Chronic ischemia increases prostatic smooth muscle contraction in the rabbit

Molecular Regulation of Concomitant Lower Urinary Tract Symptoms and Erectile Dysfunction in Pelvic Ischemia

Aging correlates with greater incidence of lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) in the male population where the pathophysiological link remains elusive. The incidence of LUTS and ED correlates with the prevalence of vascular risk factors, implying potential role of arterial disorders in concomitant development of the two conditions. Human studies have revealed lower bladder and prostate blood flow in patients with LUTS suggesting that the severity of LUTS and ED correlates with the severity of vascular disorders. A close link between increased prostatic vascular resistance and greater incidence of LUTS and ED has been documented. Experimental models of atherosclerosis-induced chronic pelvic ischemia (CPI) showed increased contractile reactivity of prostatic and bladder tissues, impairment of penile erectile tissue relaxation, and simultaneous development of detrusor overactivity and ED. In the bladder, short-term ischemia caused overactive contractions while prolonged ischemia provoked degenerative responses and led to underactivity. CPI compromised structural integrity of the bladder, prostatic, and penile erectile tissues. Downstream molecular mechanisms appear to involve cellular stress and survival signaling, receptor modifications, upregulation of cytokines, and impairment of the nitric oxide pathway in cavernosal tissue. These observations may suggest pelvic ischemia as an important contributing factor in LUTS-associated ED. The aim of this narrative review is to discuss the current evidence on CPI as a possible etiologic mechanism underlying LUTS-associated ED.

Comparison of Tamsulosin and Tadalafil effects in LUTS treatment considering patients' atherosclerosis risk level

Introduction

To date, no study evaluates the effect of atherosclerosis risk level on the efficacy of BPH drug therapies. Therefore, the present study aimed to assess the effect of atherosclerosis risk levels on the effectiveness of Tamsulosin and Tadalafil in LUTS treatment.

Methods

The present study was a randomized clinical trial that assessed men with LUTS symptoms (at least six months). The inclusion criteria were being older than 50 years, international prostate symptom score (IPSS) ≥ 13, and maximum urinary flow rate (Qmax) between 4 and 15 ml/s. Framingham Risk Score was used to measure atherosclerosis risk. The patients were classified into four groups, including group 1: Patients with low risk and treated with Tamsulosin (0.4 mg/day), group 2: Patients with low risk and treated with Tadalafil (5 mg/day), group 3: Patients with high risk and treated with Tamsulosin (0.4 mg/day), group 4: Patients with high risk and treated with Tadalafil (5 mg/day).

Results

The study included 44 and 38 patients receiving Tamsulosin and Tadalafil, respectively. The means (SD) of the baseline age for the Tamsulosin and Tadalafil groups were equal to 60.6 (6.8) and 58.8 (6.7), respectively (p-value = 0.213). The models revealed no impact of the atherosclerosis risk level on the drugs' effects (p-values = 0.378, 0.975, 0.743 for IPSS, QMAX, and VOID, respectively).

Conclusions

The present study's findings could not show the impact of atherosclerosis risk levels on the efficiency of Tamsolusin and Tadalafil in men with LUTS.

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Assessing the impact of atherosclerosis risk level on the effectiveness of Tamsulosin and Tadalafil in LUTS treatment.

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The present study's findings could not show the impact of atherosclerosis risk level on the efficiency of Tamsulosin and Tadalafil in men with LUTS.

Association of Overactive Bladder With Hypertension and Blood Pressure Control: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

The sudden urge to urinate, also known as overactive bladder (OAB), may reflect higher sympathetic activity and associate with higher blood pressure (BP).

METHODS

This cross-sectional analysis utilized data from sixth follow-up exam (2015-2016) of Multi-Ethnic Study of Atherosclerosis to examine the association of OAB with systolic (SBP) and diastolic blood pressure (DBP) levels, hypertension, and BP control. Information on urinary symptoms was obtained with the International Consultation on Incontinence Questionnaire (ICIQ). Sex-stratified regression models were constructed to examine differences in BP, hypertension prevalence, and BP control while adjusting for demographic factors, comorbidities, and medication use.

RESULTS

Among the 1,446 men and 1,628 women who completed the ICIQ (mean age 73.7 years [SD 8.4]), OAB was present in 31.6% of men and 38.9% of women. With no antihypertensive medication use, OAB was not associated with SBP or DBP in both men and women after adjusting for covariates. However, among the 894 men and 981 women on antihypertensive medication, OAB was associated with higher SBP among men (4.04 mm Hg; 95% confidence interval [CI] 1.02, 7.06) but not among women (-0.67 mm Hg; 95% CI -3.79, 2.46) while DBP did not differ by OAB presence in men or women. In addition, OAB was also associated with lower odds of BP control among men (odds ratio [OR] 0.69; 95% CI 0.49, 0.96) but not women (OR 0.96; 95% CI 0.71, 1.30).

CONCLUSIONS

Among men, OAB is associated with lower odds of BP control which suggests that OAB may impede hypertension management.

The effect of pharmacotherapy on prostate volume, prostate perfusion and prostate-specific antigen (prostate morphometric parameters) in patients with lower urinary tract symptoms and benign prostatic obstruction. A systematic review and meta-analysis

Introduction

The clinical effect of pharmacotherapy on prostate morphometric parameters is largely unknown. The sole exception is 5α-reductase inhibitors (5-ARI) that reduce prostate volume and prostate-specific antigen (PSA). This review assesses the effect of pharmacotherapy on prostate parameters effect on prostate parameters, namely total prostate volume (TPV), transitional zone volume (TZV), PSA and prostate perfusion.

Material and methods

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) reporting on morphometric parameters’ changes after pharmacotherapy, as primary or secondary outcomes. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. RCTs’ quality was assessed by the Cochrane tool and the criteria of the Agency for Healthcare Research and Quality. The effect magnitude was expressed as standard mean difference (SMD). The study protocol was published on PROSPERO (CRD42020170172).

Results

Sixty-seven RCTs were included in the review and 18 in the meta-analysis. The changes after alpha-blockers are comparable to placebo. Long-term studies reporting significant changes from baseline, result from physiologic growth. Finasteride and dutasteride demonstrated large effect sizes in TPV reduction ([SMD]: -1.15 (95% CI: -1.26 to -1.04, p <0.001, and [SMD]:-0.66 (95% CI: -0.83 to -0.49, p <0.001, respectively), and similar PSA reductions. Dutasteride’s effect appears earlier (1^st vs 3^rd month), the changes reach a maximum at month 12 and are sustained thereafter. Phosphodiesterase-5 (PDE-5) inhibitors have no effect on morphometric parameters. Phytotherapy’s effect on TPV is non-significant [SMD]: 0.12 (95% CI: -0.03 to 0.27, p = 0.13). Atorvastatin reduces TPV as compared to placebo (-11.7% vs +2.5%, p <0.01). Co-administration of testosterone with dutasteride spares the prostate from the androgenic stimulation as both TPV and PSA are reduced significantly.

