Urodynamic effects of alpha-adrenoceptor blockers: a review of clinical trials

Isoform-independent promotion of contractility and proliferation, and suppression of survival by with no lysine/K kinases in prostate stromal cells

With no lysine/K kinases (WNKs) promote vasocontraction and vascular smooth muscle cell proliferation. In the prostate, smooth muscle contraction and growth may be critical for the development and medical treatment of voiding symptoms in benign prostatic hyperplasia. Here, we examined the effects of isoform-specific WNK silencing and of the WNK inhibitor WNK463 on growth-related functions and contraction in prostate stromal cells, and in human prostate tissues. Impacts of WNK silencing by transfection of cultured stromal cells with isoform-specific siRNAs were qualitatively and quantitatively similar for each WNK isoform. Effects of silencing were largest on cell death (3-5 fold increase in annexin V-positive/7-AAD-positive cells), on proliferation rate, Ki-67 mRNA expression and actin organization (reduced around two-thirds). Contraction in matrix contraction assays and viability were reduced to a lower degree (approximately half), but again to a similar extent for each WNK isoform. Effects of silencing were quantitatively and qualitatively reproduced by 10 μM WNK463, while 1 μM still induced cell death and breakdown in actin organization, without affecting proliferation or viability. Using 500 nM and 10 μM, WNK463 partly inhibited neurogenic and U46619-induced contractions of human prostate tissues (around half), while inhibition of α1-adrenergic contractions (around half) was limited to 10 μM. All four WNK isoforms suppress cell death and promote proliferation in prostate stromal cells. WNK-driven contraction of stromal cells appears possible, even though to a limited extent. Outcomes of isoform-specific WNK silencing can be fully reproduced by WNK463, including inhibition of smooth muscle contraction in human prostate tissues, but require high concentrations.

Silencing of CDC42 inhibits contraction and growth-related functions in prostate stromal cells, which is mimicked by ML141

BACKGROUND

Prostate smooth muscle contraction and stromal growth may contribute to lower urinary tract symptoms suggestive of benign prostatic hyperplasia, but are incompletely understood. A role of the monomeric GTPase CDC42 for smooth muscle contraction and proliferation appears possible, but is unknown for the prostate. Here, we silenced CDC42 expression in prostate stromal cells (WPMY-1), and examined contractility, growth-related functions and responses to the presumed CDC42 inhibitor, ML141.

METHODS

WPMY-1 cells were transfected with scrambled or CDC42-specific siRNA, and characterized for GTPase activities, contraction, proliferation, colony formation, apoptosis, cell death and viability. Effects of ML141 were examined in cells with and without silencing.

RESULTS

CDC42 silencing was confirmed by reduced mRNA and protein expression, and reduced CDC42 activity. Silencing impaired contraction (23-47 %), actin organization (25 %), proliferation (17-63 %), colony formation and viability (64-89 %), and increased the percentage of dead cells (2.6-fold). ML141 mimicked the phenotype of silencing in scrambled siRNA-transfected controls, and in non-transfected WPMY-1 cells, including inhibition of contraction, proliferation, colony formation and viability, breakdown of actin organization and increased cell death. In CDC42-silenced cells, ML141 still affected phalloiding organization, proliferation and cell death, with effect sizes resembling controls without silencing. ML141 inhibited RhoA activity in CDC42-silenced cells, but not in cells without silencing.

CONCLUSIONS

CDC42 promotes contraction of prostate stromal cells, and drives stromal growth by CDC42-mediated proliferation and suppression of apoptosis-independent cell death. ML141 mimicks all effects of CDC42 silencing, but its specificity may be limited and depends on GTPase phenotypes of cells.

Inhibition of growth and contraction in human prostate stromal cells by silencing of NUAK1 and -2, and by the presumed NUAK inhibitors HTH01-015 and WZ4003

Background: NUAKs promote myosin light chain phosphorlyation, actin organization, proliferation and suppression of cell death in non-muscle cells, which are critical for smooth muscle contraction and growth. In benign prostatic hyperplasia (BPH), contraction and growth in the prostate drive urethral obstruction and voiding symptoms. However, a role of NUAKs in smooth muscle contraction or prostate functions are unknown. Here, we examined effects of NUAK silencing and the presumed NUAK inhibitors, HTH01-015 and WZ4003 on contraction and growth-related functions in prostate stromal cells (WPMY-1) and in human prostate tissues. Methods: Effects of NUAK1 and -2 silencing, HTH01-015 and WZ4003 on matrix plug contraction, proliferation (EdU assay, Ki-67 mRNA), apoptosis and cell death (flowcytometry), viability (CCK-8) and actin organization (phalloidin staining) were examined in cultured WPMY-1 cells. Effects of HTH01-015 and WZ4003 on smooth muscle contraction were assessed in organ bath experirments with human prostate tissues. Results: Effects of silencing were most pronounced on proliferation and cell death, resulting in decreases of proliferation rate by 60% and 70% by silencing of NUAK1 and NUAK2 (compared to scramble siRNA-transfected controls), decreases in Ki-67 by 75% and 77%, while numbers of dead cells after silencing of NUAK1 and NUAK2 amounted to 2.8 and 4.9 fold of scramble-transfected controls. Silencing of each isoform was paralleled by reduced viability, breakdown in actin polymerization, and partial decreases in contractility (maximally 45% by NUAK1 silencing, 58% by NUAK2 silencing). Effects of silencing were mimicked by HTH01-015 and WZ4003, with numbers of dead cells amounting up to 16.1 fold or 7.8 fold with HTH01-015 or WZ4003, compared to solvent-treated controls. Using concentrations of 500 nM, neurogenic contractions of prostate tissues were inhibited partly by HTH01-015 and U46619-induced contractions were inhibited partly by HTH01-015 and WZ4003, while α₁-adrenergic and endothelin-1-induced contractions remained unaffected. Using 10 μM, inhibition of endothelin-1-induced contractions by both inhibitors and inhibition of α₁-adrenergic contractions by HTH01-015 added to effects seen by 500 nM. Conclusion: NUAK1 and -2 suppress cell death and promote proliferation in prostate stromal cells. A role in stromal hyperplasia appears possible in BPH. Effects of NUAK silencing are mimicked by HTH01-015 and WZ4003.

