Immunogenicity and safety following one dose of AS01E-adjuvanted respiratory syncytial virus prefusion F protein vaccine in older adults: a phase 3 trial.

BACKGROUND: The recently approved AS01E-adjuvanted respiratory syncytial virus (RSV) prefusion F protein-based vaccine (RSVPreF3 OA) demonstrated high efficacy against RSV-related disease in ≥60-year-olds. METHODS: This ongoing phase 3 study in ≥60-year-olds evaluates the immune persistence until three years post-RSVPreF3 OA vaccination. Here, we describe interim results on humoral and cell-mediated immunogenicity, reactogenicity, and safety until one year post-dose 1. RESULTS: In total, 1653 participants were vaccinated. One month post-dose 1, neutralization titers increased 10.5-fold (RSV-A) and 7.8-fold (RSV-B) versus pre-dose 1. Titers then declined to levels 4.4-fold (RSV-A) and 3.5-fold (RSV-B) above pre-dose 1 at month 6, and remained 3.1-fold (RSV-A) and 2.3-fold (RSV-B) above pre-dose 1 levels after one year. RSVPreF3-binding immunoglobulin G levels and CD4+ T-cell frequencies showed similar kinetics. Solicited administration-site and systemic adverse events (mostly mild to moderate and transient) were reported by 62.2% and 49.5% of participants. Serious adverse events were reported by 3.9% of participants within 6 months post-dose 1; one case was considered vaccine-related. CONCLUSIONS: One RSVPreF3 OA dose elicited cell-mediated and RSV-A and RSV-B-specific humoral immune responses that declined over time but remained above pre-dose 1 levels for at least one year. The vaccine was well tolerated with an acceptable safety profile.Clinicaltrials.gov NCT04732871.

Respiratory syncytial virus (RSV) is a major cause of illness and hospitalization in older adults. An RSV vaccine for older adults developed by GSK was recently approved. The vaccine was well tolerated and provided protection against RSV disease in adults aged 60 years and older during at least one RSV season. In this ongoing study, we are evaluating the magnitude and durability of the immune response, as well as vaccine safety, until three years after vaccination of adults aged 60 years and older from five countries. Here, we report the results of an interim analysis until one year after vaccination with one dose. In total, 1653 participants were vaccinated. We found that the vaccine induced a strong immune response that was evident one month after vaccination, after which it declined, but persisted for at least one year. Study participants most often reported pain at the injection site, muscle pain, tiredness, and headache as adverse reactions, which were mostly mild to moderate and of short duration. One serious adverse reaction was considered related to the vaccine. The long-term immune response that was observed in this study is consistent with the vaccine providing protection during at least one RSV season.

Safety, tolerability, and immunogenicity of a 21-valent pneumococcal conjugate vaccine, V116, in Japanese healthy adults: A Phase I study.

V116 is an investigational 21-valent pneumococcal conjugate vaccine (PCV) to address the burden of residual adult pneumococcal disease after the introduction of pediatric PCVs into national immunization programs (NIPs) and includes serotypes highly prevalent in adult invasive pneumococcal disease (IPD). This Phase I study assessed the safety, tolerability, and immunogenicity of V116 in Japanese adults. Participants ≥20 years of age were randomized to receive a single dose of V116 or 23-valent pneumococcal polysaccharide vaccine (PPSV23) at day 1. Outcomes were solicited injection-site and systemic adverse events (AEs) from day 1 to day 5, vaccine-related serious AEs from day 1 through day 30, and serotype-specific opsonophagocytic antibody (OPA) titers and immunoglobulin G (IgG) concentrations at day 30. Overall, 102 participants were randomized 1:1 to each group. Comparable proportions vaccinated with V116 and PPSV23 experienced ≥1 solicited injection-site AE and ≥1 solicited systemic AE. The most common injection-site AEs were injection-site pain (V116: 54.9%; PPSV23: 66.7%) and swelling (V116 and PPSV23: 13.7%), and the most common systemic AEs were myalgia (V116: 17.6%; PPSV23: 19.6%) and fatigue (V116: 13.7%; PPSV23: 9.8%). Solicited AEs were mostly mild and of ≤3 days duration. No vaccine-related serious AEs or deaths were reported. The OPA and IgG findings showed that the immunogenicity of V116 and PPSV23 were comparable for the 12 common serotypes and V116 was more immunogenic for the nine unique serotypes compared with PPSV23. V116 was well tolerated, with a safety profile similar to PPSV23, and induced functional antibodies against all 21 serotypes.

