. This contraction profile was inhibited by NG-nitro-L-arginine, lidocaine, and capsaicin. In addition, the NE-induced contraction was greater in the incubation of propranolol than that of L-NNA or lidocaine. These results suggested that the β-adrenoceptor may be the dominant receptor of female proximal USM, and the activity of calcitonin gene-related peptide sensory nerves and nitrergic nerves may pose an anti-contraction effect on the proximal urethra in female mice.

Conclusion

β-adrenoceptor may be the dominant receptor of female proximal USM. The use of β-adrenergic receptor blocker agents might have the potential for the treatment of female voiding dysfunction.

Sex and Gender Differences in the Pharmacology of the Overactive Urinary Bladder

Dysfunction of the lower urinary tract in general and the overactive bladder syndrome (OAB) in particular are prevalent and have major impact on the quality of life of the afflicted patients and their partners. We concisely review sex and gender differences in patients and animal models in physiological bladder function, its alterations in disease (mostly OAB), and its responses to treatment. Women appear to have a smaller functional bladder capacity and, therefore, must void more often than men. On the other hand, men have a greater bladder outlet resistance, which is partly attributed to a longer urethra and partly to the presence of the prostate. Sex and gender differences in bladder contractility appear small and were not found consistently. The ability of bladder smooth muscle to relax may be somewhat smaller in females. However, females are heavily underrepresented in experimental studies on bladder function. Stress urinary incontinence is found predominantly in women (particularly those after childbirth). OAB is similarly prevalent in men and women. Females seek treatment much more often and are overrepresented in clinical trials. Treatment responses in OAB patients are similar in both genders for oral medications, but improvements upon injections of onabotulinum toxin type A appear smaller in men. We conclude that there is no evidence for major sex and gender differences in bladder dysfunction as related to OAB and its treatment responses, but female animals are heavily underrepresented in experimental studies.

Efficacy and safety of mirabegron in the treatment of overactive bladder syndrome after radical prostatectomy: a prospective randomized controlled study

Objectives

To evaluate the effects of mirabegron in the treatment of overactive bladder syndrome (OAB) after radical prostatectomy (RP).

Patients and methods

A total of 108 post-operative RP patients were randomly assigned to either the mirabegron (study) or the placebo (control) group. The Overactive Bladder Syndrome Self-Assessment Scale (OABSS) was selected as the primary endpoint, and the International Prostate Symptom Score (IPSS) and Quality of Life (QOL) score were selected as secondary endpoints. Statistical analysis was performed using IBM SPSS Statistics 26, and the treatment effects were compared between the two groups using independent samples t-test.

Results

In total, 55 patients were included in the study group and 53 patients in the control group. The mean age was(70.08 ± 7.54)years. There was no statistical difference in the baseline data between the two groups. OABSS scores decreased significantly in the study group compared to the control group during drug treatment (6.67 ± 1.06 vs. 9.14 ± 1.83, p < 0.01) and were better than the control group during the follow-up at week 8 and week 12. In addition, the decrease in IPSS scores (11.29 ± 3.89 and 15.34 ± 3.54, p<0.01) and the increase in QOL scores (2.40 ± 0.81 vs. 3.20 ± 1.00) were statistically significant in the study group. And the patients in the study group had better improvement in voiding symptoms and quality of life than the control group during the follow-up period.

Conclusion

Daily administration of 50 mg mirabegron after RP surgery significantly improved the symptoms of OAB after surgery with fewer side effects. Additional randomized controlled trials should be conducted in the future to further evaluate the efficacy and safety of mirabegron.

Treatment of benign prostatic hyperplasia and abnormal ejaculation: live imaging reveals tamsulosin - but not tadalafil - induced dysfunction of prostate, seminal vesicles and epididymis

In brief

One of the most commonly prescribed benign prostatic hyperplasia (BPH) pharmacotherapies, the alpha1-adrenergic blocker tamsulosin, is frequently discontinued, especially by younger patients due to ejaculatory disorders, often without feedback to the attending physician. Using a newly developed ex vivo system simulating sympathetic effects on the most relevant structures for the emission phase of ejaculation, that is seminal vesicles, prostate and the most distal part of the cauda epididymidis, we elucidated that tamsulosin fundamentally disturbed the obligatory noradrenaline-induced contractions in each of these structures which differed to an alternative pharmacotherapy, the PDE5 inhibitor tadalafil.

Abstract

Structures responsible for the emission phase of ejaculation are the seminal vesicles, the most distal part of the cauda epididymidis and the newly characterized prostate excretory ducts. The emission phase is mainly regulated by the sympathetic nervous system through alpha1-adrenergic receptor activation by noradrenaline at the targeted organs. BPH treatment with alpha1A-adrenergic antagonists such as tamsulosin is known to result in ejaculation dysfunction, often leading to discontinuation of therapy. Mechanisms of this disturbance remain unclear. We established a rodent model system to predict drug responses in tissues involved in the emission phase of ejaculation. Imitating the therapeutic situation, prostate ducts, seminal vesicles and the distal cauda epididymal duct were pre-incubated with the smooth muscle cell-relaxing BPH drugs tadalafil, a novel BPH treatment option, and tamsulosin in an ex vivo time-lapse imaging approach. Afterwards, noradrenergic responses in the relevant structures were investigated to simulate sympathetic activation. Noradrenaline-induced strong contractions ultimately lead to secretion in structures without pre-treatment. Contractions were abolished by tamsulosin in prostate ducts and seminal vesicles and significantly decreased in the epididymal duct. Such effects were not observed with tadalafil pre-treatment. Data visualized a serious dysfunction of each organ involved in emission by affecting alpha1-adrenoceptors localized at the relevant structures but not by targeting smooth muscle cell-localized PDE5 by tadalafil. Our model system reveals the mechanism of tamsulosin resulting in adverse effects during ejaculation in patients treated for BPH. These adverse effects on contractility do not apply to tadalafil treatment. This new knowledge translates directly to clinical medicine.