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.

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.

New strategies for inhibition of non-adrenergic prostate smooth muscle contraction by pharmacologic intervention

BACKGROUND

Inhibition of prostate smooth muscle contraction by α₁ -adrenoceptor antagonists (α₁ -blockers) is a first-line medical treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia. Increased smooth muscle tone in the hyperplastic prostate may drive urethral obstruction, resulting in bladder outlet obstruction and voiding symptoms. However, efficacy of α₁ -blockers is limited, as non-adrenergic mediators including endothelin-1 and thromboxane A₂ (TXA₂ ) increase prostate smooth muscle tension in parallel to α₁ -adrenoceptors. This may maintain urethral obstruction despite therapy with α₁ -blockers. Consequently, future treatment options with higher efficacy need to target α₁ -adrenergic and non-adrenergic contractions simultaneouly. Recently, several compounds were reported to inhibit adrenergic or neurogenic prostate contractions, however, their effects on non-adrenergic contraction are unknown. Here, we examined effects of inhibitors for Rac-GTPase, Src family kinases (SFKs), and p21-activated kinases (PAKs) on non-adrenergic prostate contractions.

METHODS

Prostate tissues were obtained from radical prostatectomy. Contractions were studied in an organ bath. Viability of cultured stromal cells was assessed by CCK-8 assay.

RESULTS

Inhibition of α₁ -adrenergic contractions by Rac inhibitors EHT1864 (100 μM) and NSC23766 (100 μM), and SFK inhibitors AZM475721 (10 μM) and PP2 (10 μM) was confirmed by inhibition of methoxamine-induced contractions. No effects of the PAK inhibitors FRAX486 (30 μM) and IPA3 (300 μM) on α₁ -adrenergic contraction were confirmed by absent effects on methoxamine-inuced contractions. EHT1864 caused inhibition of endothelin-1- and U46619-induced contractions. EHT1864 reduced the viability of stromal cells concentration- and time-dependently. EHT1864 attenuated KCl-induced contractions of prostate strips only slightly, so that toxic effects may not account alone for inhibition of agonist-induced contractions. NSC23766 inhibited U46619-induced contractions, but not endothelin-1-induced contractions. AZM475271 had no effects on endothelin-1- or U46619-induced contractions, while PP2 inhibited U46619- but not endothelin-1-induced contractions. FRAX486 caused inhibition of U46619-induced contractions. IPA3 inhibited U46619-, but not endothelin-1-induced contractions.

CONCLUSIONS

Of all six inhibitors, EHT1864 seems to be most promising from a translational point of view, as it inhibited TXA₂ - and endothelin-1-induced besides α₁ -adrenergic prostate contractions. This reflects divergent pharmacologic profiles of EHT1864 and NSC23766, although both are Rac-GTPase inhibitors. In vivo, urodynamic effects of EHT1864 and possibly of FRAX486 may exceed those of α₁ -blockers.

Inhibition of human prostate smooth muscle contraction by the LIM kinase inhibitors, SR7826 and LIMKi3

BACKGROUND AND PURPOSE

In men with benign prostatic hyperplasia, increased smooth muscle tone in the prostate may lead to bladder outlet obstruction and subsequent lower urinary tract symptoms. Consequently, medical treatment aims to inhibit prostate smooth muscle contraction. However, the efficacy of the treatment options available is limited, and improved understanding of mechanisms of prostate smooth muscle contraction and identification of new targets for medical intervention are mandatory. Several studies suggest that LIM kinases (LIMKs) promote smooth muscle contraction; however, this has not yet been examined. Here, we studied effects of the LIMK inhibitors on prostate smooth muscle contraction.

EXPERIMENTAL APPROACH

Human prostate tissues were obtained from radical prostatectomy. Phosphorylation of cofilin, a LIMK substrate, was examined using a phospho-specific antibody. Smooth muscle contractions were studied in organ bath experiments.

KEY RESULTS

Real-time PCR, Western blot and immunofluorescence suggested LIMKs are expressed in smooth muscle cells of prostate tissues. Two different LIMK inhibitors, SR7826 (1 μM) and LIMKi3 (1 μM), inhibited contractions of prostate strips, which were induced by electrical field stimulation, α₁ -adrenoceptor agonists phenylephrine and methoxamine and the TXA₂ analogue, U46619. LIMK inhibition in prostate tissues and cultured stromal cells (WPMY-1) was confirmed by cofilin phosphorylation, which was reduced by SR7826 and LIMKi3. In WPMY-1 cells, SR7826 and LIMKi3 caused breakdown of actin filaments and reduced viability.