Variability of post-void residual urine volume and bladder voiding efficiency in patients with underactive bladder.

OBJECTIVES: Post-void residual urine volume (PVR) and bladder voiding efficiency (BVE) are widely used as clinical parameters to evaluate patients with voiding dysfunction. The present study was conducted to assess the variability of PVR and BVE determinations in patients with underactive bladder (UAB). In addition, we focused on the bladder volume prior to voiding (BVvoid ) that may influence PVR and BVE, and investigated a correlation between PVR and BVvoid , and between BVE and BVvoid . METHODS: Ten patients with a symptom complex of UAB, who had PVR of 50 mL or greater, were admitted to hospital during a 24-hour period for the measurement of voided volume (VV) and PVR. PVR was measured by transabdominal ultrasonography. BVE was expressed by a fraction (%) of bladder volume evacuated ([VV/BVvoid ] × 100). RESULTS: Ten patients, five men (mean age of 65.0 years) and five women (mean age of 70.2 years), participated in this study. Regardless of gender, there was a large variation in repeated measurements of PVR in an individual patient. PVR increased with an increase in BVvoid , and there was a significant linear relationship between PVR and BVvoid . BVE was approximately constant after every voiding in each patient, and there was no significant linear relationship between BVE and BVvoid . CONCLUSIONS: Measurement of PVR was unreliable because of wide variation in the same individual. The variation of BVE was much smaller than PVR. BVE would be a reliable parameter with good reproducibility for the assessment of emptying function.

Clinical diagnostic criteria for detrusor underactivity: A report from the Japanese Continence Society working group on underactive bladder.

Detrusor underactivity (DU) is a common bladder dysfunction that causes lower urinary tract symptoms (LUTS) in both men and women. Currently DU can only be diagnosed by an invasive urodynamic test. Underactive bladder (UAB) is the symptom-based correlate of DU, as is the case with overactive bladder (OAB) and detrusor overactivity (DO). The International Continence Society (ICS) consensus group has recently proposed a working definition of UAB as a symptom syndrome suggestive of DU. However, a symptom complex of UAB is shared by LUTS attributable to bladder outlet obstruction (BOO). Thus, UAB is not specific for DU, leading to difficulties in determining a therapeutic target (DU or BOO) in the initial management of UAB. Under these circumstances, a consensus group was formed under the auspices of the Japanese Continence Society (JCS) and diagnostic criteria were produced to potentially identify patients likely to have DU, without a pressure/flow study-based diagnosis. Certain symptoms and several noninvasive test parameters have been reported as clinical predictors of DU, and were suggested to discriminate DU from BOO. Of these predictive factors, the more commonly used parameters were used to develop clinical diagnostic criteria for DU. This article presents the clinical diagnostic criteria for DU proposed by the JCS consensus group and aims to summarize the background discussion by the group.

TAS-303 effects on urethral sphincter function in women with stress urinary incontinence: phase I study.

INTRODUCTION AND HYPOTHESIS: TAS-303, which selectively inhibits noradrenaline reuptake, was developed for treating stress urinary incontinence (SUI). The proximal urethra mainly comprises smooth muscle fibers in which α1 adrenergic receptors are abundant. This study was conducted to evaluate the effect of TAS-303 on urethral function and its safety profile in female patients with SUI. METHODS: In total, 16 women (age, 20-64 years) with SUI and > 5.0 g of leakage in the 1-h pad test at screening were randomized and administered the assigned treatment in a double-blind manner. The primary end point was change in the maximal urethral closure pressure (MUCP) at 6 h post-dose. The secondary end point was change in the urethral closure pressure of the entire urethra and each urethral region (proximal, middle, and distal) at 6 h post-dose. The results were analyzed using a t-test. RESULTS: The mean change ± standard deviation in MUCP at 6 h post-dose was 3.473 ± 12.154 cmH2O for TAS-303 and 2.615 ± 9.794 cmH2O for placebo (between-group difference: 0.858 cmH2O, P = 0.8047). The mean changes ± standard deviation in urethral closure pressure of the proximal urethra at 6 h after the administration of TAS-303 18 mg and placebo were 3.863 ± 10.941 and 1.634 ± 12.093, respectively (between-group difference: 2.229 cmH2O, P = 0.5976). CONCLUSIONS: No significant difference in MUCP and urethral closure pressure was found between TAS-303 and placebo. However, the change in the proximal urethral closure pressure with TAS-303 was larger than that with placebo. This suggests that TAS-303 has pharmacological effects on urethral sphincteric function.