Efficacy and safety of adrenergic alpha-1 receptor antagonists in older adults: a systematic review and meta-analysis supporting the development of recommendations to reduce potentially inappropriate prescribing

BACKGROUND

Adrenergic alpha-1 receptor antagonists (alpha-1 antagonists) are frequently used medications in the management of lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH) and in the management of therapy-resistant arterial hypertension, two conditions frequently found in older adults. This systematic review aims at presenting a complete overview of evidence over the benefits and risks of alpha-1 antagonist treatment in people ≥ 65 years, and at deriving recommendations for a safe application of alpha-1 antagonists in older adults from the evidence found.

METHODS

A comprehensive literature search was performed (last update March 25th 2022) including multiple databases (Medline/Pubmed, Embase, the Cochrane Library) and using the PICOS framework to define search terms. The selection of the studies was done by two independent reviewers in a two-step approach, followed by a systematic data extraction. Quality appraisal was performed for each study included using standardised appraisal tools. The studies retrieved and additional literature were used for the development of recommendations, which were rated for strength and quality according to the GRADE methodology.

RESULTS

Eighteen studies were included: 3 meta-analyses, 6 randomised controlled trials and 9 observational trials. Doxazosin in the management of arterial hypertension was associated with a higher risk of cardiovascular disease, particularly heart failure, than chlorthalidone. Regarding treatment of LUTS suggestive of BPH, alpha-1 antagonists appeared to be effective in the relief of urinary symptoms and improvement of quality of life. They seemed to be less effective in preventing disease progression. Analyses of the risk profile indicated an increase in vasodilation related adverse events and sexual adverse events for some agents. The risk of falls and fractures as well as the effects of long-term treatment remained unclear. All meta-analyses and 5 out of 6 interventional studies were downgraded in the quality appraisal. 7 out of 9 observational studies were of good quality.

CONCLUSIONS

It cannot be recommended to use doxazosin as first-line antihypertensive agent neither in older adults nor in younger patients. In the management of BPH alpha-1 antagonists promise to effectively relieve urinary symptoms with uncertainty regarding their efficacy in preventing long-term progression events.

Evolving Role of Silodosin for the Treatment of Urological Disorders – A Narrative Review

Use of α-androgenic receptor blockers remains a mainstay therapeutic approach for the treatment of urological diseases. Silodosin is recommended over other α-blockers for the treatment of lower urinary tract symptoms (LUTS) and benign prostate hyperplasia (BPH), due to its high α_1A uroselectivity. Current research data suggest that silodosin is efficacious in the management of various urological diseases. Thus, we herein review the current evidence of silodosin related to its efficacy and tolerability and appraise the available literature that might ultimately aid in management of various urological conditions at routine clinical practice. Literature reveals that silodosin is beneficial in improving nocturia events related to LUTS/BPH. Silodosin exerts effect on relaxing muscles involved in detrusor obstruction, therefore prolonging the need for patients undergoing invasive surgery. Silodosin treatment, either as a monotherapy or combination, significantly improves International Prostate Symptom Score (IPSS) including both storage and voiding symptoms in patients with BPH/LUTS. Patients on other treatment therapies such as phosphodiesterase 5 inhibitors or other α-blockers are well managed with this drug. Steadily, silodosin has proved beneficial in the treatment of other urological disorders such as chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), overactive bladder/acute urinary retention (AUR), premature ejaculation (PE), and prostate cancer post brachytherapy-induced progression. In patients with distal ureteral stones, silodosin treatment is beneficial in decreasing stone expulsion time without affecting stone expulsion rate or analgesic need. Moreover, there were significant improvements in intravaginal ejaculation latency time, quality of life scores, and decrease in PE profile among patients with PE. Silodosin has also demonstrated promising results in increasing the likelihood of successful trial without catheter in patients with AUR and those taking antihypertensive drugs. Reports from Phase II studies have shown promising role of silodosin in the treatment of CP/CPPS as well as facilitating ureteral stone passage. From the robust data in this review, further silodosin treatment strategies in the management of different urological conditions need to be focused on.

Interactions between the Autonomic Nervous System and the Immune System after Stroke

Acute stroke is one of the leading causes of morbidity and mortality worldwide. Stroke-induced immune-inflammatory response occurs in the perilesion areas and the periphery. Although stroke-induced immunosuppression may alleviate brain injury, it hinders brain repair as the immune-inflammatory response plays a bidirectional role after acute stroke. Furthermore, suppression of the systemic immune-inflammatory response increases the risk of life-threatening systemic bacterial infections after acute stroke. Therefore, it is essential to explore the mechanisms that underlie the stroke-induced immune-inflammatory response. Autonomic nervous system (ANS) activation is critical for regulating the local and systemic immune-inflammatory responses and may influence the prognosis of acute stroke. We review the changes in the sympathetic and parasympathetic nervous systems and their influence on the immune-inflammatory response after stroke. Importantly, this article summarizes the mechanisms on how ANS regulates the immune-inflammatory response through neurotransmitters and their receptors in immunocytes and immune organs after stroke. To facilitate translational research, we also discuss the promising therapeutic approaches modulating the activation of the ANS or the immune-inflammatory response to promote neurologic recovery after stroke. © 2022 American Physiological Society. Compr Physiol 12:3665-3704, 2022.