CONCLUSIONS AND IMPLICATIONS

Smooth muscle tone in the hyperplastic human prostate may underlie the effects of LIMKs, which promote contraction. Contraction of prostate strips can be inhibited by small molecule LIMK inhibitors.

Serenoa repens + selenium + lycopene vs tadalafil 5 mg for the treatment of lower urinary tract symptoms secondary to benign prostatic obstruction: a Phase IV, non-inferiority, open-label, clinical study (SPRITE study)

OBJECTIVE

To compare in a randomised, open-label, non-inferiority clinical study, the efficacy and tolerability of Serenoa repens (SeR) + selenium (Se) + lycopene (Ly) (SeR-Se-Ly) therapy vs tadalafil 5 mg in men with lower urinary tract symptoms (LUTS).

PATIENTS AND METHODS

From May 2015 to January 2017, 427 patients were enrolled in 21 different centres (International Standard Randomised Controlled Trial Number Register [ISRCTN] 73316039). Inclusion criteria included: age between 50 and 80 years, International Prostate Symptom Score (IPSS) ≥12, maximum urinary flow rate (Q_max ) ≤ 15 mL/s, and post-void residual (PVR) <100 mL. Patients were randomised into two groups in a 2:1 ratio: Group A (SeR-Se-Ly, 1 tablet daily for 6 months) and Group B (tadalafil 5 mg, 1 tablet daily for 6 months). The primary endpoint of the study was the non-inferior variation in the IPSS and Q_max in Group A vs Group B after 6 months of treatment.

RESULTS

In all, 404 patients completed the full protocol. When comparing both therapies, Group A was statistically not inferior to Group B considering the median change in IPSS (-3.0 vs -3.0; P < 0.01), IPSS quality of life (-2.0 vs -2.0; P < 0.05), and Q_max (2.0 vs 2.0 mL/s; P < 0.01). We found statistically significant differences in the increase of at least 3 points in Q_max (38.2% vs 28.1%; P = 0.04) and of at least 30% of Q_max (39.2% vs 27.3%; P < 0.01) in Group A compared to Group B. The percentage of patients with an increase of at least 3 points in the IPSS and a decrease of at least 25% of the IPSS was not statistically different between the two groups. For adverse events, four patients in Group A (1.44%) and 10 in Group B (7.81%) (P < 0.05) reported side-effects.

CONCLUSION

We have shown that treatment with SeR-Se-Ly was not inferior to tadalafil 5 mg for improving IPSS and Q_max in men with LUTS.

Non-Adrenergic, Tamsulosin-Insensitive Smooth Muscle Contraction is Sufficient to Replace α1 -Adrenergic Tension in the Human Prostate

BACKGROUND

Lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia may be caused by prostate smooth muscle contraction. Although α₁ -blockers may improve symptoms by prostate smooth muscle relaxation, their efficacy is limited. This may be explained by non-adrenergic mediators causing contraction in parallel to α₁ -adrenoceptors. However, little is known about the relevance and cooperative actions of non-adrenergic mediators in the prostate.

METHODS

Prostate tissues were obtained from radical prostatectomy (n = 127 patients). Contractile responses were studied in an organ bath.

RESULTS

Endothelin-1 and noradrenaline induced contractions of similar magnitude (116 ± 23 and 117 ± 18% of KCl-induced contractions). Endothelin-2- and -3-induced maximum contractions of 63 ± 8.6 and 71 ± 19% of KCl, while contractions by the thromboxane analog U46619 amounted up to 63 ± 9.4%. Dopamine-induced contractions averaged to 22 ± 4.5% of KCl, while maximum contractions by serotonin, histamine, and carbachol stayed below 10% of KCl-induced. While noradrenaline-induced contractions were inhibited by tamsulosin (300 nM), endothelin-1-, -2-, or -3-induced contraction were not. No additive effects were observed if endothelins and noradrenaline were applied consecutively to the same samples. If endothelin-1 was applied after U46619, resulting tension (172 ± 43% of KCl) significantly exceeded noradrenaline-induced contraction. Tensions following combined application of endothelin-2 or -3 with U46619 stayed below noradrenaline-induced contractions. Tension following combined application of all three endothelins with U46619 resembled maximum noradrenaline-induced tone.

CONCLUSIONS

Contractions following concomitant confrontation of human prostate tissue with noradrenaline and endothelin-1 are not additive. Endothelin-1 is sufficient to induce a smooth muscle tone resembling that of noradrenaline. This may replace lacking α₁ -adrenergic tone under therapy with α₁ -blockers, explaining the limited efficacy of α₁ -blockers in LUTS treatment. Contractions by thromboxane and endothelin-1 may be additive, and may exceed α₁ -adrenergic tone. Prostate 77:697-707, 2017. © 2017 Wiley Periodicals, Inc.

Refractory Urinary Incontinence in Girls: The Role of the Bladder Neck

BACKGROUND

Prevalence of lower urinary tract dysfunction (LUTD) in children is between 6 and 9% with urinary incontinence (UI) being one of the most common symptom.