Conclusions

The 5-ARIs show large effect size in reducing TPV and PSA. Tamsulosin improves perfusion but no other effect is evident. PDE-5 inhibitors and phytotherapy do not affect morphometric parameters. Atorvastatin reduces TPV and PSA as opposed to testosterone supplementation.

The influence of prostatic calculi on lower urinary tract symptoms and sexual dysfunction: a narrative review

Prostatic calculi (PC) are commonly found in patients who present for urologic consultation. However, the effect of PC on urinary symptoms remains controversial. In this study, we searched the Embase and PubMed databases for literature related to the following keywords: “prostatic calculi”, “prostatic stone”, “prostatic lithiasis” and “prostatic calcification”, along with the limits, “lower urinary tract symptoms”, “sexual dysfunction”, “erectile dysfunction”, “erectile function”, and “premature ejaculation”. According to the literature, there are various subtypes of PC based on X-ray or ultrasound findings, including type I/II, type A/B, and endogenous PC/extrinsic PC. Furthermore, the formation of PC remains unclear, and more importantly, the ability of PC to cause lower urinary tract symptoms (LUTS) and sexual dysfunction (SD) is worth exploring. We retrospectively reviewed all available literature and found that most studies agreed that PC are associated with LUTS. The factors which may play an important role in the pathogenesis of LUTS include the size and location of PC, induced inflammation, and the blood flow of the prostate. Similarly, SD was also examined in the patients with PC, and psychological factors cannot be ignored in this regard. However, more in-depth study of the molecular mechanisms, including prospective, controlled, longitudinal, and large- sample studies, are needed in the future.

Bladder sensation evaluation of a carrageenan-induced chronic prostatitis model using a direct measurement of the bladder mechanosensitive single-unit afferent nerve activity

AIMS

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) causes long-standing pain and/or storage symptoms. This study aimed to evaluate the likelihood of deterioration of bladder sensation in a carrageenan-induced CP/CPPS model by direct measurement of the bladder mechanosensitive single-unit afferent nerve activity.

METHODS

In this study, male adult Sprague-Dawley rats were used. They were injected 50 µL of 3% λ-carrageenan or its vehicle (saline) into both lobes of the ventral prostate. Seven days following injection, the pain behavior at the pelvic-perineal area (using von Frey filaments), prostatic blood flow (using a laser blood flowmeter), and histology were examined along with cystometry (under conscious free-moving condition) and mechanosensitive single-unit afferent nerve activity (under urethane anesthesia).

RESULTS

The prostate showed increased tissue weight and decreased blood flow and inflammatory cell infiltration in the carrageenan group compared to the control group. Consequently, the threshold of the pain behavior was decreased, and the basal and threshold pressures of the bladder were increased in the carrageenan group. In contrast, no significant differences of bladder histology and other cystometric parameters were found between the groups. Regarding Aδ- or C-fibers, the mechanosensitive afferent nerve activities revealed no differences in either group.

CONCLUSIONS

The carrageenan-induced CP/CPPS rat model showed edema, ischemia, and inflammatory pain in the prostate, whereas a little change was detected in bladder sensation. These findings, which were evaluated using a direct measurement of the mechanosensitive single-unit afferent nerve activity, suggest that the bladder sensation is unlikely deteriorated in this model.

Immunohistochemical analysis of the impact of ischemic change in benign prostatic hyperplasia

OBJECTIVE

We conducted experiments to elucidate the impact of ischemic change on benign prostatic hyperplasia (BPH) using immunohistochemistry.

METHODS

Medical records of consecutive patients over 60 years of age who underwent transurethral resection of the prostate for BPH between January 2009 and September 2012 were evaluated. As vascular risk factors, the presence or absence of diabetes mellitus, hypertension, current smoking, obesity, dyslipidemia, and diseases related to bladder function were investigated. As BPH-related factors, International Prostate Symptom Score, quality of life, maximal flow rate, postvoid residual volume, prostate-specific antigen, prostate volume, prostate calculi, and medication state for BPH were investigated. Immunohistochemistry was performed for hypoxia-inducible factor (HIF-1α), sex hormone receptors, and smooth muscle actin. Additionally, microvessel density (MVD) and diffuse fibrosis (DF) were evaluated.

RESULTS

A total of 101 patients were included and HIF-1α expression in stroma and glands were observed in 56 (55.4%) and 34 (33.7%) cases, respectively. There was no significant association between HIF-1α expression and vascular risk factors or BPH-related variables. However, there was a significant correlation between the HIF-1α expression in stroma and higher MVD. HIF-1α expression in the stroma was also significantly correlated with higher expressions of the androgen and progesterone receptors in the stroma. DF was frequently found in cases with higher HIF-1α expression in the stroma than in those with lower HIF-1α expression.

CONCLUSION

In patients with response to ischemic changes of the prostate, HIF-1α expression could be confirmed, and the expression of the androgen receptor was significantly lower in these patients. Chronic ischemic damage in the prostate can progress to a condition that is refractory to pharmacologic therapy. Chronic ischemic damage, which can progress to refractory phase to pharmacologic therapy, is correlated with the hormonal status of prostate.

[Prostatic blood flow as prominent targets on benign prostatic hyperplasia]

Benign prostatic hyperplasia/benign prostatic enlargement (BPH/BPE) is a common proliferative disease, and giving rise to associate with lower urinary tract symptoms (LUTS). However, the pathogenesis is not well clarified, and thought to be multifactorial. There are some lines of evidence that impairment in the blood supply of the lower urinary tract causes development of BPH/BPE. Clinical data showed an association between the development of BPH/BPE and atherosclerotic disease such as hypertension, diabetes and hyperlipidemia. The spontaneously hypertensive rat (SHR) has been used as model of genetic hypertension. SHR also shows decreased blood flow and hyperplastic morphological abnormalities in the ventral prostate. Our previous studies demonstrated that chronic treatment with vasodilative drugs nicorandil (ATP sensitive potassium channel opener) and silodosin (alpha1 adrenoceptor antagonist) increased blood flow and suppressed the growth factor and morphological abnormalities in the SHR ventral prostate. These data suggested that prostatic blood flow could be therapeutic targets for BPH/LUTS.

Lower urinary tract symptoms/benign prostatic hyperplasia and erectile dysfunction: from physiology to clinical aspects

Erectile dysfunction, prostatic hyperplasia and lower urinary tract symptoms hare important pathogenetic links. Endothelial dysfunction and hormonal alterations represent the main aspects. The present article examines the anatomical, physiological, and pathophysiological characteristics of this association, finalizing the text to an interpretation of the clinical management of these patients based on these functional considerations.

Penile blood pressure is useful to identify candidates for tadalafil treatment in patients with lower urinary tract symptoms

OBJECTIVES

To determine whether penile blood pressure (PBP) can be used to identify patients who can benefit from tadalafil treatment, the correlation between PBP at baseline and changes in lower urinary tract symptoms (LUTS) induced by tadalafil treatment was studied prospectively.