Antagonism of α1-adrenoceptors by β3-adrenergic agonists: Structure-function relations of different agonists in prostate smooth muscle contraction

Effects of β₃-adrenergic agonists on prostate smooth muscle contraction are poorly characterized, although mirabegron is used for treatment of lower urinary tract symptoms. Off-target effects of several β₃-adrenergic agonists include antagonism of α₁-adrenoceptors. Proposed, but unconfirmed explanations include phenylethanolamine backbones, found in some β₃-adrenergic agonists and imparting interaction with catecholamine binding pockets of adrenoceptors. Here, we examined effects of β₃-adrenergic agonists on contractions of human prostate tissues, including ZD7114 (without phenylethanolamine moiety), ZD2079 (phenylethanolamine backbone), BRL37344 and CL316243 (chloride-substituted phenylethanolamine deriatives). Prostate tissues were obtained from radical prostatectomy. Contractions by α₁-adrenergic agonists and electric field stimulation (EFS) were studied in an organ bath. ZD7114 (10 µM) right-shifted concentration responses curves for α₁-adrenergic agonists, resulting in increased EC₅₀ values for phenylephrine, methoxamine and noradrenaline up to one magnitude, without affecting E_max values. ZD7114 (10 µM) inhibited EFS-induced contractions, resulting in reduced E_max values. All effects of ZD7114 were resistant to the β₃-adrenergic antagonist L-748337, including increases in EC₅₀ values for α₁-adrenergic agonists, up to more than two magnitudes. Using 10 µM, neither ZD2079, BRL37344 or CL316243 affected α₁-adrenergic or EFS-induced contractions. At escalated concentrations, BRL37344 (200 µM) right-shifted concentration response curves for phenylephrine, increased EC₅₀ values for phenylephrine, and inhibited EFS-induced contractions, while CL316243 (300 µM) did not affect phenylephrine- or EFS-induced contractions. In conclusion, phenylethanolamine backbones are not decisive to impart α₁-adrenoceptor antagonism to β₃-agonists. Effects of β₃-adrenergic agonists on prostate smooth muscle contraction are limited to off-target effects, including α₁-adrenoceptor antagonism by ZD7114 and BRL37344.

The urothelium: a multi-faceted barrier against a harsh environment

All mucosal surfaces must deal with the challenge of exposure to the outside world. The urothelium is a highly specialized layer of stratified epithelial cells lining the inner surface of the urinary bladder, a gruelling environment involving significant stretch forces, osmotic and hydrostatic pressures, toxic substances, and microbial invasion. The urinary bladder plays an important barrier role and allows the accommodation and expulsion of large volumes of urine without permitting urine components to diffuse across. The urothelium is made up of three cell types, basal, intermediate, and umbrella cells, whose specialized functions aid in the bladder's mission. In this review, we summarize the recent insights into urothelial structure, function, development, regeneration, and in particular the role of umbrella cells in barrier formation and maintenance. We briefly review diseases which involve the bladder and discuss current human urothelial in vitro models as a complement to traditional animal studies.

Clinical Utility of β3-Adrenoreceptor Agonists for the Treatment of Overactive Bladder: A Review of the Evidence and Current Recommendations

This nonsystematic review provides a summary of current evidence on the use of β₃-adrenoreceptor agonists (β₃-ARAs) for the treatment for lower urinary tract symptoms. Soon after their discovery in 1989, β₃-ARs were identified as a predominant adrenoreceptor subtype in the human urinary bladder. Although it is widely believed that β₃-ARAs cause detrusor relaxation, the effect on bladder afferent signaling likely plays an important role in their mechanism of action as well. In 2011 and 2012, mirabegron was approved for clinical use in overactive bladder (OAB) patients. Pooled analysis of data from prospective randomized studies on >60,000 OAB patients showed that when compared to placebo, mirabegron was superior with respect to reducing the frequency, number, and severity of urgency episodes, number of incontinence episodes and increasing dry rate, but not in reduction of nocturia episodes. The only side effect showing significantly higher incidence than placebo was nasopharyngitis. Mirabegron is approved for OAB treatment in all age-groups and in pediatric patients with neurogenic bladder. Vibegron is another β₃-ARA approved for OAB treatment in the US and Japan. Several large, multicenter, double-blind, randomized trials have documented statistically significant superiority of vibegron over placebo on all efficacy end points. Other β₃-ARAs are being developed; however, to date none has been introduced to clinical use. All β₃-ARAs provide efficacy similar to anticholinergics. They have a favorable safety profile and are well tolerated. Due to their different mechanisms of action, combination of β₃-ARAs with anticholinergic compounds allows for increased efficacy.

Comparative characterization of β-adrenoceptors in the bladder, heart, and lungs of rats: Alterations in spontaneously hypertensive rats

The present study aimed to characterize and compare β-adrenoceptors in the rat bladder with those in the heart and lungs of SD rats (8-10 weeks old) using subtype-selective agonists and antagonists in a radioligand binding assay with (-)-[125I]cyanopindolol ([125I]CYP), and also to clarify alterations in β-adrenoceptors in the bladder of spontaneously hypertensive rats (SHR) at 14 weeks old, from those of Wistar-Kyoto rats (WKY) and Wistar rats at the same age. A radioligand binding assay with [125I]CYP was used to measure β-adrenoceptor binding activity in rat tissues. Metoprolol exhibited the highest affinity to specific binding sites of [125I]CYP in the rat heart, indicating the dominance of β1-adrenoceptors. β3-selective agonists (BRL37344 and CL316243) and antagonist (SR59230A) exhibited higher affinity to specific binding sites of [125I]CYP in the bladder than in the heart and lungs. Furthermore, the binding affinity of the β2-selective antagonist, ICI118551 was the highest in the bladder. The Bmax of specific [125]CYP binding in the bladder was significantly lower in WKY and SHR than in Wistar rats. The present study provides further evidence for the coexistence of β2-and β3-adrenoceptors in the rat bladder, and indicates that β-adrenoceptor density is lower in the bladders of WKY and SHR.

Inhibition of human prostate smooth muscle contraction by the inhibitors of protein kinase C, GF109203X, and Go6983

INTRODUCTION

Prostate smooth muscle contraction is promoted by receptor-induced activation of intracellular signaling pathways. The presumed involvement in etiology and medical treatment of lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH) imparts a high clinical relevance to prostate smooth muscle contraction, which is contrasted by incomplete understanding at the molecular level. Involvement of protein kinase C (PKC) has been commonly assumed, but available studies were limited to nonhuman prostate smooth muscle or cell cultures. Here, we examined the effects of the PKC inhibitors Go6983 and GF109203x on contractions of human prostate tissues.