VARIOUS ASPECTS OF LOWER URINARY TRACT SYMPTOMS LUTS

Anatomical anomalies of the urinary tract as well as neurogenic underlying pathology can results in LUTS. Comorbidities and long-term consequences of the LUTD for the female patients as well as genetic issues are also briefly discussed.

THE ROLE OF THE BLADDER NECK

Thanks to urodynamics, we have learnt a lot about the lower urinary tract function, but the role of the bladder neck in the pathophysiology of LUTS in children is not clear. Secondary bladder neck hypertrophy is a well-described pathology, but there is no standardized treatment for this phenomenon. Primary bladder neck dysfunction has already been defined by the International Children's Continence Society.

REFRACTORY UI IN GIRLS

Uniform diagnostic protocols are used in these girls with UI. Treatment consists of standard urotherapy, additional interventions, and pharmacotherapy in selected cases. Those with refractory UI require careful reassessment to look for the unrecognized disorders. Invasive urodynamics should be done in those patients. Ultrasound of the bladder neck region and the pelvic floor can be helpful, but its interpretation is very subjective. In a small group bladder neck insufficiency can be found and those might benefit from a surgical intervention.

FUTURE PERSPECTIVE

Strict criteria of the bladder neck insufficiency in children must be defined. Early surgical intervention in girls with bladder neck insufficiency might reduce the long period of intensive conservative treatment.

[S2e guideline of the German urologists: Conservative and pharmacologic treatment of benign prostatic hyperplasia]

This report summarizes the relevant aspects of the S2e guideline of the German Urologists for the conservative and pharmacological treatment of lower urinary tract symptoms due to benign prostatic hyperplasia. Recommendations are given regarding watchful waiting, behavioral therapy, phytotherapy and pharmacological mono- and combination therapy. The influence of the different therapeutic options on bladder outlet obstruction (BOO) is described in detail.

New therapeutic strategies for the treatment of male lower urinary tract symptoms

Male lower urinary tract symptoms (LUTS) are prevalent in the general population, especially in those of advanced age, and are characterized by notable diversity in etiology and presentation, and have been proven to cause various degrees of impairment on quality of life. The prostate has traditionally been regarded as the core cause of male LUTS. As a result, medical treatment aims to provide symptomatic relief and effective management of progression of male LUTS due to benign prostatic enlargement. In this context, α₁-blockers, phosphodiesterase-5 inhibitors, and 5α-reductase inhibitors have long been used as monotherapies or in combination treatment to control voiding LUTS. There is accumulating evidence, however, that highlights the role of the bladder in the pathogenesis of male LUTS. Current research interests have shifted to bladder disorders, and medical management is aimed at the bladder. Muscarinic receptor antagonists and the newly approved β₃-adrenergic agonist mirabegron aim to alleviate the most bothersome storage LUTS and thus improve quality of life. As voiding and storage LUTS frequently coexist, combination therapeutic strategies with α₁-blockers and antimuscarinics or β₃-agonists have been introduced to manage symptoms effectively. Anti-inflammatory agents, vitamin D₃-receptor analogs, and cannabinoids represent treatment modalities currently under investigation for use in LUTS patients. Furthermore, luteinizing hormone-releasing hormone antagonists, transient receptor-potential channel blockers, purinergic neurotransmission antagonists, Rho-kinase inhibitors, and inhibitors of endothelin-converting enzymes could have therapeutic potential in LUTS management, but still remain in the experimental setting. This article reviews new strategies for the medical treatment of male LUTS, which are dictated by the potential role of the bladder and the risk of benign prostatic hyperplasia progression. Moreover, combination treatments and therapies currently under investigation are also presented.

P21-Activated Kinase Inhibitors FRAX486 and IPA3: Inhibition of Prostate Stromal Cell Growth and Effects on Smooth Muscle Contraction in the Human Prostate

Prostate smooth muscle tone and hyperplastic growth are involved in the pathophysiology and treatment of male lower urinary tract symptoms (LUTS). Available drugs are characterized by limited efficacy. Patients' adherence is particularly low to combination therapies of 5α-reductase inhibitors and α1-adrenoceptor antagonists, which are supposed to target contraction and growth simultaneously. Consequently, molecular etiology of benign prostatic hyperplasia (BPH) and new compounds interfering with smooth muscle contraction or growth in the prostate are of high interest. Here, we studied effects of p21-activated kinase (PAK) inhibitors (FRAX486, IPA3) in hyperplastic human prostate tissues, and in stromal cells (WPMY-1). In hyperplastic prostate tissues, PAK1, -2, -4, and -6 may be constitutively expressed in catecholaminergic neurons, while PAK1 was detected in smooth muscle and WPMY-1 cells. Neurogenic contractions of prostate strips by electric field stimulation were significantly inhibited by high concentrations of FRAX486 (30 μM) or IPA3 (300 μM), while noradrenaline- and phenylephrine-induced contractions were not affected. FRAX486 (30 μM) inhibited endothelin-1- and -2-induced contractions. In WPMY-1 cells, FRAX486 or IPA3 (24 h) induced concentration-dependent (1-10 μM) degeneration of actin filaments. This was paralleled by attenuation of proliferation rate, being observed from 1 to 10 μM FRAX486 or IPA3. Cytotoxicity of FRAX486 and IPA3 in WPMY-1 cells was time- and concentration-dependent. Stimulation of WPMY-1 cells with endothelin-1 or dihydrotestosterone, but not noradrenaline induced PAK phosphorylation, indicating PAK activation by endothelin-1. Thus, PAK inhibitors may inhibit neurogenic and endothelin-induced smooth muscle contractions in the hyperplastic human prostate, and growth of stromal cells. Targeting prostate smooth muscle contraction and stromal growth at once by a single compound is principally possible, at least under experimental conditions.