PATIENTS AND METHODS

Patients with BPH who were poor responders to α₁ -blockers and took tadalafil instead of an α₁ -blocker were registered between 2014 and 2016. The patients were divided into two groups (low- and high-PBP groups) using the median baseline PBP of 110 mmHg as the threshold. The changes in the International Prostate Symptom Score (IPSS) between before and at 4 and 12 weeks after tadalafil treatment were compared between the low- and high-PBP groups. Multivariate analysis was performed to identify parameters associated with IPSS improvement with tadalafil treatment.

RESULTS

In all, 51 patients were investigated. The IPSS in the low-PBP group decreased immediately after the start of treatment, and there was significant improvement in the IPSS from baseline at 4 and 12 weeks after the start of treatment, whilst the IPSS in the high-PBP group did not show significant changes. On multivariate analysis, PBP at baseline, anticholinergic drug use, and IPSS at baseline were significant predictors of a good IPSS response to tadalafil treatment.

CONCLUSIONS

This study demonstrated that PBP could reliably identify patients with BPH who could benefit from tadalafil treatment. Patients with low PBP could be better responders to tadalafil.

Prostatitis Syndromes and Sporting Activities

Introduction

Prostatitis-like syndromes are high prevalent health problems and frequently considered by patients and physicians as strictly correlated to sports causing perineal compression. These syndromes and their relationships with sporting activities have been discussed in this report.

Methods

We reviewed peer-reviewed scientific articles published by May 2009 and searched according to the following term selection: prostatitis, pudendal nerve, sport, cycling.

Results

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a major healthcare burden heavily affecting patients’ Quality of Life. No clear evidence of any direct etiologic relationship has been found in literature between prostatitis, either bacterial or non-bacterial, and sports activities. On the other hand, some types of sport causing perineal compression, such as cycling, can exacerbate symptoms of acute and chronic prostatitis; a temporary sport discontinuation is justified in these patients. CP/CPPS may be often caused by pudendal nerve entrapment (PNE). Prostatitis-like urogenital neuropathic pain together with voiding and sexual dysfunctions are the hallmark of PNE. A common feature is that flexion activities of the hip, such as climbing, squatting, cycling provoke or worsen urogenital pain or pelvic pain. Many of the patients with PNE are cyclists, played American football, lifted weights, or wrestled as teenagers and young adults. PNE represents the most common bicycling associated urogenital problems.

Conclusions

Overall, studies show that no causal relationship has been demonstrated between prostatitis and sporting activities. Conversely, urologists should be aware that sports involving vigorous hip flexion activities or prolonged perineal compression are a potential and not an infrequent cause of uroand rological symptoms caused by pudendal nerve entrapment.

Association of Prostate Blood Flow with Male Lower Urinary Tract Symptoms

PURPOSE

To investigate the association of prostate blood flow (PBF) with lower urinary tract symptoms (LUTS) in aged males using Doppler spectral waveform (DSW) analysis.

PATIENTS AND METHODS

We performed a prospective analysis involving 133 aged males with clinical diagnosis of LUTS. DSW parameters (peak-systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI)) were measured at bilateral neurovascular bundles (NVB), periurethral, and capsular branches by Doppler transrectal ultrasound with the patient in the right lateral decubitus position. The associations of PBF parameters and the International Prostate Symptom Score (IPSS) were analyzed.

RESULTS

Overall, total IPSS scores were significantly correlated with the RI of bilateral NVB vessels (r2 = 0.03, 0.04; p = 0.04, 0.02, respectively), and PSV of left NVB vessels. PSV of bilateral NVB vessels were associated with the storage score (p = 0.022 and p = 0.016), but not with the voiding score. The sum of the frequency and urgency score was also associated with EDV of both capsular and urethral branches (p = 0.043 and p = 0.009, respectively), and PSV of NVB vessels on both sides (p = 0.045 and p = 0.019, respectively).

CONCLUSIONS

There is an association between PBF and LUTS, especially with storage symptoms. The findings may provide some insights in understanding the underlying pathophysiology of lower urinary tract dysfunction.

New medical treatments for lower urinary tract symptoms due to benign prostatic hyperplasia and future perspectives

BACKGROUND

Lower Urinary Tract Symptoms (LUTS) in men are a common clinical problem in urology and have been historically strictly linked to benign prostatic hyperplasia (BPH), which may lead to bladder outlet obstruction (BOO). New molecules have been approved and have entered the urologists' armamentarium, targeting new signaling pathways and tackling specific aspects of LUTS. Objective of this review is to summarize the evidence regarding the new medical therapies currently available for male non-neurogenic LUTS, including superselective α1-antagonists, PDE-5 inhibitors, anticholinergic drugs and intraprostatic onabotulinum toxin injections.

METHODS

The National Library of Medicine Database was searched for relevant articles published between January 2006 and December 2015, including the combination of "BPH", "LUTS", "medical" and "new". Each article's title, abstract and text were reviewed for their appropriateness and their relevance. One hundred forty eight articles were reviewed.

RESULTS

Of the 148 articles reviewed, 92 were excluded. Silodosin may be considered a valid alternative to non-selective α1-antagonists, especially in the older patients where blood pressure alterations may determine major clinical problems and ejaculatory alterations may be not truly bothersome. Tadalafil 5 mg causes a significant decrease of IPSS score with an amelioration of patients' QoL, although with no significant increase in Qmax. Antimuscarinic drugs are effective on storage symptoms but should be used with caution in patients with elevated post-void residual. Intraprostatic injections of botulinum toxin are well-tolerated and effective, with a low rate of adverse events; however profound ameliorations were seen also in the sham arms of RCTs evaluating intraprostatic injections.

CONCLUSION

New drugs have been approved in the last years in the medical treatment of BPH-related LUTS. Practicing urologists should be familair with their pharmacodynamics and pharmacokinetics.

LUTS in pelvic ischemia: a new concept in voiding dysfunction

Lower urinary tract symptoms (LUTS) are a group of voiding symptoms affecting both genders as they age. Traditionally, LUTS in men were commonly attributed to bladder outlet obstruction (BOO) due to benign prostatic enlargement (BPE). It was later shown that, in approximately one-third to more than one-half of cases, LUTS in men are not associated with BOO. Urodynamic changes in the male bladder and symptom scores in aging men were found to be identical to their age-matched female counterparts. These observations suggested that LUTS in the elderly do not necessarily relate to BOO and may result from local changes in bladder muscle, nerves, and blood vessels. However, aging factors predisposing to bladder dysfunction and LUTS remain unknown. Growing evidence suggests that aging-associated pelvic ischemia may be a primary factor in the development of nonobstructed nonneurogenic overactive bladder and LUTS. First identified in experimental models and later in clinical studies, pelvic ischemia has been shown to compromise the lower urinary tract structure and lead to dysfunction. Structural and functional consequences of bladder and prostate ischemia have been documented in animal models. Clinical studies have shown that bladder and prostate blood flow decreases with aging. The severity of LUTS in elderly patients correlates with the degrees of bladder ischemia. LUTS improvement with α blockers has been associated with increased bladder blood flow. Pelvic ischemia may be an independent factor in nonobstructed nonneurogenic bladder instability and LUTS. Further research into the pathophysiology of LUTS in pelvic ischemia may lead to better management of this problem in the elderly population.