Clinical characteristics and useful signs to differentiate detrusor underactivity from bladder outlet obstruction in men with non-neurogenic lower urinary tract symptoms.

OBJECTIVE: To investigate the clinical characteristics and useful signs to differentiate detrusor underactivity from bladder outlet obstruction in men with non-neurogenic lower urinary tract symptoms. METHODS: A total of 638 treatment-naive men with non-neurogenic lower urinary tract symptoms who underwent subjective and objective evaluations were reviewed retrospectively. We divided the patients into detrusor underactivity and bladder outlet obstruction groups based on urodynamic findings, and compared parameters obtained from questionnaires and non-invasive tests. Detrusor underactivity was defined as bladder contractility index ≤100 and bladder outlet obstruction index ≤40, whereas bladder outlet obstruction was defined as bladder contractility index >100 and bladder outlet obstruction index >40. RESULTS: Of 638 patients, 145 (22.7%) had detrusor underactivity and 273 (42.8%) had bladder outlet obstruction. Total international prostate symptom score and international prostate symptom score-voiding subscore were significantly higher in the detrusor underactivity group. There were significant differences in prostate volume, intravesical prostatic protrusion, and all uroflowmetry parameters between the two groups. In multivariate logistic regression analysis, lower intravesical prostatic protrusion (cut-off value 8.2 mm), lower bladder voiding efficiency (cut-off value 70%), and the presence of sawtooth and interrupted waveform on uroflowmetry were significant predictive factors for detrusor underactivity. In particular, the incidence of sawtooth and interrupted waveform was significantly higher in the detrusor underactivity group (80%) than in the bladder outlet obstruction group (12.8%), which showed both high sensitivity (80%) and specificity (87.2%) in differentiating detrusor underactivity from bladder outlet obstruction. CONCLUSIONS: Sawtooth and interrupted waveform on uroflowmetry can be a useful predictive factor for detrusor underactivity. In addition, lower intravesical prostatic protrusion and bladder voiding efficiency can be of supplementary use.

Phase I study of KRP-116D, a 50% w/w dimethyl sulfoxide aqueous solution, on the systemic absorption from bladder by intravesical instillation in healthy Japanese subjects.

OBJECTIVE: This was a single-institution, single-dose, single-arm phase 1 study in healthy adult males to evaluate the safety and absorption of dimethyl sulfoxide (DMSO) from the bladder into the body when KRP-116D (a 50% w/w DMSO solution) was intravesically administered and allowed to remain in the bladder for 15 minutes. METHODS: Six healthy adult males were enrolled in this study. KRP-116D (50 mL) was instilled directly into the bladder via a catheter where it was allowed to remain for 15 minutes under lidocaine anesthesia in accordance with the usage of RIMSO-50 (50% w/w DMSO solution) approved in the USA. The residual DMSO solution in the bladder was collected 15 minutes after instillation. The concentrations of DMSO in the plasma and the recovered solution were analyzed by a validated high-performance liquid chromatography (HPLC) method. The concentration in the residual DMSO solution was multiplied by the solution volume and divided by the dosage to calculate the recovery rate of DMSO. RESULTS: Plasma DMSO was detected in one of six subjects, and in the remaining five subjects DMSO was not detected (<19.6 µg/mL). The recovery rate of DMSO from the bladder was 60.7% to 93.7%. The only drug-related adverse event was breath odor (garlic-like breath) observed in four of six subjects (66.7%). CONCLUSION: Absorption of DMSO from the bladder was low (16.3%), and the systemic exposure was limited. Most of the DMSO was recovered from the bladder. KRP-116D 50 mL was well tolerated and safe.

Recapitulation of Clinical Individual Susceptibility to Drug-Induced QT Prolongation in Healthy Subjects Using iPSC-Derived Cardiomyocytes.