Solifenacin/tamsulosin fixed-dose combination therapy to treat lower urinary tract symptoms in patients with benign prostatic hyperplasia

Treatment of male lower urinary tract symptoms (LUTS) has traditionally focused on the management of benign prostatic obstruction, but the contribution of bladder dysfunction has been recently recognized. Therefore, it is well understood that LUTS have multifactorial etiology and often occur in clusters and not in isolation. Voiding LUTS are highly prevalent in men, but storage LUTS have been proved to be more bothersome. α₁-Blockers are the most widely used pharmacologic agents for the treatment of symptoms relating to benign prostatic enlargement due to benign prostatic hyperplasia (BPH), while antimuscarinics are the drug class of choice for overactive bladder symptoms. A combination of the two drug classes would be a reasonable approach to treat men with both storage and voiding symptoms, and several short-term studies have proved the efficacy and safety of different combinations with an α₁-blocker and an antimuscarinic. Following previous studies on the separate administration of solifenacin and tamsulosin, a fixed-dose combination tablet of tamsulosin oral controlled absorption system (OCAS) 0.4 mg and solifenacin succinate 6 mg has been recently introduced, and the current review evaluates the available data on the use of this fixed-dose combination in the treatment of LUTS in men with BPH.

Inhibition of smooth muscle force generation by focal adhesion kinase inhibitors in the hyperplastic human prostate

Smooth muscle contraction may be critical for lower urinary tract symptoms (LUTS) in patients with benign prostate hyperplasia and requires stable anchorage of the cytoskeleton to the cell membrane. These connections are regulated by focal adhesion kinase (FAK). Here, we addressed the involvement of FAK in the regulation of smooth muscle contraction in hyperplastic human prostate tissues. Prostate tissues were obtained from radical prostatectomy. Expression of FAK and focal adhesion proteins was assessed by Western blot analysis and immunohistochemical stainings. Effects of the FAK inhibitors PF-573228 and Y-11 on contraction of prostate strips were examined in the organ bath. Expression of FAK and focal adhesion proteins (integrin-5α, paxilin, and c-Src) was detected by Western blot analysis in prostate samples. By double immunofluorescence staining with calponin and pan-cytokeratin, expression of FAK was observed in stromal and epithelial cells. Immunoreactivity for FAK colocalized with integrin-5α, paxilin, talin, and c-Src. Stimulation of prostate tissues with the α1-adrenergic agonist phenylephrine increased the phosphorylation state of FAK at Tyr397 and Tyr925 with different kinetics, which was blocked by the α1-adrenoceptor antagonist tamsulosin. Norepinephrine and phenylephrine induced concentration-dependent contractions of prostate strips. Both FAK inhibitors PF-573228 and Y-11 significantly inhibited norepinephrine- and phenylephrine-induced contractions. Finally, PF-573228 and Y-11 inhibited contractions induced by electric field stimulation, which was significant at the highest frequency. In conclusion, α1-adrenergic smooth muscle contraction or its regulation involves FAK in the human prostate. Consequently, FAK may be involved in the pathophysiology of LUTS and in current or future LUTS therapies.

Neurological status predicts response to alpha-blockers in men with voiding dysfunction and Parkinson's disease

OBJECTIVES

To evaluate predictors of the response to doxazosin, a selective alpha-adrenoceptor antagonist, when used for the treatment of lower urinary tract symptoms in men with Parkinson's disease.

METHODS

In a prospective study, 33 consecutive men (mean age 59.2 ± 7.0 years) with Parkinson's disease and lower urinary tract symptoms were evaluated. Neurological dysfunction was assessed with the Unified Parkinson's Disease Rating Scale. Urological assessment was performed at baseline and after 12 weeks of treatment with 4 mg/day of extended-release doxazosin, including symptom evaluation with the International Continence Society male short-form questionnaire, an assessment of the impact of lower urinary tract symptoms on quality of life and urodynamics. Clinical and urodynamic predictors of response were specifically evaluated.

RESULTS

Compared with the score at baseline, the total International Continence Society male short-form score was reduced after doxazosin administration, from 17.4 ± 7.5 to 11.1 ± 6.9 (p<0.001). The impact of lower urinary tract symptoms on quality of life was also significantly reduced, from 1.8 ± 1.1 to 1.0 ± 1.0 (p<0.001) and the maximum urinary flow varied from 9.3 ± 4.4 to 11.2 ± 4.6 ml/s (p=0.025). The severity of neurological impairment was the only predictor of the clinical response. Additionally, patients with a Unified Parkinson's Disease Rating Scale score lower than 70 had a significantly higher chance of clinical improvement with doxazosin treatment than those with higher Unified Parkinson's Disease Rating Scale scores did (RR=3.10, 95% CI=[1.15 to 5.37], p=0.011).