Mirodenafil prevents bladder dysfunction induced by chronic bladder ischemia in rats

Purpose:

To investigate the protective effect of mirodenafil on bladder function in a rat model of chronic bladder ischemia (CBI).

Methods:

Twenty-four Sprague-Dawley rats were randomized to three groups: untreated, sham-operated rats (control group); untreated, CBI model rats (CBI group); and CBI rats treated daily with 4 mg/kg mirodenafil (CBI+mirodenafil group). The CBI and CBI+mirodenafil groups underwent endothelial injury to the iliac arteries and were fed a 2% cholesterol diet after injury. Four weeks after surgery, the CBI+mirodenafil group started daily treatment with mirodenafil for four weeks. Eight weeks after surgery, continuous in vivo cystometry and in vivo organ bath studies of detrusor muscle strips were performed.

Results:

in vivo cystometry revealed that the rats in the CBI group had a significantly higher micturition frequency, lower bladder capacity, and lower compliance than the rats in the control and CBI+mirodenafil groups. The detrusor muscle strip study showed that the magnitude of the carbachol-induced contractile response was significantly lower in the CBI group compared to either the control or CBI+mirodenafil group. Addition of daily mirodenafil after induction of CBI decreased the contractile response, compared to untreated CBI rats. CBI induced submucosal fibrosis and degenerative changes in bladder walls, which was reversed by the addition of mirodenafil.

Conclusions:

Daily treatment with mirodenafil showed protective effects against bladder dysfunction resulting from CBI in rats.

Structural modifications of the prostate in hypoxia, oxidative stress, and chronic ischemia

PURPOSE

Clinical studies have reported a correlation between pelvic ischemia and voiding dysfunction in elderly men. The aim of this study was to identify and compare prostate structural modifications in cultured cells and in a rabbit model after exposure to hypoxia, oxidative stress, and chronic ischemia.

MATERIALS AND METHODS

Cultured human prostate smooth muscle cells (SMCs), epithelial cells (ECs), and stromal cells (SCs) were incubated under normoxia, hypoxia, and oxidative stress conditions by use of a computerized oxycycler system. We developed a rabbit model of chronic prostate ischemia by creating aorto-iliac arterial atherosclerosis. Markers of oxidative stress were examined by using fluorometric analysis and enzyme immunoassay. Prostate structure was examined by using Masson's trichrome staining and transmission electron microscopy (TEM).

RESULTS

Lipid peroxidation was found in SMCs exposed to hypoxia and in all cell types exposed to oxidative stress. We identified protein oxidation in ECs exposed to hypoxia and in all cell types exposed to oxidative stress. Markers indicating oxidative damage were present in chronically ischemic rabbit prostate tissue. These reactions were associated with DNA damage. Prostate ischemia resulted in epithelial atrophy, loss of smooth muscle, and diffuse fibrosis. TEM showed swollen mitochondria with degraded cristae, loss of membrane, loss of Golgi bodies, degenerated nerves, and disrupted cell-to-cell junctions.

CONCLUSIONS

Human prostate cells exhibited differential reactions to hypoxia and oxidative stress with widespread DNA damage. Structural modifications in ischemic prostate tissue were similar to those in cells exposed to oxidative stress. Structural changes due to ischemia and oxidative stress may contribute to prostatic noncompliance in aging men.

Protective effect of tadalafil on the functional and structural changes of the rat ventral prostate caused by chronic pelvic ischemia

BACKGROUND

The etiology of Benign Prostatic Hyperplasia (BPH), a common among aged men, is not fully understood, however, in addition to androgens and aging, chronic ischemia has been proposed to contribute. Using an established rat model, we investigated whether chronic ischemia alters the structural and functional properties of the ventral rat prostate, and whether phosphodiesterase type 5 (PDE5) inhibitor (tadalafil) may have a protective action.

METHODS

Adult male Sprague-Dawley rats were divided into control, arterial endothelial injury (AI), and AI with tadalafil treatment (AI-tadalafil) groups. AI and AI-tadalafil groups underwent endothelial injury of the iliac arteries and received a 2% cholesterol diet following AI. AI-tadalafil rats were treated with tadalafil (2 mg/kg/day) orally for 8 weeks after AI. The control group received a regular diet. After 8 weeks, animals were sacrificed, and pharmacological and morphological studies on prostate tissues were performed.

RESULTS

Iliac arteries from AI rats displayed neo-intimal formation and luminal occlusion, an effect that was not prevented by tadalafil treatment. In the AI group, there was an obvious epithelial atrophy and a statistically significant increase in collagen fibers compared with the controls. Immunohistochemically, there was an up-regulation of smooth muscle α-actin (SMA). Contractile responses of prostate strips to KCl, electrical field stimulation (EFS), and phenylephrine (PE) were significantly higher after AI than in controls. Chronic treatment with tadalafil prevented the increase in contractile responses in ischemic tissue, and decreased the collagen deposition compared with the AI group.

CONCLUSIONS

In this rat model, chronic pelvic ischemia caused distinct functional and morphological changes in the prostate. Prostatic tissue from ischemic animals showed an increased contractile response to electrical and pharmacological stimulation, an increase in SMA, and an increased deposition of collagen. All these changes could be prevented by treatment with the PDE5 inhibitor, tadalafil, suggesting an involvement of cyclic guanosine monophosphate (cGMP).

Pharmacological treatment of chronic pelvic ischemia

Epidemiological studies have shown that lower urinary tract symptoms, including overactive bladder, commonly occur in both men and women, with an age-related increase in both sexes. Vascular endothelial dysfunction and urological symptoms are common in the metabolic syndrome; they also occur during the human ageing process and are independent risk factors for the development of atherosclerosis and hypertension. Pelvic arterial insufficiency may lead to impaired lower urinary tract perfusion and play an important role in the development of bladder dysfunction such as detrusor overactivity and overactive bladder. It seems reasonable, but has not been definitely established clinically, that chronic ischemia-related bladder dysfunction will progress to bladder underactivity. Studies in experimental models in rabbits and rats have shown that pelvic arterial insufficiency may result in significant bladder ischemia with reduced bladder wall oxygen tension, oxidative stress, increased muscarinic receptor activity, ultrastructural damage, and neurodegeneration. Several types of drug may be able to prevent some of these changes. Even if the α1-adrenoceptor blocker, silodosin, the phosphodiesterase type 5 inhibitor, tadalafil, the β3-α1-adrenoceptor agonist, mirabegron, and the free radical scavenger, melatonin, were unable to prevent the development of neointimal hyperplasia and consequent luminal occlusion in animal models, they all exerted a protecting effect on urodynamic parameters, and on the functional and morphological changes of the bladder demonstrable in vitro. The different mechanisms of action of the drugs suggest that many factors are involved in the pathogenesis of chronic ischemia-induced bladder dysfunction and can be targets for intervention. Since several of the agents tested are used clinically and effectively for relieving lower urinary tract symptoms, the results from animal models of chronic bladder ischemia seem to have translational value. Animal models may be of relevance for designing clinical studies to demonstrate if a certain drug may prevent progression of ischemia-related functional and morphological bladder changes.