METHODS

Prostate tissues were obtained from radical prostatectomy. Contractions were induced by electric field stimulation (EFS), α₁ -adrenergic agonists (noradrenaline, phenylephrine, methoxamine), thromboxane A₂ analog U46619, endothelin-1, or calcium chloride in an organ bath.

RESULTS

GF109203X (500 nM) and Go6983 (300  nM) reduced EFS-, noradrenaline-, phenylephrine-, methoxamine-, and U46619-induced contractions of human prostate tissues, with maximum inhibitions approaching up to 55%. Using concentrations of 3 µM, GF109203X and Go6983 inhibited EFS- and noradrenaline-induced contractions, with similar effect sizes as 500 and 300 nM, respectively. Endothelin-1-induced contractions were not inhibited by GF109203X, and to neglectable extent by Go6983. After depolarization in calcium-free solution, calcium chloride-induced concentration-dependent contractions, which were inhibited by GF109203X and Go6983.

CONCLUSIONS

GF109203X and Go6983 inhibit neurogenic, α₁ -adrenergic, and thromboxane A₂ -induced smooth muscle contractions in the human prostate, suggesting a role of PKC for human prostate smooth muscle contraction. The inhibition may by be imparted by inhibition of calcium sensitivity.

Validation of Fenoterol to Study β2-Adrenoceptor Function in the Rat Urinary Bladder

Fenoterol is a β2-adrenoceptor (AR)-selective agonist that is commonly used to investigate relaxation responses mediated by β2-AR in smooth muscle preparations. Some data have questioned this because fenoterol had low potency in the rat urinary bladder when a muscarinic agonist was used as a pre-contraction agent and because some investigators proposed that fenoterol may act in part via β3-AR. We designed the present study to investigate whether fenoterol is a proper pharmacological tool to study β2-AR-mediated relaxation responses in the rat urinary bladder. Firstly, we have compared the effect of pre-contraction agents on fenoterol potency and found that fenoterol potency was about 1.5 log units greater against KCl than carbachol (pEC50 7.19 ± 0.66 and 5.62 ± 1.09 of KCl and of carbachol, respectively). To test the selectivity of fenoterol, we have determined the effects of the β2-AR antagonist ICI 118,551 and the β3-AR antagonist L 748,337 on relaxation responses to fenoterol. While 300 nM L 748,337 had little effect on the potency of fenoterol (pEC50 6.56 ± 0.25 and 6.33 ± 0.61 in the absence and presence of L 748,337, respectively), the relaxation curve for fenoterol was right-shifted in the presence 300 nM ICI 118,551 (pEC50 5.03 ± 0.18). Thus, we conclude that fenoterol is a proper pharmacological tool to assess β2-AR-mediated responses in the rat urinary bladder and most likely in other smooth-muscle preparations containing multiple subtypes of the β-AR.

Sexual Incentive Motivation and Copulatory Behavior in Male Rats Treated With the Adrenergic α2-Adrenoceptor Agonists Tasipimidine and Fadolmidine: Implications for Treatment of Premature Ejaculation

BACKGROUND

Premature ejaculation is the most common sexual dysfunction in young men, and it often leads to reduced relationship satisfaction and quality of life.

AIM

To determine the role of central and peripheral α₂-adrenoceptors in the control of ejaculation and sexual incentive motivation in rats.

METHODS

Sexual incentive motivation was studied in a large arena in which a male subject could choose between approaching and remaining close to a sexually receptive female or another male. Sexual behavior was studied in standard observation cages in which a male was allowed to freely interact with a receptive female for 30 minutes. Two highly selective agonists at the α₂-adrenoceptors, tasipimidine and fadolmidine, were administered before the tests. Low peripheral doses of fadolmidine have been reported to have effects mainly outside of the central nervous system, whereas at large doses also the central effects are evident.

OUTCOMES

The time spent close to the receptive female in relation to the time spent with the male and measures of ambulatory activity were obtained from the test for sexual incentive motivation, while the habitual parameters of sexual behavior were recorded with the copulation test.

RESULTS

Tasipimidine prolonged ejaculation latency and the interintromission interval at the dose of 200 µg/kg when data from fast-ejaculating rats were used. No other sexual parameter was modified. A dose of 100 µg/kg was ineffective. There was no consistent effect on sexual incentive motivation, although modest sedation was observed. Fadolmidine, a drug that does not easily penetrate the blood-brain barrier, had no effect on sexual incentive motivation at any of the doses used (3, 30, and 100 µg/kg). The largest dose had clear sedative effects. The lower doses had no systematic effect on sexual behavior, not even when only fast or very fast ejaculating males were analyzed.

CLINICAL TRANSLATION

The findings are relevant to the search for treatments for premature ejaculation that are specific enough to selectively delay ejaculation.

STRENGTHS & LIMITATIONS

The procedures used here are standard in the field and yield the most reliable data. Whether the effects observed in male rats are directly transferrable to men can only be determined through clinical studies.

CONCLUSION

The observation that drugs acting at central but not peripheral α₂-adrenoceptors prolong ejaculation latency without affecting any other parameter of sexual behavior or sexual incentive motivation suggests that this kind of drug may be suitable for treating premature ejaculation. Jyrki L., Elisa V.-A., Xi C., et al. Sexual Incentive Motivation and Copulatory Behavior in Male Rats Treated With the Adrenergic α₂-Adrenoceptor Agonists Tasipimidine and Fadolmidine: Implications for Treatment of Premature Ejaculation. J Sex Med 2021;18:1677-1689.

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.