To predict drug-induced serious adverse events (SAE) in clinical trials, a model using a panel of cells derived from human induced pluripotent stem cells (hiPSCs) of individuals with different susceptibilities could facilitate major advancements in translational research in terms of safety and pharmaco-economics. However, it is unclear whether hiPSC-derived cells can recapitulate interindividual differences in drug-induced SAE susceptibility in populations not having genetic disorders such as healthy subjects. Here, we evaluated individual differences in SAE susceptibility based on an in vitro model using hiPSC-derived cardiomyocytes (hiPSC-CMs) as a pilot study. hiPSCs were generated from blood samples of ten healthy volunteers with different susceptibilities to moxifloxacin (Mox)-induced QT prolongation. Different Mox-induced field potential duration (FPD) prolongation values were observed in the hiPSC-CMs from each individual. Interestingly, the QT interval was significantly positively correlated with FPD at clinically relevant concentrations (r > 0.66) in multiple analyses including concentration-QT analysis. Genomic analysis showed no interindividual significant differences in known target-binding sites for Mox and other drugs such as the hERG channel subunit, and baseline QT ranges were normal. The results suggest that hiPSC-CMs from healthy subjects recapitulate susceptibility to Mox-induced QT prolongation and provide proof of concept for in vitro preclinical trials.

Effect of Duloxetine on Urethral Resting Pressure and on Sphincter Contractility in Response to Coughing and Magnetic Stimulation in Healthy Women.

OBJECTIVES: As a proof-of-mechanism (POM) study of drugs developed to treat stress urinary incontinence (SUI) has not been conducted, this urodynamic study in healthy women was performed to determine an appropriate method to confirm POM, and to evaluate the effect of duloxetine, a serotonin and noradrenaline reuptake inhibitor, on urethral resting pressure and on sphincter contractility in response to coughing and magnetic stimulation. METHODS: The urethral pressure profiles at rest, during coughing and during sacral root magnetic stimulation (SMS), and the motor threshold (MT) for urethral sphincter contraction in response to transcranial magnetic stimulation (TMS) were measured before and 6 h after the administration of 40 mg duloxetine in 10 healthy female subjects. RESULTS: Oral administration of duloxetine significantly increased the mean and maximal urethral closure pressures at rest over the proximal and middle third of the urethra. During coughing, duloxetine marginally significantly increased the mean distal urethral pressure and significantly reduced the mean delay in the distal urethral pressure peak relative to the vesical peak. Although duloxetine did not change amplitudes of pressure spikes in response to SMS, this drug significantly lowered the MT in response to TMS. CONCLUSION: The proposed method for measuring the urethral resistance in healthy women can be used in POM studies of new drugs developed to treat SUI. CLINICAL TRIAL REGISTRATION NUMBER: UMIN000009096.

A comparison of the expression and contractile function of α1-adrenoceptors in seminal vesicle and vas deferens from normotensive and hypertensive rats.

Because hypertension related alterations occur in the properties of α(1)-adrenoceptor in several mammalian tissues and hypertension may impact ejaculatory function, we investigated hypertension related alterations in the functional, biochemical and molecular properties of α(1)-adrenoceptor in the rat seminal vesicle and vas deferens. Spontaneous seminal emission in male spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats was studied during the 3-day observation period. The characteristics of α(1)-adrenoceptor in the seminal vesicle and epididymal and prostatic portion of vas deferens of the two strains were determined using an isolated muscle bath, radioligand receptor binding and real-time reverse transcription-polymerase chain reaction techniques. SHRs had significantly higher serum testosterone than WKY rats. However, the daily mean number of ejaculatory plugs emitted and their dry weight in SHRs were significantly lower than those in WKY rats. Although there was no significant difference in the properties of α(1)-adrenoceptor in the prostatic portion of vas deferens between SHRs and WKY rats, the maximum contractile responses to phenylephrine, total α(1)-adrenoceptor density and expression of α(1A)-adrenoceptor mRNA were significantly higher in the seminal vesicle and epididymal portion of vas deferens of SHRs vs. WKY rats. Our data demonstrate the presence of hypertension related alterations in serum testosterone and in α(1)-adrenergic responsiveness of the rat seminal vesicle and vas deferens and suggest that ejaculatory function in SHRs does not mirror these hypertension related alterations.

Effects of age and hypertension on α1-adrenoceptors in the major source arteries of the rat bladder and penis.