Effectiveness of diet, sexual habits and lifestyle modifications on treatment of chronic pelvic pain syndrome

BACKGROUND

The potential benefits of a therapeutic regimen for chronic pelvic pain syndrome (CPPS) based on the adherence to some specific rules concerning diet, sexual habits and lifestyle have never been investigated.

METHODS

A review of literature was executed to prepare a vademecum of 13 rules relating to diet, sexual habits and lifestyle that patients had to adhere to in order to treat CPPS. Patients affected by CPPS were enrolled and assigned to two equal groups that were both treated with 100 mg of nimesulide for 1 week. Group two patients were instructed to adhere to the vademecum rules, whereas patients in Group one received instructions to make no changes in their lifestyles. The NIH-Chronic Prostatitis Symptom Index was administered at baseline and after 3 months. The main outcome measure was the change in the mean total NIH-Chronic Prostatitis Symptom Index scores between the two groups from baseline to after treatment. Statistical methods for two-group comparisons were used.

RESULTS

Overall,100 patients were recruited. Thirty-nine out of fifty patients (78%) belonging to Group two adhered to the vademecum rules. In Group one, the total NIH-Chronic Prostatitis Symptom Index score was 21.9 at baseline and 17.6 post-treatment, whereas in Group two these scores were 22.1 and 8.1, respectively (P<0.0001).

CONCLUSIONS

We detected 13 potentially eliminable risk factors for CPPS on the basis of which we prepared a vademecum of 13 rules to treat this disease that were well tolerated and highly effective in significantly reducing all types of symptoms caused by CPPS.

Urinary Tract Symptoms (LUTS) Secondary to Benign Prostatic Hyperplasia (BPH) and LUTS/BPH with Erectile Dysfunction in Asian Men: A Systematic Review Focusing on Tadalafil

This review assesses lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) with or without erectile dysfunction (ED) and related therapies focusing on tadalafil. A literature search was obtained and reviewed for the epidemiology, treatment therapies, pathophysiology, and efficacy and safety of phosphodiesterase type 5 inhibitor (PDE5i) tadalafil in patients with LUTS/BPH. Approximately 42% of men aged 51 to 60 years have BPH. Approximately 90% of men aged 45 to 80 years have LUTS. Occurrence of LUTS increases with age for almost all racial/ethnic groups (range, 32% to 56%) with prevalence of LUTS highest among Hispanic men, then Blacks, Caucasians, and Asians. There is an independent relationship with LUTS/BPH and ED, with approximately 70% of men with LUTS/BPH having ED with severity of one disease often correlating with the other. The European Urological Association guidelines include the use of the PDE5i tadalafil. Tadalafil is the only therapy recommended for treatment of co-existing BPH and ED, while other therapies have unwanted ED side effects. The mode of action of tadalafil may involve different areas of the lower urinary tract such as smooth muscle cell relaxation in the bladder neck, prostate, and urethra, but there may also be resulting modulation of the afferent nerve activity. Tadalafil (5 mg) in Asian men with LUTS/BPH, similar to global studies, is efficacious and safe. Tadalafil (5 mg) improves co-existing LUTS/BPH and ED, independently. Men with LUTS/BPH likely also have ED. Asian men with LUTS/BPH have similar incidence rates, co-existing ED, comorbid diseases, and risks as non-Asian men. Tadalafil can improve co-existing LUTS/BPH and ED.

Prophylactic effect of tadalafil on bladder function in a rat model of chronic bladder ischemia

PURPOSE

We investigated the effect of tadalafil on chronic ischemia related bladder dysfunction.

MATERIALS AND METHODS

Adult male Sprague-Dawley® rats were divided into control, arterial endothelial injury and arterial endothelial injury with tadalafil treatment groups. The arterial injury and arterial injury-tadalafil groups underwent endothelial injury of the iliac arteries and received a 2% cholesterol diet after injury. Arterial injury-tadalafil rats received tadalafil (2 mg/kg per day) orally for 8 weeks after injury. The control group received a regular diet. At 8 weeks urodynamic investigation was performed. Bladder tissue was harvested for pharmacological studies, and histological examination of the iliac arteries and bladders was performed.

RESULTS

Iliac arteries from arterial injury and arterial injury-tadalafil rats showed neointimal formation and luminal occlusion. In the arterial injury group the micturition interval was significantly shorter (mean ± SEM 5.4 ± 0.5 vs 11.1 ± 1.1 minutes), and bladder capacity and voided volume were less than in controls. Contractile responses of bladder strips to KCl, electrical field stimulation and carbachol were significantly less after arterial injury than in controls. The arterial injury group showed a significantly increased percent of collagen compared with controls (mean 37.4% ± 1.8% vs 21.5% ± 1.8%). In the arterial injury-tadalafil group intimal formation and luminal occlusion were not prevented. However, there were significant improvements in all functional and morphological parameters compared with the arterial injury group.

CONCLUSIONS

Arterial occlusive disease may lead to chronic bladder ischemia and bladder hyperactivity. Chronic treatment with tadalafil protects bladder function and morphology, resulting in decreased bladder hyperactivity. If valid for humans, the data support phosphodiesterase 5 inhibition as treatment for chronic ischemia related bladder dysfunction.

The mechanism of action of phosphodiesterase type 5 inhibitors in the treatment of lower urinary tract symptoms related to benign prostatic hyperplasia

CONTEXT

Clinical trials of phosphodiesterase type 5 inhibitors (PDE5-Is) have consistently demonstrated a significant reduction in lower urinary tract symptoms (LUTS) and small urinary flow rate changes in men with benign prostatic hyperplasia (BPH).

OBJECTIVE

This review presents the proposed mechanisms of action of PDE5-Is in the treatment of BPH-LUTS focusing on the localization of PDE5 isoenzymes in the pelvic structures; smooth muscle relaxation in the bladder, prostate, and supporting vasculature; increased blood perfusion of the bladder and prostate; and modulation of sensory impulses from these organs.

EVIDENCE ACQUISITION

Literature describing in vitro, preclinical, or clinical studies of pathologic processes contributing to LUTS or effects of PDE5 inhibition on the lower urinary tract (LUT) was selected for review.

EVIDENCE SYNTHESIS

We objectively assessed and summarized the published data focusing on articles published within the past 10 yr. Articles before the time cut-off were included if historically relevant.