CONCLUSIONS

Doxazosin resulted in the improvement of lower urinary tract symptoms and the maximum flow rate and was well tolerated in men with Parkinson's disease. The response to treatment is dependent on the severity of neurological disability.

Antimuscarinics and α-blockers or α-blockers monotherapy on lower urinary tract symptoms--a meta-analysis

OBJECTIVE

To assess the clinical efficiency and safety of combination pharmacotherapy of antimuscarinics and α-blockers vs α-blockers monotherapy on patients with moderate to severe lower urinary tract symptoms (LUTS).

METHODS

We searched the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, the Cochrane Database of Systematic Review, and Web of Science from their inception until June 2013 to identify all eligible studies that compare the 2 pharmacotherapy strategies on LUTS. The Cochrane Collaboration's RevMan 5.2 software was used for data analysis, and the fixed or the random effect model was selected depending on the proportion of heterogeneity.

RESULTS

Eighteen eligible randomized controlled trials were included in this systematic review, including 2106 (51.57%) in cotherapy group and 1978 (48.43%) in monotherapy group. Synthetic data showed that there were significant improvements on Storage International Prostate Symptom Score (mean difference [MD] = -1.51; 95% confidence interval [CI] -2.10 to -0.91, P <.00001), quality of life score (MD = -0.53; 95% CI -0.89 to -0.17, P = .004), micturitions per 24 hours (MD = -1.14; 95% CI -1.84 to -0.45, P = .001), and urgency episodes per 24 hours (MD = -0.99; 95% CI -1.46 to -0.51, P <.0001) in the cotherapy group. There were no significant difference regarding maximum flow rate (MD = -0.05; 95% CI -0.27 to 0.17, P = .64), Total International Prostate Symptom Score (TIPSS) (MD = -0.88; 95% CI -1.64 to -0.12, P = .02), and Voiding International Prostate Symptom Score (VIPSS) (MD = 0.40; 95% CI -0.34 to 1.15, P = .29). As to postvoid residual volume, however, a worse condition was showed in the cotherapy group (MD = -6.53; 95% CI 3.06-10.00, P <.0002).

CONCLUSION

Antimuscarinics could and should be added to the drug regimen for patients with LUTS attributed to benign prostatic hyperplasia/bladder outlet obstruction, particularly are dominated by storage symptoms. For patients with increased acute urinary retention risk, they should be carefully monitored.

Effects of silodosin, a selective α1A-adrenoceptor antagonist, on bladder blood flow and bladder function in a rat model of atherosclerosis induced chronic bladder ischemia without bladder outlet obstruction

PURPOSE

We investigated the effects of the selective α1A-adrenoceptor antagonist silodosin on bladder blood flow and bladder function in a rat model of atherosclerosis induced chronic bladder ischemia without bladder outlet obstruction.

MATERIALS AND METHODS

The chronic bladder ischemia model was prepared by creating balloon endothelial injury of the bilateral iliac arteries in male rats. Using an osmotic pump, chronic bladder ischemia rats received silodosin subcutaneously at a rate of 0.1 or 0.3 mg/kg per day, or vehicle for 8 weeks. All groups received a 2% cholesterol diet throughout the experiment. For each α1-adrenoceptor subtype mRNA expression in bladder microvessels was examined by in situ hybridization. Bladder blood flow was measured using a laser speckle blood flow imager. Malondialdehyde in bladder tissue and 8-hydroxy-2'-deoxyguanosine in urine were measured as markers of oxidative stress. A metabolic cage study and cystometry were performed in conscious rats.

RESULTS

The expression of all α1-adrenoceptor subtype mRNA was observed in rat bladder microvessels. Silodosin abrogated the decreased bladder blood flow in the empty bladder and during bladder distention that were evident in rats with chronic bladder ischemia. Levels of oxidative stress markers in these rats were significantly decreased by silodosin administration. Silodosin ameliorated bladder dysfunction in rats with chronic bladder ischemia in the metabolic cage study and on cystometry.

CONCLUSIONS

Results suggest that in ischemic conditions α1-adrenoceptor antagonists such as silodosin may improve bladder function by restoring bladder blood flow.

[Medical therapy of lower urinary tract symptoms [corrected]]

Male lower urinary tract symptoms (LUTS) include storage and voiding disorders and should be carefully evaluated before the start of any treatment. Medical therapy is directed at improving symptoms and reducing the risk of progression in order to improve quality of life and prevent complications, such as acute urinary retention, or the need for surgical intervention. Careful assessment of the individual complaints helps to identify the best drug which should be adapted to each individual patient's risk profile. At present, α(1)-adrenoreceptor inhibitors and 5-alpha reductase inhibitors and their combination form the gold standard for pharmacological treatment. In addition, anticholinergic agents are increasingly being used as monotherapy or in combination with α1-adrenocepetor inhibitors for patients with predominant storage disorders while phosphodiesterase 5 (PDE5) inhibitors may be suitable for patients suffering from LUTS and concomitant erectile dysfunction.

Benign prostatic hyperplasia

Male Lower Urinary Tract symptoms (LUTs) and Benign Prostatic Hyperplasia (BPH) provide a significant proportion of the core urologists workload, and will continue to do so for the foreseeable future with an increasingly elderly population. This review sets out to provide an overview of the current understanding around BPH and male LUTs as well as investigations and treatment options.