α(1)-Adrenoceptors regulate blood pressure, regional vascular resistance and tissue blood flow. As aging and hypertension may impact pelvic arterial blood flow resulting in bladder and penile dysfunction, we investigated effects of age and hypertension on α(1)-adrenoceptors in the major source arteries of the rat bladder and penis. Using radioligand receptor binding, real-time reverse transcription-polymerase chain reaction (RT-PCR) and fluorescent microsphere infusion techniques, we compared 3 and 22-month-old male Fischer rats, and male normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs). Twenty-two-month-old rats and SHRs had significantly higher total α(1)-adrenoceptor density in the internal iliac artery and lower blood flow to the bladder and penis than 3-month-old and WKY rats, respectively. RT-PCR data showed an age and hypertension related increase in the expression of α(1B)-adrenoceptor mRNA in the internal iliac, vesical and internal pudendal arteries and a switch from α(1A) predominance in 3-month-old and WKY rats to α(1B)>α(1A) in 22-month-old rats and SHRs. Our data indicate the presence of age and hypertension related alterations in vascular α(1)-adrenoceptor subtype distribution and in blood flow to the rat bladder and penis. These findings suggest that pharmacological blockade of the vascular α(1B)-adrenoceptor, which could increase pelvic blood flow, may contribute to the improvement of bladder and penile dysfunctions in animal models for aging and hypertension.

The forefront for novel therapeutic agents based on the pathophysiology of lower urinary tract dysfunction: pathophysiology and pharmacotherapy of overactive bladder.

Overactive bladder (OAB) syndrome, which is characterized by a complex of storage symptoms (urinary urgency, frequency, nocturia, and urgency incontinence) is highly prevalent within the general population, causing major distress to patients in terms of their psychosocial and physical functioning. Muscarinic receptors of bladder smooth muscles are involved in both normal and disturbed bladder contraction. The muscarinic receptor functions may change in bladder disorders associated with OAB, implying that mechanisms, which normally have little clinical importance, may be up-regulated and contribute to the pathophysiology of OAB. In addition, several reports have suggested that various stimulations release many substances, including adenosine triphosphate, prostaglandins, nitric oxide, and acetylcholine, from bladder urothelium, which contribute to pathophysiology of the increased bladder sensation, OAB symptoms, and detrusor overactivity. Bladder urothelium possesses a non-neuronal cholinergic system and high density of muscarinic receptors. The roles and functions of the non-neuronal cholinergic system in OAB are now being evaluated. In the pharmacotherapy of OAB, antimuscarinic agents are the first choice drugs. Furthermore, new therapeutic targets at the levels of the urothelium, detrusor muscles, autonomic and afferent pathways, spinal cord, and brain are proposed. In this review, the pathophysiology of OAB, especially the role of non-neuronal acetylcholine, is discussed. In addition, new drugs with new action mechanisms will be introduced.

Identification of potential therapeutic targets in hypertension-associated bladder dysfunction.

OBJECTIVE: To investigate differential gene expression profiles in the bladder of spontaneously hypertensive rat (SHR), as the underlying mechanisms involved in hypertension-associated bladder dysfunction remain to be clarified. MATERIALS AND METHODS: SHR and normotensive Wistar-Kyoto (WKY) rats were distributed initially in three groups: group 1 received doxazosin (30 mg/kg/day); group 2 received nifedipine (30 mg/kg/day); and group 3 received the vehicle orally for 4 weeks. The alterations in gene expression levels of candidate genes identified by microarray analysis with potential biological relevance were verified by real-time reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Voiding frequency was significantly higher, and mean voided volume was significantly lower in untreated SHRs than untreated WKY rats. Microarray analysis revealed that 25 of the differentially expressed genes in untreated SHRs compared to untreated WKY rats were related to G(s), G(i), G(q) and G(12/13) signalling, calcium handling, ion transport and smooth muscle-related genes. Furthermore, RT-PCR data, in accord with the microarray analysis, indicated that untreated SHRs had lower mRNA expression levels of Adcy2, Adcy3, Rgs2, Rgs3, Rgs4 and Arhgdia, and higher mRNA expression levels of Arhgef1, Arhgef11, Arhgef12, Geft, Rock1 and Rock2 than untreated WKY rats. The differential alterations in the micturition patterns and in the expression of several genes related to G-protein signalling pathway observed in SHRs were attenuated by treatment with doxazosin, but not nifedipine. CONCLUSION: Our data suggest that differential alterations in the expression of several genes related to G(s), G(q) and G(12/13) signalling pathways in the SHR bladder might be important in hypertension-associated bladder dysfunction.