CONCLUSIONS

The PDE5 isoenzymes are highly expressed in the LUT including the bladder, prostate, and their supporting vasculature. In vitro assays have demonstrated PDE5-Is by regulating cyclic guanosine monophosphate (cGMP) degradation and enhancing the nitric oxide/cGMP signaling pathway to relax human smooth muscle strips from the prostate, bladder, and LUT arteries. In animals characterized by ischemia/hypoxia of the genitourinary tract, treatment with PDE5-Is increases bladder and prostate tissue oxygenation. PDE5-Is have been shown to reduce nonvoiding contractions and bladder afferent nerve firing in decerebrate spinal cord-injured rats, and to reduce mechanosensitive afferent activities of both Aδ- and C-fibers in an irritated or overextended bladder model.

Benign prostatic hyperplasia: from bench to clinic

Benign prostatic hyperplasia (BPH) is a prevalent disease, especially in old men, and often results in lower urinary tract symptoms (LUTS). This chronic disease has important care implications and financial risks to the health care system. LUTS are caused not only by mechanical prostatic obstruction but also by the dynamic component of obstruction. The exact etiology of BPH and its consequences, benign prostatic enlargement and benign prostatic obstruction, are not identified. Various theories concerning the causes of benign prostate enlargement and LUTS, such as metabolic syndrome, inflammation, growth factors, androgen receptor, epithelial-stromal interaction, and lifestyle, are discussed. Incomplete overlap of prostatic enlargement with symptoms and obstruction encourages focus on symptoms rather than prostate enlargement and the shifting from surgery to medicine as the treatment of BPH. Several alpha antagonists, including alfuzosin, doxazosin, tamsulosin, and terazosin, have shown excellent efficacy without severe adverse effects. In addition, new alpha antagonists, silodosin and naftopidil, and phosphodiesterase 5 inhibitors are emerging as BPH treatments. In surgical treatment, laser surgery such as photoselective vaporization of the prostate and holmium laser prostatectomy have been introduced to reduce complications and are used as alternatives to transurethral resection of the prostate (TURP) and open prostatectomy. The status of TURP as the gold standard treatment of BPH is still evolving. We review several preclinical and clinical studies about the etiology of BPH and treatment options.

Correlations among cardiovascular risk factors, prostate blood flow, and prostate volume in patients with clinical benign prostatic hyperplasia

OBJECTIVE

To investigate the relationships among the cardiovascular risk factors, prostate blood flow, and prostate volume in patients with clinical benign prostatic hyperplasia (BPH).

METHODS

A total of 130 patients with the clinical diagnosis of BPH were recruited. The presence of 5 cardiovascular risk factors, including obesity, diabetes, hypertension, hyperlipidemia, and a history of cardiovascular events, was recorded. The urologic evaluation included digital rectal examination, serum prostate-specific antigen, International Prostate Symptom Score, and transrectal ultrasonography. Doppler spectrum analysis was performed with the patient in the right lateral decubitus position to measure the blood flow in the prostate capsular arteries, periurethral arteries, and neurovascular bundles. The correlations were analyzed between the resistive indexes of the prostatic branches and the cardiovascular risk factors, as well as the transrectal ultrasound findings.

RESULTS

The resistive indexes of the periurethral arteries and right neurovascular bundles showed positive correlations with the number of cardiovascular risk factors in the patients (r=.228, P=.01 and r=.225, P=.011, respectively). The periurethral artery resistive index also correlated positively with both prostate and transitional zone volumes, with the capsular artery correlating positively only with the latter. No significant correlations were noted between the resistive indexes and the International Prostate Symptom Score.

CONCLUSION

Prostate vascular resistance in patients with BPH has positive correlations with cardiovascular risk factors and prostate size. These findings suggest that prostate hypoxia might play a role in the pathogenesis of BPH.

Current benign prostatic hyperplasia treatment: impact on sexual function and management of related sexual adverse events

Benign prostatic hyperplasia (BPH) is a common disease in older men that can lead to lower urinary tract symptoms (LUTS). Male sexual dysfunction is also an age-related condition. Epidemiological studies have confirmed an association between BPH/LUTS and sexual dysfunction in ageing men that is independent of the effects of age, other co-morbidities and lifestyle factors. Proposed pathophysiological mechanisms for BPH/LUTS-associated sexual dysfunction include the nitric oxide/cyclic guanosine monophosphate (NO/cGMP) pathway, rho-kinase and endothelin-1 activity, autonomic nervous system overactivity and the metabolic syndrome, and pelvic organ atherosclerosis. Both BPH/LUTS and sexual dysfunction can have a substantial negative impact on a man's quality of life. However, urologists and primary care physicians appear to under-recognise sexual dysfunction in men with BPH/LUTS. Current guidelines recommend alpha-blockers and 5-alpha reductase inhibitors, either alone or in combination, among appropriate medical treatment options for BPH/LUTS. Randomised, controlled trials demonstrate that these therapies can be associated with sexual adverse effects (AEs) such as loss of libido, erectile dysfunction and ejaculatory disorders. Sexual dysfunction should be fully evaluated in men requiring treatment for BPH/LUTS using validated questionnaires. Management of sexual dysfunction in men treated for BPH/LUTS should involve assessment of co-morbidities and concomitant medications, consideration of lifestyle interventions such as weight loss and increased physical activity to improve risk factors and, if necessary, introduction of pharmacotherapies. In addition, physicians should provide patients with proper counselling on the possible sexual AEs of medical therapies for BPH/LUTS and their impact on sexual satisfaction, while being aware of the possibility that counselling in itself is likely to influence reported rates of sexual dysfunction.

Metabolic syndrome and benign prostatic hyperplasia: evidence of a potential relationship, hypothesized etiology, and prevention

Benign prostatic hyperplasia (BPH) is highly prevalent in older men and causes substantial adverse effects on health. The pathogenesis of this disease is not totally clear. Recent reports have suggested a possible relationship between metabolic syndrome (MetS) and BPH. Single components of MetS (obesity, dyslipidemia, hypertension, and insulin resistance) as well as the syndrome itself may predispose patients to a higher risk of BPH and lower urinary tract symptoms (LUTS). This may stem from changes in insulin resistance, increased autonomic activity, impaired nitrergic innervation, increased Rho kinase activity, pro-inflammatory status, and changes in sex hormones that occur in association with MetS. However, the exact underlying mechanisms that regulate the potential relationship between MetS and BPH/LUTS still need to be clarified. Increased physical activity and dietary strategies may help in decreasing the incidence of MetS and its impact on BPH/LUTS. However, differences in the definitions used to address the examined predictors and endpoints preclude the possibility of arriving at definitive conclusions.