Characterization of Urothelial Inclusions in Male Wistar Han Rats Treated Orally With the Novel α2A-Adrenoceptor Agonist Tasipimidine

Intracellular inclusions were observed in urinary bladder epithelium of male Wistar rats, following oral treatment with high doses of the α_2A-adrenoceptor agonist tasipimidine for 28 days. No cell death or inflammation was associated with the brightly eosinophilic inclusions. Electron microscopy (EM) studies showed that the inclusions represented intact or fragmented red blood cells (RBC) resulting from erythrophagocytosis, further supported by the presence of iron in urothelial cells. In addition, scattered iron-positive macrophages were observed in the submucosa and muscle layer, indicating microvascular leakage, as no major hemorrhage was evident. Despite the presence of inclusions, the urothelium showed normal uroplakin III distribution, normal cell turnover, and an absence of α-2u-globulin. It is, therefore, concluded that the inclusions were not associated with urothelial damage or increased renewal of the epithelium. This finding shows also that urothelial cells have the capability to phagocytize and break down RBCs originating from submucosal microvascular leakage. Similar changes were not observed in tasipimidine-treated beagle dogs (28 days), suggesting these findings were rat specific. The leakage of RBCs into the urothelium is suggested to be a consequence of exaggerated pharmacology leading to vasoconstriction of submucosal blood vessels in combination with transient increased bladder distension and pressure.

Concentration-dependent alpha1-Adrenoceptor Antagonism and Inhibition of Neurogenic Smooth Muscle Contraction by Mirabegron in the Human Prostate

Introduction: Mirabegron is available for treatment of storage symptoms in overactive bladder, which may be improved by β₃-adrenoceptor-induced bladder smooth muscle relaxation. In addition to storage symptoms, lower urinary tract symptoms in men include obstructive symptoms attributed to benign prostatic hyperplasia, caused by increased prostate smooth muscle tone and prostate enlargement. In contrast to the bladder and storage symptoms, effects of mirabegron on prostate smooth muscle contraction and obstructive symptoms are poorly understood. Evidence from non-human smooth muscle suggested antagonism of α₁-adrenoceptors as an important off-target effect of mirabegron. As α₁-adrenergic contraction is crucial in pathophysiology and medical treatment of obstructive symptoms, we here examined effects of mirabegron on contractions of human prostate tissues and on proliferation of prostate stromal cells.

Methods: Contractions were induced in an organ bath. Effects of mirabegron on proliferation, viability, and cAMP levels in cultured stromal cells were examined by EdU assays, CCK-8 assays and enzyme-linked immunosorbent assay.

Results: Mirabegron in concentrations of 5 and 10 μM, but not 1 µM inhibited electric field stimulation-induced contractions of human prostate tissues. Mirabegron in concentrations of 5 and 10 µM shifted concentration response curves for noradrenaline-, methoxamine- and phenylephrine-induced contractions to the right, including recovery of contractions at high concentrations of α₁-adrenergic agonists, increased EC₅₀ values, but unchanged E_max values. Rightshifts of noradrenaline concentration response curves and inhibition of EFS-induced contractions were resistant to L-748,337, l-NAME, and BPIPP. 1 µM mirabegron was without effect on α₁-adrenergic contractions. Endothelin-1- and U46619-induced contractions were not affected or only inhibited to neglectable extent. Effects of mirabegron (0.5–10 µM) on proliferation and viability of stromal cells were neglectable or small, reaching maximum decreases of 8% in proliferation assays and 17% in viability assays. Mirabegron did not induce detectable increases of cAMP levels in cultured stromal cells.

Conclusion: Mirabegron inhibits neurogenic and α₁-adrenergic human prostate smooth muscle contractions. This inhibition may be based on antagonism of α₁-adrenoceptors by mirabegron, and does not include activation of β₃-adrenoceptors and requires concentrations ranging 50-100fold higher than plasma concentrations reported from normal dosing. Non-adrenergic contractions and proliferation of prostate stromal cells are not inhibited by mirabegron.

Cardiovascular safety of vibegron, a new β3-adrenoceptor agonist, in older patients with overactive bladder: Post-hoc analysis of a randomized, placebo-controlled, double-blind comparative phase 3 study

AIMS

To examine the safety and efficacy of vibegron, a new β3-adrenoceptor agonist, in patients aged ≥65 years, with a focus on the effects on cardiovascular system and overactive bladder (OAB) symptoms.

METHODS

A post-hoc subgroup analysis was performed of a randomized, placebo-controlled, double-blind comparative phase 3 study of vibegron, including those assigned to receive either vibegron 50 mg (V50), vibegron 100 mg (V100), or placebo for 12 weeks. Subjects were stratified into two subgroups based on age: a <65-year subgroup and a ≥65-year subgroup. Safety (changes in systolic and diastolic blood pressure, pulse rate, and residual urine volume) and efficacy (changes in the numbers of micturitions, urgency episodes, urgency urinary incontinence [UUI] episodes, and the voided volume/micturition) were assessed in the subgroups treated with vibegron vs. placebo.

RESULTS

There were no significant differences in the cardiovascular outcomes (blood pressure and pulse rate), nor in the changes in residual urine volume, between the V50/100 and placebo groups in the <65-year or ≥65-year subgroup after 12-week treatment. Adverse events were slightly increased in the ≥65-year subgroup. In the efficacy analysis, V50/100 demonstrated similar efficacy in the <65-year and ≥65-year subgroups; an increasing trend in the voided volume/micturition was observed in subjects aged ≥65 years compared to subjects aged <65 years.

CONCLUSIONS

Vibegron was suggested to be similarly effective in patients ≥65 and <65 years and to have minimal influence on cardiovascular parameters.

Current Developments on the Role of α1-Adrenergic Receptors in Cognition, Cardioprotection, and Metabolism

The α₁-adrenergic receptors (ARs) are G-protein coupled receptors that bind the endogenous catecholamines, norepinephrine, and epinephrine. They play a key role in the regulation of the sympathetic nervous system along with β and α₂-AR family members. While all of the adrenergic receptors bind with similar affinity to the catecholamines, they can regulate different physiologies and pathophysiologies in the body because they couple to different G-proteins and signal transduction pathways, commonly in opposition to one another. While α₁-AR subtypes (α_1A, α_1B, α_1C) have long been known to be primary regulators of vascular smooth muscle contraction, blood pressure, and cardiac hypertrophy, their role in neurotransmission, improving cognition, protecting the heart during ischemia and failure, and regulating whole body and organ metabolism are not well known and are more recent developments. These advancements have been made possible through the development of transgenic and knockout mouse models and more selective ligands to advance their research. Here, we will review the recent literature to provide new insights into these physiological functions and possible use as a therapeutic target.