Neuronal Nitric Oxide Synthase Gene Transfer into the Rat Prostate Using In Vivo Electroporation.

OBJECTIVES: It has been reported that nitric oxide (NO) mainly contributes to prostate or urethral smooth muscles relaxation, and that nitrergic innervation and neuronal NO synthase (nNOS) levels are decreased in benign prostatic hyperplasia. The purpose of the present study was to evaluate the feasibility to gene therapy for benign prostatic hyperplasia by transferring nNOS gene into the rat prostate with in vivo electroporation (EP) procedure. METHODS: Male Sprague-Dawley rats were divided into four groups (sham, only EP, only nNOS injection, and nNOS gene injection with EP groups). Fifty micrograms of luciferase gene and nNOS expression vectors in 50 µL of K-PBS (potassium-phosphate buffered saline) were injected into the prostate. Immediately after the injection of these vectors, the vector injection points were electroporated by the two-square parallel electrodes. Two days after gene transfer, luciferase analysis and an immunohistochemical staining for nNOS were performed, and NO2 (-) /NO3 (-) (NOX ) release was measured using high-performance liquid chromatography coupled with the microdialysis procedure. RESULTS: The optimal electric pulse conditions were 50 V, 1 Hz and 10 msec. In vivo EP with these conditions showed the increase in the luciferase gene expression approximately 300-fold of the control group. In the nNOS gene injection with EP group, the marked nNOS immunoreactivity was observed, and NOX release was significantly higher, as compared to other groups. CONCLUSION: The results suggest that EP is a feasible technique for in vivo gene transfer into the rat prostate, and that the transferred nNOS gene functionally expresses and contributes to NO production.

Molecular mechanisms regulating urogenital expression of nitric oxide synthase in spontaneously hypertensive rats.

AIMS: Although doxazosin, but not nifedipine, can partially prevent a decrease in urogenital expression of nitric oxide synthase (NOS) in spontaneously hypertensive rats (SHRs), the mechanisms involved in the regulated expression of NOS are not known. Therefore, we identified differential gene expression profiles in SHRs to elucidate the molecular mechanisms regulating urogenital expression of NOS. MAIN METHODS: SHRs and normotensive Wistar-Kyoto (WKY) rats received doxazosin (30 mg/kg/day) or nifedipine (30 mg/kg/day) orally for 4 weeks. Microarray expression data of key transcripts were verified by real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. KEY FINDINGS: RT-PCR data, in accord with the microarray analysis, indicated that untreated SHRs had lower mRNA expression levels of cAMP responsive element binding protein 1 (Creb1) in the pelvic ganglion and vascular endothelial growth factor A (Vegfa) and kinase insert domain protein receptor (Kdr) in the penis, and higher mRNA expression levels of brain derived neurotrophic factor and neurotrophin 3 (Ntf3) in the bladder and Ntf3, Rho-kinases (Rock1 and Rock2) and caveolin 1 (Cav1) in the penis than untreated WKY rats. In SHRs, doxazosin and nifedipine caused a significant decrease in penile expression of Rock1 and Rock2, whereas the differential alterations in urogenital expression of Creb1, Vegfa, Kdr and Cav1 were attenuated by treatment with doxazosin, but not nifedipine. SIGNIFICANCE: Our data suggest that differential alterations in the expression of several genes related to pathways that mediate NOS expression in the urogenital tissues of SHRs, which can be attenuated by doxazosin treatment, may play an important role in regulating urogenital expression of NOS.

Short- and long-term effects of silodosin, a selective alpha 1A-adrenoceptor antagonist, on ejaculatory function in rats.