Tadalafil for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia: pathophysiology and mechanism(s) of action

BACKGROUND

The PDE5 inhibitor tadalafil is investigation for the treatment of lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH). Several clinical studies of tadalafil and other PDE5 inhibitors have reported significant symptom reduction but limited urinary flow rate improvement. This manuscript reviews the published literature describing the pathophysiology of male LUTS, with an emphasis on mechanisms that may be modulated or improved by phosphodiesterase type 5 (PDE5) inhibition.

METHODS

Literature (through March 2010) was obtained via Medline searches and from the individual reviewers files. Articles were selected for review based on describing in vitro, preclinical, or clinical studies of pathological processes contributing to LUTS, or possible effects of PDE5 inhibition in the lower urinary tract.

RESULTS

Major mechanisms contributing to LUTS include: reduced nitric oxide/cyclic guanosine monophosphate signaling; increased RhoA kinase pathway activity; autonomic overactivity; increased bladder afferent activity; and pelvic ischemia. Tadalafil and other PDE5 inhibitors have demonstrated beneficial effects on smooth muscle relaxation, smooth muscle and endothelial cell proliferation, nerve activity, and tissue perfusion that may impact LUTS in men.

CONCLUSIONS

The pathophysiology of male LUTS is complex and not completely understood. LUTS may occur independently of BPH or secondary to BPH but in both cases involve obstructive or irritative mechanisms with substantial pathophysiological overlap. While the precise mechanism remains unclear, inhibition of PDE5 seems to have an effect on several pathways that may impact LUTS.

[Treatment of the lower urinary tract symptoms secondary to benign prostatic hyperplasia by phosphodiesterase type 5 inhibitors. Review article]

CONTEXT

In aging males, there is an increased prevalence of lower urinary tract symptoms (LUTS) related to benign prostatic hyperplasia (BPH) and erectile dysfunction (ED) whose affect significantly their quality of life. LUTS would represent for ED an independent risk factor. Some treatment of LUTS have undesirable effects on the erectile function. The phosphodiesterase type 5 inhibitors (IPDE 5) revolutionized the treatment of ED. Several recent clinical studies evaluated the effect daily treatment by IPDE 5 on the LUTS secondary to BPH among patients with or without ED.

MATERIALS AND METHODS

we searched Medline for the peer-reviewed articles in English published, pertaining to findings of potential interest supporting a role of IPDE5 in LUTS due to BHP. The keywords used were: benign prostatic hyperplasia; cyclic nucleotide phosphodiesterase type 5; lower urinary tract symptoms; erectile dysfunction.

RESULTS

Generally, daily treatment with IPDE 5 improves the LUTS secondary to BPH as well as in both the storage and voiding domains of the international prostate symptom score (IPPS) and in quality of life questionnaire. It was not observed adverse events.

CONCLUSION

The first results of the use of IPDE 5 in the LUTS treatment secondary to the HBP seem promising. However, a direct comparison of efficacy of IPDE 5 and alpha-blockers or 5-alpha-reductase inhibitors is not yet available. The mechanism(s) of action(s) of these compounds in this indication remain difficult to affirm even if new hypotheses can be formulated.

Phosphodiesterase 5 inhibitors for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a systematic review

OBJECTIVE

• To review the evidence in support of the effectiveness of phosphodiesterase 5 inhibitors in lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH).

METHODS

• Relevant studies were identified by performing a literature search using MEDLINE® and The Cochrane Library®. The criteria used during the search included randomized, placebo-controlled trials of treatment for LUTS secondary to BPH using the International Prostate Symptom Score as an outcome measure.

RESULTS

• Four trials that included a total of 1928 patients met the inclusion criteria. All four studies showed a statistically significant difference in the International Prostate Symptom Score, quality of life and erectile function in favour of phosphodiesterase 5 inhibitors. • No study showed a statistically significant improvement of the maximum urinary flow. • Meta-analysis of the results was not possible because of heterogeneity across the studies.

CONCLUSIONS

• Phosphodiesterase 5 inhibitors used in the clinical setting can significantly improve LUTS secondary to BPH, erectile function and quality of life. Maximum urinary flow improvement is not statistically significant. • Future research should focus on pathophysiological principles and cost analysis.

Effects of tadalafil on lower urinary tract symptoms secondary to benign prostatic hyperplasia in men with or without erectile dysfunction

OBJECTIVES

To compare the safety and efficacy of the daily erectogenic therapy, tadalafil, on lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH-LUTS) in men with or without comorbid erectile dysfunction (ED).

METHODS

Following a 4-week placebo run-in period, men with moderate-to-severe BPH-LUTS were randomized to placebo or tadalafil 2.5, 5, 10, or 20 mg once daily for 12 weeks. International Prostate Symptom Scores (IPSS), IPSS quality of life, and BPH Impact Index were measured every 4 weeks. Safety was mainly assessed via spontaneous reports of adverse events. Data from men with (n=716) or without (n=340) ED at baseline were compared in posthoc analyses.

RESULTS

Men with ED were older and had more frequent hypertension, hyperlipidemia, coronary artery disease, and diabetes at baseline compared with men without ED. After 12 weeks, changes in IPSS in men with ED (least squares mean change from baseline, placebo: -2.4; tadalafil 2.5, 5, 10, 20 mg: -4.3, -4.8, -5.3, -5.6) and without ED (-2.4, -3.2, -5.3, -5.1, -4.5) were not significantly different (subgroup/interaction P values: .352/.644). Similar effects were observed for IPSS quality of life (with ED: -0.6, -0.9, -0.9, -1.0, -1.1; without ED: -0.6, -0.7, -0.9, -0.8, -0.8; 0.090/0.773) and BPH Impact Index (with ED: -0.7, -0.9, -1.3, -1.3, -1.4; without ED: -1.0, -0.7, -1.3, -1.3, -1.2; 0.753/0.852). Tadalafil was generally well tolerated, and men with or without ED had similar tolerability profiles.

CONCLUSIONS

Changes in BPH-LUTS after 12 weeks of treatment with placebo or various doses of once daily tadalafil were similar in men with or without comorbid ED.

Urodynamic effects of once daily tadalafil in men with lower urinary tract symptoms secondary to clinical benign prostatic hyperplasia: a randomized, placebo controlled 12-week clinical trial

PURPOSE

We explored the impact of once daily tadalafil on urodynamic measures in men with lower urinary tract symptoms secondary to clinical benign prostatic hyperplasia via invasive and noninvasive urodynamic studies.

MATERIALS AND METHODS

We conducted a multicenter, randomized, double blind, placebo controlled clinical trial comparing once daily tadalafil 20 mg vs placebo during 12 weeks in men with lower urinary tract symptoms secondary to clinical benign prostatic hyperplasia with or without bladder outlet obstruction. Invasive and noninvasive urodynamics, International Prostate Symptom Score and general safety were assessed. The primary study end point was change in detrusor pressure at maximum urinary flow rate.