Cataract surgery in patients taking alpha-1 antagonists: know the risks, avoid the complications

BACKGROUND

The growing use of alpha-1 receptor antagonists in the treatment of benign prostatic hyperplasia (BPH) has created a new problem in ophthalmic surgery, the so-called intraoperative floppy iris syndrome (IFIS). This consists of a billowing iris, insufficient pupillary dilation with progressive intraoperative miosis, and protrusion of iris tissue through the tunnel and side port incision that are made for access to the anterior chamber during surgery. IFIS presents particular difficulties in cataract surgery which is carried out through the pupil with manipulations in the immediate vicinity of the iris. The complications range from poor visibility of the operative field to iris damage with the surgical instruments and to rupture of the posterior capsule, with loss of lens material into the vitreous body.

METHODS

Selective literature review.

RESULTS

Alpha-blockers have a direct effect on the alpha-receptors of the iris but also induce ultrastructural changes in the iridial stroma, leading to IFIS. The most important factor in avoiding complications of IFIS seems to be the ophthalmic surgeon's knowledge that the patient is taking an alpha-1 receptor antagonist.

CONCLUSION

A thorough medical history and an optimized information flow among all physicians treating the patient-the urologist, the family physician, and the ophthalmic surgeon-are essential for safe cataract surgery.

Emerging treatment options for benign prostatic obstruction

Benign prostatic obstruction (BPO) affects an increasing number of men with age. It can cause troublesome lower urinary tract symptoms, can have a negative impact on quality of life, and may be associated with significant morbidity. Currently available medication and surgical treatments are limited by adverse events, invasiveness, and patient compliance. This has driven research into the pathogenesis of benign prostatic hyperplasia and led to the development of novel pharmacological agents and minimally invasive therapeutic interventions. This review highlights emerging treatment options for BPO.

The effect of alpha-blocker treatment on bladder hypoxia inducible factor-1 alpha regulation during lower urinary tract obstruction

AIMS

To determine whether alpha1-blocker treatment, in chronic bladder outlet obstruction (BOO), influences bladder tissue ischemia.

MATERIALS AND METHODS

This prospective study included 60 patients with BOO, of which 40 were under alpha1-blocker medication and 20 without treatment. Patients underwent transurethral resection of the prostate (TURP) or suprapubic prostatectomy (SPP). Ten patients with non-muscle invasive bladder cancer underwent transurethral resection of the bladder tumor and served as the control group. Tissue specimens were immunohistochemically stained for hypoxia inducible factor-1alpha (HIF-1alpha).

RESULTS

Bladder tissue from obstructed subjects showed high immunoreactivity to HIF-1alpha. The specimens from the control group, showed no or weak, mainly cytoplasmic immunoreactivity to HIF-1alpha. Patients under alpha -blocker treatment did not differ in the number of HIF-1alpha positive cells compared to subjects with no treatment (median number 86.8 [20-150] and 88.6 [0-175], respectively) (p > 0.05). The lowest bladder pressure at which HIF-1alpha was up regulated, was detected at detrusor pressure Qmax (PdetQmax) = 60 cm H2O.

CONCLUSIONS

Treatment with alpha-blockers in obstructed patients considered as non-responders, does not result in HIF-1alpha down regulation, thus bladder continues to be under chronic stress.

The forefront for novel therapeutic agents based on the pathophysiology of lower urinary tract dysfunction: alpha-blockers in the treatment of male voiding dysfunction - how do they work and why do they differ in tolerability?

alpha(1)-Adrenoceptor antagonists are the mainstay of medical treatment of male voiding dysfunction which typically is attributed to benign prostatic hyperplasia. While original concepts have assumed that they relieve voiding dysfunction by relaxing prostatic smooth muscle, newer data indicate that their therapeutic effects at least partly occur independent of prostatic relaxation, perhaps involving direct effects on blood vessels, urothelium, afferent nerves, and/or smooth muscle of the urinary bladder. The adverse event profiles differ among alpha(1)-adrenoceptor antagonists, with tamsulosin having a particularly good cardiovascular tolerability. While this was originally attributed to its selectivity for alpha(1A)-adrenoceptors, it appears that alfuzosin which lacks subtype-selectivity, has a very similar tolerability. In contrast, doxazosin and terazosin, which are chemically and pharmacologically more closely related to alfuzosin than to tamsulosin, appear to have more side effects attributable to the cardiovascular system. More recent data indicate that tolerability differences between alpha(1)-adrenoceptor antagonists may at least partly relate to pharmacokinetic rather than to pharmacodynamic differences. Taken together, these data emphasize the idea that concepts about drug efficacy and tolerability despite being highly plausible may not necessarily be true and always require thorough experimental testing.

The effect of bladder outlet obstruction on alpha1- and beta-adrenoceptor expression and function

AIMS

To explore possible changes in expression and/or function of alpha(1)- and beta-adrenoceptor subtypes as a cause for bladder dysfunction in a rat model of bladder outlet obstruction (BOO).

METHODS

BOO was induced in rats by partial urethral ligature. Contraction and relaxation experiments were performed with isolated bladder strips from BOO, sham-operated and non-operated (control) rats 7 days after BOO induction. mRNA expression of alpha(1)- and beta-adrenoceptor subtypes was assessed by quantitative real-time PCR.