OBJECTIVE: To investigate the short- and long-term effects of silodosin, a selective alpha(1A)-adrenoceptor antagonist, on spontaneous seminal emission by isolated rats and on the properties of alpha(1)-adrenoceptor subtypes in the rat seminal vesicle, as silodosin produces a relatively high incidence rate of abnormal ejaculation and chronic administration of receptor antagonists causes an up-regulation in the targeted receptor. MATERIALS AND METHODS: Rats were treated with two doses (0.1 and 3 mg/kg/day) of silodosin orally for 3 or 30 days. Spontaneous seminal emission was studied during the 3-day observation period before completing treatment. The expression levels of alpha(1A), alpha(1B) and alpha(1D)-adrenoceptor mRNAs in the rat seminal vesicle and prostate were quantified by real-time reverse transcription-polymerase chain reaction using SYBR Green I. RESULTS: The administration of two doses of silodosin for 3 or 30 days caused a significant dose-dependent reduction in the number of ejaculatory plugs and in their dry weight. However, in rats receiving the low dose of silodosin the inhibitory effect of the drug on spontaneous seminal emission diminished significantly with chronic usage over time. Although short-term administration of silodosin did not affect expression levels of any alpha(1)-adrenoceptor subtype mRNAs in the rat seminal vesicle and prostate, long-term administration of silodosin caused a significant up-regulation in the mRNA expression of alpha(1A)-adrenoceptor in a tissue-dependent manner. CONCLUSION: Silodosin-induced up-regulation of alpha(1A)-adrenoceptor mRNA in the rat seminal vesicle might indicate potential differences in the inhibitory effect of this drug on ejaculatory function with chronic usage over time.

Differential effects of prazosin and naftopidil on pelvic blood flow and nitric oxide synthase levels in spontaneously hypertensive rats.

We compared the effects of two alpha(1)-adrenoceptor antagonists with different selectivity for the alpha(1)-adrenoceptor subtypes, prazosin and naftopidil, on pelvic blood flow and nitric oxide synthase (NOS) levels in the spontaneously hypertensive rat (SHR). SHRs and normotensive Wistar-Kyoto (WKY) rats were distributed initially in four groups: group 1 received prazosin, a subtype nonselective alpha(1)-adrenoceptor antagonist (2 mg/kg/day); group 2 received naftopidil, a selective alpha(1A/D)-adrenoceptor antagonist (10 mg/kg/day); group 3 received cyclazosin, a selective alpha(1B)-adrenoceptor antagonist (5 mg/kg/day); and group 4 received the vehicle orally for 4 weeks. Pelvic blood flow was determined by using a fluorescent microsphere infusion technique. Expression levels of nNOS and eNOS mRNAs in the rat genitourinary tissues were quantified by real-time reverse transcription polymerase chain reaction (RT-PCR) using SYBR Green I. The characteristics of alpha(1)-adrenoceptors in the rat iliac artery were determined by using radioligand receptor binding and real-time RT-PCR techniques. Untreated SHRs had lower blood flow to the ventral prostate, dorsolateral prostate, urinary bladder, and penis and lower mRNA expression levels of nNOS in the bladder and penis and eNOS in the penis than untreated WKY rats. Naftopidil had no significant effects on blood flow and NOS levels, whereas administration of prazosin and cyclazosin to the SHR caused a significant increase in blood flow to each tissue studied and a significant increase in expression levels of these genes. The density of total alpha(1)-adrenoceptors was significantly higher in iliac arteries of untreated SHRs than those of untreated WKY rats. RT-PCR data indicated that alpha(1B)-adrenoceptor mRNA was the significantly predominant gene transcript in iliac arteries of untreated SHRs. Our data show that prazosin, but not naftopidil, causes differential alterations in NOS levels in the SHR genitourinary tract, which could be due to increased pelvic blood flow resulting from inhibiting the vascular alpha(1B)-adrenoceptor. These findings may provide insight into the beneficial effects of subtype nonselective alpha(1)-adrenoceptor antagonists on prostate, bladder, and penile function, when used to treat symptoms of benign prostatic hyperplasia and elevated blood pressure.

Differential effects of diabetes induced by streptozotocin and that develops spontaneously on prostate growth in Bio Breeding (BB) rats.

We investigated molecular changes in the response to insulin in prostates of spontaneously developed (Bio Breeding) and streptozotocin (STZ)-induced diabetic rats that received sufficient amounts (euglycemic group), or suboptimal doses (hyperglycemic group) of insulin for 32 weeks, using Affymetrix GeneChip analysis of gene expression. Alterations in gene expression levels identified by microarray analysis, having potential biological relevance to prostate growth, were verified by real-time reverse transcription polymerase chain reaction (RT-PCR). A significant decrease in the weight of ventral prostate was observed in the hyperglycemic STZ-induced but not spontaneously developed diabetic group. Microarray analysis revealed that gene expression profiles were distinctly different in each region of the prostate, and that hyperglycemic diabetes in spontaneously developed and STZ-diabetic rats was associated with differential changes in the prostatic expression levels of 856 genes, of which 35 were related to cell growth, proliferation and death. RT-PCR data verified significant differences in the mRNA expression levels of Igfbp6, Tieg, and Clu between euglycemic and hyperglycemic groups, whereas expression levels of these genes in control and euglycemic diabetic groups were not significantly different. In ventral prostate, the mRNA expression levels of Igfbp6 and Tieg were significantly higher in the hyperglycemic STZ-induced diabetic than in the hyperglycemic spontaneously diabetic BBDP/Wor rats. Our data demonstrate that the diabetes induced by STZ in the BBDR/Wor rats affects prostate growth and the molecular response to insulin differently than that observed in BBDP/Wor rats that develop diabetes spontaneously.