The Influence of an Adrenergic Antagonist Guanethidine on the Distribution Pattern and Chemical Coding of Caudal Mesenteric Ganglion Perikarya and Their Axons Supplying the Porcine Bladder

This study was aimed at disclosing the influence of intravesically instilled guanethidine (GUA) on the distribution, relative frequency and chemical coding of both the urinary bladder intramural sympathetic nerve fibers and their parent cell bodies in the caudal mesenteric ganglion (CaMG) in juvenile female pigs. GUA instillation led to a profound decrease in the number of perivascular nerve terminals. Furthermore, the chemical profile of the perivascular innervation within the treated bladder also distinctly changed, as most of axons became somatostatin-immunoreactive (SOM-IR), while in the control animals they were found to be neuropeptide Y (NPY)-positive. Intravesical treatment with GUA led not only to a significant decrease in the number of bladder-projecting tyrosine hydroxylase (TH) CaMG somata (94.3 ± 1.8% vs. 73.3 ± 1.4%; control vs. GUA-treated pigs), but simultaneously resulted in the rearrangement of their co-transmitters repertoire, causing a distinct decrease in the number of TH⁺/NPY⁺ (89.6 ± 0.7% vs. 27.8 ± 0.9%) cell bodies and an increase in the number of SOM-(3.6 ± 0.4% vs. 68.7 ± 1.9%), calbindin-(CB; 2.06 ± 0.2% vs. 9.1 ± 1.2%) or galanin-containing (GAL; 1.6 ± 0.3% vs. 28.2 ± 1.3%) somata. The present study provides evidence that GUA significantly modifies the sympathetic innervation of the porcine urinary bladder wall, and thus may be considered a potential tool for studying the plasticity of this subdivision of the bladder innervation.

The clinical significance of abnormal ejaculation by silodosin. Is it important?

We aimed to evaluate the effect of the abnormal ejaculation (AEj) on patients using silodosin in terms of drug cessation. We also analysed the possible factors that may affect the decisions of patients with AEj to proceed or change their medication. The patients (n = 118) treated with silodosin 8 mg daily were prospectively analysed. In order to evaluate the erectile function, ejaculatory function, depression and sexual satisfaction; IIEF, MSHQ-EjD, Beck's depression and Golombok-Rust questionnaires were given to patients respectively. Patients were re-evaluated at the 3rd month of their treatment. The rate of AEj was 52.5%. Nearly 42% of the patients with AEj desired to stop their medication whereas it was 7.1% at patients without AEj (p < .001). The pre-treatment International Prostate Symptom Score (IPSS) and the decrease in IPSS score were significantly lower in patients who demand to stop their treatment (p < .05). AEj was significantly higher in patients who wanted to stop their medication (p < .001). Even if they had an AEj, patients who were happy with the clinical efficacy of silodosin did not want to change their drug. In addition to this, pre-treatment ejaculatory status was an important indicator for patients to decide drug cessation due to AEj side effect of silodosin.

Primary aldosteronism is associated with risk of urinary bladder stones in a nationwide cohort study

We analyzed database from the Taiwan National Health Insurance to investigate whether primary aldosteronism (PA) increases the risk of bladder stones. This retrospective nationwide population-based cohort study during the period of 1998–2011 compared patients with and without PA extracted by propensity score matching. Cox proportional hazard models and competing death risk model were used to estimate the hazard ratios (HRs), sub-hazard ratios (SHRs) and corresponding 95% confidence intervals (CIs). There were 3442 patients with PA and 3442 patients without PA. The incidence rate of bladder stones was 5.36 and 3.76 per 1000 person-years for both groups, respectively. In adjusted Cox hazard proportional regression models, the HR of bladder stones was 1.68 (95% CI 1.20–2.34) for patients with PA compared to individuals without PA. Considering the competing risk of death, the SHR of bladder stones still indicates a higher risk for PA than a comparison cohort (SHR, 1.79; 95% CI 1.30–2.44). PA, age, sex, and fracture number were the variables significantly contributing to the formation of bladder stones. In conclusion, PA is significantly associated with risk of bladder stones.

Current Treatment for Benign Prostatic Hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) is characterized by the occurrence of.disorders of urine storage and bladder emptying. Most men over the age of 60 years are affected to some degree.

METHODS

A selective literature search with additional scrutiny of guidelines and meta-analyses.

RESULTS

The management of patients with BPH is complex. Emptying and retention disorders can be treated by various pharmacological and surgical means. Transurethral resection of the prostate (TURP) has long been considered the gold standard for operative treatment. Transurethral enucleation procedures show a better risk profile in some uses, however, and have, above all, largely displaced suprapubic prostatectomy. Numerous innovative treatment options have been developed in recent years, but their long-term effects remain to be determined. These treatment techniques can nevertheless be used in individual cases after thorough discussion with the patient.

CONCLUSION

The care of patients with BPH should be interdisciplinary. The efficacy and safety of many new developments in the area of pharmacological and minimally invasive treatment remain to be demonstrated in randomized trials.