RESULTS

Urodynamic measures remained largely unchanged during the study with no statistically significant or clinically adverse difference between tadalafil and placebo in change in detrusor pressure at maximum urinary flow rate (mean difference between treatments -2.2 cm H(2)O, p = 0.33) or any other urodynamic parameter assessed including maximum urinary flow rate, maximum detrusor pressure, bladder outlet obstruction index or bladder capacity (all measures p > or = 0.13). Treatment with tadalafil resulted in significant improvements in International Prostate Symptom Score (mean difference between treatments -4.2, p < 0.001). Tadalafil was generally well tolerated with the majority of adverse events being mild to moderate in severity and few patients discontinuing due to adverse events (tadalafil 2.0%, placebo 1.0%).

CONCLUSIONS

Treatment with tadalafil once daily for lower urinary tract symptoms secondary to clinical benign prostatic hyperplasia showed no negative impact on bladder function as measured by detrusor pressure at maximum urinary flow rate or on any other urodynamic parameter assessed. Nonetheless men receiving tadalafil reported significant improvements in International Prostate Symptom Score with an adverse events profile similar to other recent studies of tadalafil for lower urinary tract symptoms secondary to clinical benign prostatic hyperplasia.

Changes in peak urinary flow and voiding efficiency in men with signs and symptoms of benign prostatic hyperplasia during once daily tadalafil treatment

OBJECTIVE

To determine, by post hoc analysis, the effects of tadalafil (a long-acting phosphodiesterase 5 inhibitor) on peak urinary flow (Q(max)), bladder capacity, voiding efficiency and the obstructive symptoms of benign prostatic hyperplasia (BPH) in men with lower urinary tract symptoms secondary to BPH (BPH-LUTS), compared with placebo.

PATIENTS AND METHODS

After a 4-week placebo run-in period, 1058 men with BPH-LUTS were randomly allocated to receive once daily treatment with placebo or tadalafil (2.5, 5, 10, or 20 mg) for 12 weeks. Uroflowmetry, postvoid residual volume (PVR), and BPH symptom score measurements were assessed throughout the trial.

RESULTS

Increases in Q(max) were numerically greater for tadalafil (2.5, 5, 10, and 20 mg with percentage changes of 15%, 16%, 17%, 22%, respectively) vs placebo (12%), but did not reach statistical significance. Age, baseline Q(max), erectile dysfunction history, sexual activity, and previous alpha-blocker therapy significantly influenced the Q(max) response. Tadalafil was not associated with significant changes in PVR. Tadalafil had its greatest effects on bladder capacity and voiding efficiency in men with a Q(max) of <10 mL/s at baseline, but these changes were not significantly different from placebo responses. Tadalafil treatment significantly improved the IPSS obstructive subscores (tadalafil 2.5, 5, 10, 20 mg with percentage changes of 24%, 31%, 33%, 33%, respectively) vs placebo (13%).

CONCLUSIONS

Once daily tadalafil did not significantly change Q(max) or voiding efficiency compared with placebo in men with BPH-LUTS, although there were dose-dependent improvements. No subgroups were identified where tadalafil or placebo treatment had a deleterious effect on Q(max). Despite these minimal changes in uroflowmetric measures, tadalafil was associated with clinically meaningful and statistically significant improvements in the obstructive symptoms of BPH.

PDE5 inhibitors for LUTS

To review the current literature regarding the relationship between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED), and the role of phosphodiesterase-5 (PDE5) inhibitors for the treatment of LUTS. Review of recently published (1990-2009) data regarding epidemiologic and pathophysiologic mechanisms are involved in LUTS-ED, focusing on PDE5 inhibitors particularly evidenced from level 1 clinical trials. Search terms included phosphodiesterase inhibitors, nitric oxide, autonomic hyperactivity, Rho-kinase, atherosclerosis, LUTS, benign prostatic hypertrophy, and ED. Results of several epidemiologic studies show a possible causal relationship between LUTS and ED. Four possible mechanisms have been proposed to explain this association. Multiple large clinical trials have shown a benefit in LUTS after PDE5-inhibitors treatment. PDE5 inhibitors show promise as a future treatment for LUTS, either in conjunction with existing therapies or as a primary treatment.

Is there a rationale for the chronic use of phosphodiesterase-5 inhibitors for lower urinary tract symptoms secondary to benign prostatic hyperplasia?

OBJECTIVES

To critically review the physiological roles of phosphodiesterase-5 (PDE5), to explain and support the putative impact and clinical significance of PDE5 inhibitors (PDE5-Is) in the treatment of lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) and erectile dysfunction (ED), both highly prevalent in men aged > or =50 years, as PDE5-Is are very effective as a first-line therapy for ED, and attractive for further physiological functional investigations.

METHODS

We searched Medline for peer-reviewed articles in English, from 1991 to 2008, to provide a critical contemporary review of PDE5 pertaining to the potential interest of findings supporting a role for PDE5-Is in LUTS due to BPH. The selection of papers was based on the relevance of subject matter. A critical analysis of available fundamental and clinical data is reported.

RESULTS

Several studies assessed the role of the nitric oxide/cGMP signalling pathway in the regulation of the prostate tone, with the support of clinical observations. PDE5-Is can also represent a potential mode of action allowing the targeting of transcriptional activity implicated in the regulation of the progression of the inflammatory process involved in BPH. PDE5-Is can inhibit human stromal cell proliferation of the prostate mediated by cGMP accumulation. New targeting hypotheses of pathophysiological processes are also reported.

CONCLUSIONS

There is evidence that LUTS and ED are strongly linked. This analysis of the regulatory basis of PDE5 biology could indicate several directions of investigation. However, it is necessary to devise well-designed large prospective studies that would produce significant data before this approach becomes a standard of care.

Erectile dysfunction and lower urinary tract

During the last decades it turned out that the NO/cGMP signaling cascade is one of the most prominent regulators of a variety of physiological and pathophysiological processes in a broad range of mammalian tissues. Thus cGMP is a key second messenger and targeting this pathway by increasing intracellular cGMP levels is a very successful approach in pharmacology as shown for nitrates, PDE5 inhibitors and more recently for stimulators of the guanylate cyclase. Besides the beneficial effects of cGMP elevation in cardiac, vascular, pulmonary, renal or liver disorders the launch of PDE5 inhibitors for the treatment of erectile dysfunction 10 years ago, has directed a lot of attention to the NO/cGMP signaling in the lower urinary tract. Triggered by the use of PDE5 inhibitors in ED it turned out that cGMP is a common regulatory mechanism for lower urinary tract function also beyond ED. In recent years intense research and development efforts were undertaken to elucidate the role of the NO/cGMP and to fully exploit the therapeutic implications of cGMP elevation in urological disorders in ED and beyond. Therefore we have summarized the effects of cGMP elevation for treatment of erectile dysfunction in males and in females. We have also reviewed the recent pre-clinical and clinical lines of evidence for treatment options of benign prostatic hyperplasia and lower urinary tract symptoms in male patients and overactive bladder and urinary incontinence in female patients. In addition we also touch more speculative concepts using cGMP elevating drugs for the treatment of premature ejaculation, peyornies disease and stone disease.