RESULTS

Receptor-independent contraction or relaxation did not differ between BOO and sham rats. The alpha(1)-agonists methoxamine and A-61,603 caused only weak contraction without major differences between groups. Against KCl-induced tone, the beta-adrenoceptor agonists noradrenaline and isoprenaline caused similar relaxation in BOO and sham rats, whereas relaxation in response to the beta(3)-selective BRL 37,344 was attenuated. Against passive tension, noradrenaline induced relaxation in sham and control rats; in contrast, noradrenaline induced contraction at low concentrations and relaxation at high concentrations in BOO rats. The contraction component was abolished by the alpha(1)-antagonist prazosin. The mRNA expression of alpha(1D)-adrenoceptors was increased in BOO, whereas none of the other receptor mRNAs were up-regulated.

CONCLUSIONS

In a rat BOO model, weak contraction responses to alpha(1)-agonists and relaxation responses to beta-agonists are not altered to a major extent. Nevertheless, relaxation responses to the endogenous agonist noradrenaline are turned into alpha(1)-adrenoceptor-mediated contraction responses in BOO, possibly due to an up-regulation of alpha(1D)-adrenoceptors.

[Treatment of LUTS in BPS. When and when not to administer pills?]

Benign prostatic syndrome (BPS) is considered a diagnosis of exclusion and needs a thorough work-up. One of the pitfalls for a tailored medical treatment scheme is the objective evaluation of benign prostatic obstruction. Characteristics of the various medical therapy options and the multifactorial origin of LUTS in BPH patients imply an individualized approach. LUTS involving mostly urine storage disorders and a small prostate are suitably managed with alpha(1)-receptor antagonists, which may be combined with antimuscarinics if OAB symptoms predominate. Long-term treatment addressing clinical progression may favor combination therapy of alpha(1)-receptor antagonists with 5alpha-reductase inhibitors if prostate size is sufficient. Age, symptom severity at baseline, a large prostate volume, or a high PSA value are indicative of progression. However, combination therapy aggravates side effects, and thus a risk-benefit analysis is essential. The potential of any medication for BPS to treat obstruction is rather low. If deobstruction is the main aim of therapy, medical treatment is not suitable.

Do α1-adrenoceptor antagonists improve lower urinary tract symptoms by reducing bladder outlet resistance?

AIMS

To test the hypothesis that improvements of lower urinary tract symptoms (IPSS) upon treatment with an alpha-blocker are due to reduction of bladder outlet obstruction (assessed as the bladder outlet obstruction index, BOOI); relationships of either with free flow Q(max) were also explored.

METHODS

The database of a large placebo-controlled, randomized, double-blind study with the alpha-blocker tamsulosin was analyzed retrospectively. Patients were stratified into lower and upper halves according to baseline IPSS, Q(max) or BOOI and treatment-associated alterations thereof. In these strata differences between values for the other two parameters were analyzed, for example, improvement of IPSS and Q(max) were compared in patients with below and above median improvement of BOOI.

RESULTS

Patients with below and above median baseline for one parameter, for example, IPSS had rather similar values for the other two parameters, for example, Q(max) and BOOI. Likewise, patients based upon baseline strata for one parameter had rather similar improvements of the other two parameters. Most importantly, patients with below and above median treatment-associated improvements of one parameter, for example, BOOI exhibited only small if any difference for alterations of the other two parameters, for example, IPPS and Q(max).

CONCLUSIONS

We conclude that IPSS, free flow Q(max) and BOOI are only loosely related at baseline. More importantly, treatment-induced improvements of these parameters are also only loosely related. These data do question the hypothesis that alpha-blockers largely improve lower urinary tract symptoms by reducing bladder outlet obstruction and suggest that they may also act independent of prostatic smooth muscle tone.

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

1 We have systematically reviewed the presence, functional responses and regulation of alpha(1)-, alpha(2)- and beta-adrenoceptors in the bladder, urethra and prostate, with special emphasis on human tissues and receptor subtypes. 2 Alpha(1)-adrenoceptors are only poorly expressed and play a limited functional role in the detrusor. Alpha(1)-adrenoceptors, particularly their alpha(1A)-subtype, show a more pronounced expression and promote contraction of the bladder neck, urethra and prostate to enhance bladder outlet resistance, particularly in elderly men with enlarged prostates. Alpha(1)-adrenoceptor agonists are important in the treatment of symptoms of benign prostatic hyperplasia, but their beneficial effects may involve receptors within and outside the prostate. 3 Alpha(2)-adrenoceptors, mainly their alpha(2A)-subtype, are expressed in bladder, urethra and prostate. They mediate pre-junctional inhibition of neurotransmitter release and also a weak contractile effect in the urethra of some species, but not humans. Their overall post-junctional function in the lower urinary tract remains largely unclear. 4 Beta-adrenoceptors mediate relaxation of smooth muscle in the bladder, urethra and prostate. The available tools have limited the unequivocal identification of receptor subtypes at the protein and functional levels, but it appears that the beta(3)- and beta(2)-subtypes are important in the human bladder and urethra, respectively. Beta(3)-adrenoceptor agonists are promising drug candidates for the treatment of the overactive bladder. 5 We propose that the overall function of adrenoceptors in the lower urinary tract is to promote urinary continence. Further elucidation of the functional roles of their subtypes will help a better understanding of voiding dysfunction and its treatment.