Role of Ano1 Ca2+-activated Cl- channels in generating urethral tone

Urinary continence is maintained in the lower urinary tract by the contracture of urethral sphincters, including smooth muscle of the internal urethral sphincter. These contractions occlude the urethral lumen, preventing urine leakage from the bladder to the exterior. Over the past 20 years, research on the ionic conductances that contribute to urethral smooth muscle contractility has greatly accelerated. A debate has emerged over the role of interstitial cell of Cajal (ICC)-like cells in the urethra and their expression of Ca²⁺-activated Cl^- channels encoded by anoctamin-1 [Ano1; transmembrane member 16 A (Tmem16a) gene]. It has been proposed that Ano1 channels expressed in urethral ICC serve as a source of depolarization for smooth muscle cells, increasing their excitability and contributing to tone. Although a clear role for Ano1 channels expressed in ICC is evident in other smooth muscle organs, such as the gastrointestinal tract, the role of these channels in the urethra is unclear, owing to differences in the species (rabbit, rat, guinea pig, sheep, and mouse) examined and experimental approaches by different groups. The importance of clarifying this situation is evident as effective targeting of Ano1 channels may lead to new treatments for urinary incontinence. In this review, we summarize the key findings from different species on the role of ICC and Ano1 channels in urethral contractility. Finally, we outline proposals for clarifying this controversial and important topic by addressing how cell-specific optogenetic and inducible cell-specific genetic deletion strategies coupled with advances in Ano1 channel pharmacology may clarify this area in future studies.NEW & NOTEWORTHY Studies from the rabbit have shown that anoctamin-1 (Ano1) channels expressed in urethral interstitial cells of Cajal (ICC) serve as a source of depolarization for smooth muscle cells, increasing excitability and tone. However, the role of urethral Ano1 channels is unclear, owing to differences in the species examined and experimental approaches. We summarize findings from different species on the role of urethral ICC and Ano1 channels in urethral contractility and outline proposals for clarifying this topic using cell-specific optogenetic approaches.

Discovering pathways in benign prostate hyperplasia: A functional genomics pilot study

Benign prostate hyperplasia (BPH) is one of the well-known urological neoplasms common in males with an increasing number of associated deaths in aging males. It causes uncomfortable urinary symptoms, including urine flow blockage, and may cause bladder, urinary tract or kidney problems. The histopathological and clinical knowledge regarding BPH is limited. In the present study, an in silico approach was applied that uses genome-scale microarray expression data to discover a wide range of protein-protein interactions in addition to focusing on specific genes responsible for BPH to develop prognostic biomarkers. Various genes that were differentially expressed in BPH were identified. Gene and functional annotation clusters were determined and an interaction analysis with disease phenotypes of BPH was performed, as well as an RNA tissue specificity analysis. Furthermore, a molecular docking study of certain short-listed gene biomarkers, namely anterior gradient 2 (AGR2; PDB ID: 2LNT), steroid 5α-reductase 2 (PDB ID: 6OQX), zinc finger protein 3 (PDB ID: 5T00) and collagen type XII α1 chain (PDB ID: 1U5M), was performed in order to identify alternative Chinese herbal agents for the treatment of BPH. Data from the present study revealed that AGR2 receptor (PDB ID: 2LNT) and berberine (Huang Bo) form the most stable complex and therefore may be assessed in further pharmacological studies for the treatment of BPH.

Purinergic smooth muscle contractions in the human prostate: estimation of relevance and characterization of different agonists

Non-adrenergic prostate smooth muscle contractions may account for the limited effectiveness of α₁-adrenoceptor antagonists, which are the first-line option for medical treatment of voiding symptoms suggestive of benign prostatic hyperplasia. In non-human prostates, purinergic agonists induce contractions reaching similar magnitudes as α₁-adrenergic contractions. However, evidence for the human prostate is highly limited, and pointed to much weaker purinergic contractions. Here, we examined contractions of different purinergic agonists in human prostate tissues. Tissues were obtained from radical prostatectomy. Contractions were studied in an organ bath, and expression of purinergic receptors was studied by RT-PCR. Electric field stimulation (EFS)–induced contractions amounted to 104% of KCl-induced contractions (95% CI: 84–124%). From all tested agonists, only ATP induced concentration-dependent contractions, reaching an average maximum of 18% (12–24%) of KCl. Maximum tensions following application of other agonists averaged to 7.1% of KCl for α,β-methylene-ATP (1.8–12.4%), 3.9% for β,γ-methylene-ATP (2.0–5.4%), 3.1% for 2-methylthio-ATP (− 0.1–6.3%), and 5.1% for ATPγS (1.0–9.2%). Responses were not affected by the P2X antagonist NF023 or the P2Y antagonist PPADS. mRNA expression of P2X1-4 correlated with expression of a marker for catecholaminergic nerves, although neither ATP, NF023, nor PPADS changed EFS-induced contractions. Correlation between expression of receptors and the smooth muscle marker calponin was not observed. Our findings point to a low relevance of purinergic contractions in the human prostate, compared to other contractile stimuli in the human prostate and compared to purinergic contractions in non-human prostates. Purinergic contractions in the human prostate are not sensitive to NF023 or PPADS.

Acute Kidney Injury Caused by Obstructive Nephropathy

Acute kidney injury secondary to obstructive nephropathy is a frequent event that accounts for 5 to 10% of all acute kidney injury cases and has a great impact on the morbidity and mortality in those affected. The obstruction in the urinary tract has a profound impact on kidney function due to damage produced by ischemic and inflammatory factors that have been associated with intense fibrosis. This pathology is characterized by its effects on the management of fluids, electrolytes, and the acid-base mechanisms by the renal tubule; consequently, metabolic acidosis, hyperkalemia, uremia, and anuria are seen during acute kidney injury due to obstructive nephropathy, and after drainage, polyuria may occur. Acute urine retention is the typical presentation. The diagnosis consists of a complete medical history and should include changes in urinary voiding and urgency and enuresis, history of urinary tract infections, hematuria, renal lithiasis, prior urinary interventions, and constipation. Imaging studies included tomography or ultrasound in which hydronephrosis can be seen. Management includes, in addition to drainage of the obstructed urinary tract system, providing supportive treatment, correcting all the metabolic abnormalities, and initiating renal replacement therapy when required. Although its recovery is in most cases favorable, it seems to be an undervalued event in nephrology and urology. This is because it is mistakenly believed that the resolution and recovery of kidney function is complete once the urinary tract is unobstructed. It can have serious kidney sequelae. In this review, we report the epidemiology, incidence, pathophysiological mechanisms, diagnosis, and treatment of acute kidney injury due to obstructive nephropathy.