Region and age dependent differences in alpha(1)-adrenergic responsiveness of rat seminal vesicle and vas deferens.

Because age dependent differences occur in the incidence of ejaculatory dysfunction with alpha(1)-adrenoceptor antagonists used to treat lower urinary tract symptoms secondary to benign prostatic hyperplasia, we investigated age related changes in the functional, biochemical and molecular properties of alpha(1)-adrenoceptor in the rat seminal vesicle and vas deferens. The characteristics of alpha(1)-adrenoceptor in the seminal vesicle and epididymal and prostatic portion of vas deferens of 3 and 22-month-old rats were determined using an isolated muscle bath, radioligand receptor binding and real-time reverse transcription-polymerase chain reaction techniques. Old rats had significantly higher body weight and lower testosterone than young rats. Although there was no significant age dependent difference in the properties of alpha(1)-adrenoceptor in the prostatic portion of vas deferens, the maximum contractile responses to phenylephrine, total alpha(1)-adrenoceptor density and mRNA expression of all 3 alpha(1)-adrenoceptor subtypes were significantly lower in the seminal vesicle and epididymal portion of vas deferens of 22 vs 3-month-old rats. Age dependent differences in the molecular, biochemical and functional properties of alpha(1)-adrenoceptors in the rat seminal vesicle and vas deferens may indicate potential differences in the response to alpha(1)-adrenoceptor antagonists with aging.

Effects of doxazosin on blood flow and mRNA expression of nitric oxide synthase in the spontaneously hypertensive rat genitourinary tract.

Hypertension may impact pelvic arterial blood flow resulting in reduction of nitric oxide synthase (NOS) levels. Although doxazosin, an alpha(1)-adrenoceptor antagonist, has been shown to improve erectile dysfunction as well as benign prostatic hyperplasia (BPH) and hypertension, it is not clear whether these improvements using doxazosin are primarily due to direct actions on the prostate, urinary bladder and penis, possibly via inhibition of vascular alpha(1)-adrenoceptors, or other sites of actions. Therefore, we investigated effects of doxazosin to the spontaneously hypertensive rat (SHR) on blood flow and NOS levels in the genitourinary tract. Four groups of rats were assessed: group 1, SHRs treated with doxazosin (30 mg/kg/day) for 4 weeks; group 2, SHRs treated with nifedipine (30 mg/kg/day) for 4 weeks; group 3, untreated SHRs; and group 4, untreated Wistar-Kyoto (WKY) rats. Blood flow to the ventral prostate, dorsolateral prostate, urinary bladder and penis was determined using a fluorescent microsphere infusion technique. Expression levels of nNOS and eNOS mRNAs were quantified by real-time RT-PCR using SYBR Green I. Blood flow to the ventral prostate, dorsolateral prostate, urinary bladder and penis was significantly lower in untreated SHRs than WKY rats. Treatment with doxazosin increased blood flow to each tissue studied in SHRs. RT-PCR data indicated that untreated SHRs had lower mRNA expression levels of nNOS in the bladder and penis and eNOS in the penis than WKY rats and that administration of doxazosin to the SHR caused an increase in expression levels of these genes, i.e., up-regulation of nNOS in the bladder and penis and eNOS in the penis. However, nifedipine had no significant effects on blood flow and NOS levels in the SHR genitourinary tract. Our data demonstrate that doxazosin treatment causes differential alterations in blood flow and NOS levels in the SHR genitourinary tract. These findings may provide insight into the beneficial effects of alpha(1)-adrenoceptor antagonists, on prostate, bladder and penile function, when used to treat symptoms of BPH and elevated blood pressure.