Intravesical dexmedetomidine instillation reduces postoperative catheter-related bladder discomfort in male patients under general anesthesia: a randomized controlled study

Background

The catheter-related bladder discomfort (CRBD) of male patients is a common clinical problem, albeit lacking effective solutions. The present study aimed to investigate whether intravesical dexmedetomidine instillation alleviates the postoperative urinary discomfort in male patients with catheter under general anesthesia.

Methods

This single-blinded, prospective, randomized study included a total of 167 male patients American Society of Anesthesiologists (ASA) physical status I-II scheduled for surgery under general anesthesia were allocated to two groups: 84 in the dexmedetomidine group and 83 in the control group. Dexmedetomidine group patients received intravesical instillation of the drug 0.5 μg/kg and normal saline 20 mL, while the control group received intravesical instillation of 20 mL normal saline. The catheter was clamped for 30 min after intravesical instillation for all patients. CRBD scores and urethra pain numerical rating scale (NRS) scores were measured at admittance to post-anesthesia care unit (PACU) (T0), intravesical instillation (T1), 30 min (T2), 60 min (T3), 2 h (T4) after intravesical instillation, discharged from PACU (T5), and 6 h (T6) and 24 h (T7) after the operation. Patient satisfaction at discharge from PACU and 24 h post-operation were compared between the two groups.

Results

CRBD scores and urethra pain NRS scores after 30 min of intravesical dexmedetomidine instillation to 24 h post-operation were significantly lower than the control group (p < 0.001), and patient satisfaction was higher at discharge from PACU and 24 h post-operation (p < 0.001). No differences were detected in Steward score out of PACU (p = 0.213) and from the time of the end of operation to fully awake (p = 0.417).

Conclusion

Intravesical dexmedetomidine instillation reduces postoperative urinary discomfort and urethra pain and improves satisfaction in male patients under general anesthesia.

Trial registration

Chinese Clinical Trial Registry (No. ChiCTR1800016429), date of registration 1st June 2018.

Cystocerebral Syndrome: An Updated Review and a New Proposed Mechanism for an Often Forgotten Cause of Delirium

Cystocerebral syndrome is an often forgotten cause of delirium in elderly males, which is quite easily treated. We reviewed the current body of literature documenting cystocerebral syndrome and proposed a new mechanism of action explaining why all patients identified thus far have been male.

Data was obtained from articles describing cases of cystocerebral syndrome, urinary retention, and confusion in addition to delirium via a PubMed database search. We reviewed all articles describing cases of cystocerebral syndrome via the PubMed database using the Medical Subject Headings (MeSH) keywords of "cystocerebral syndrome,” urinary retention and confusion," and "delirium and urinary retention or cystocerebral syndrome," and identified eight cases of cystocerebral syndrome including the original publication by Blackburn and Dunn.

We found that all patients reported in the literature were males older than 70 years and often with concomitant benign prostatic hypertrophy (BPH) who presented with acute episodes of delirium that rapidly responded to bladder decompression.

The authors seek to update the medical community regarding this uncommon phenomenon of delirium in elderly male patients. We also propose that the lack of female patients in the literature is reflective of their decreased intraurethral flow resistance as is currently being described in other avenues of research in the field of urodynamics.

α1-adrenoceptor activity of β-adrenoceptor ligands - An expected drug property with limited clinical relevance

Many β-adrenoceptor agonists and antagonists including several clinically used drugs have been reported to also exhibit binding to α₁-adrenoceptors. Such promiscuity within the adrenoceptor family appears to occur more often than off-target effects of drugs in general. It should not be considered surprising based on the amino acid homology among the nine adrenoceptor subtypes including the counter-ions for binding the endogenous catecholamines. When β-adrenoceptor ligands also bind to α₁-adrenoceptors, they almost always act as antagonists, regardless of being agonists or antagonists at the β-adrenoceptor. The α₁-adrenoceptor affinity of β-adrenoceptor ligands in most cases is at least one, and often more log units lower than at their cognate receptor. Consistent evidence from multiple investigators indicates that β-adrenoceptor ligands relatively have the highest affinity for α_1A- and lowest for α_1B-adrenoceptors. While promiscuity among adrenoceptor subtypes causes misleading interpretation of experimental in vitro data, it is proposed based on the law of mass action that α₁-adrenoceptor binding of β-adrenoceptor ligands rarely contributes to the clinical profile of such drugs, particularly if they are agonists at the β-adrenoceptor.

Silodosin improves functional consequences of lower urinary tract obstruction secondary to benign prostate hypertrophy, a proof of concept study in the spontaneously hypertensive rat supplemented with testosterone

Background

The main purpose of this study is to investigate the effect of silodosin on the urodynamic consequences in a previously established model of lower urinary tract symptoms associated with benign prostate hyperplasia, the spontaneously hypertensive rats (SHR) supplemented with testosterone.

Methods

Three groups of animals (8-week-old; n = 10/group) were considered: Wistar Kyoto (control) rats (WKY), SHR supplemented with testosterone at 3 mg/kg/day and treated with either vehicle (SHR-T, n = 10) or silodosin at 0.1 mg/kg/day (SHR-T + silodosin, n = 10) by oral gavage for 6 weeks. Cystometry experiments were performed. The bladder was harvested, weighed and paraffin-embedded for morphometric analysis. The prostate was also harvested and weighed.

Results

The number of animals included in the analysis were n = 10/10 for WKY and n = 7–8/10 for each SHR rats supplemented with testosterone group. SHR-T displayed a significant decrease in the intercontraction interval, infused volume and mean flow rate whereas the frequency of non-voiding contractions was increased. Silodosin improved the voiding behavior of SHR-T by significantly increasing the intercontraction interval, the infused volume and the mean flow rate and decreasing the number of non-voiding contractions. SHR-T displayed a significant increase in prostate and bladder weights and a 15% increase in the detrusor wall area compared to WKY.

Conclusions

Chronic silodosin treatment relieved storage symptoms in SHR supplemented with testosterone and decreased the frequency of non-voiding detrusor contractions during the filling phase.