Efficacy and Safety of Mirodenafil Oro-Dispersible Film in Korean Patients with Erectile Dysfunction: A Double-Blind, Randomized, Placebo-Controlled, Parallel-Group, Multicenter, Phase IV Study.

PURPOSE: To investigate the efficacy, safety, and tolerability of oro-dispersible film (ODF) formulation of mirodenafil 50 mg and 100 mg for the treatment of patients with erectile dysfunction (ED) in Korea. MATERIALS AND METHODS: A multicenter, randomized, double-blind, placebo-controlled, parallel-group study of 129 subjects was performed. Subjects were randomized to either placebo or mirodenafil ODF 50 mg or 100 mg to be taken in an "on demand" manner for 8 weeks. The primary efficacy variable was the International Index of Erectile Dysfunction (IIEF)-5 questionnaire. The secondary efficacy variables comprised Sexual Encounter Profile questions 2 and 3 (SEP2 and SEP3), the Global Assessment Question (GAQ), and the Life Satisfaction Checklist (LSC). RESULTS: IIEF-5 was significantly increased in all groups after treatment. However, compared to the placebo group, only the mirodenafil ODF 100 mg group showed a significant difference. SEP2 and SEP3 were increased in both mirodenafil groups; however, the increase was not statistically significant for SEP2. In terms of GAQ and LSC, the mirodenafil ODF groups showed significant increases compared with the baseline. Most treatment-associated adverse events were mild and resolved spontaneously. CONCLUSIONS: Mirodenafil ODF is an effective and well-tolerated agent for the treatment of patients with ED in Korea.

Role of Prior Split Renal Function for Living Kidney Transplantation in Recipients and Donors.

PURPOSE: The purpose of this study was to determine the relationship between pre-operative donor split renal function (SRF) and the renal function outcome of donors and recipients after kidney transplantation (KT). METHODS: A total of 217 living KT cases were investigated. The estimated glomerular filtration rate (eGFR) change of recipients and donors, as well as graft survival, were analyzed based on the donor SRF. The difference in SRF (dSRF) in a donor was defined as follows: the SRF of the donated kidney minus the SRF of the remaining kidney determined by pre-operative 99mTc-diethylenetriaminepentaacetic acid in the donors. The dSRF was categorized into tertiles. RESULTS: The dSRF was not associated with the eGFR in recipients in any tertile at 6 or 12 months post-KT. The overall graft and patient survival did not differ significantly among tertiles. Donors in the high tertile, who donated kidneys with a higher SRF, showed a greater reduction in eGFR than did donors in the low and middle tertile after adjustment for function of the not-donated kidney (-34 ± 1.9 vs -28 ± 2.2, and -27 ± 1.3 mL/min/1.73 m2, P < .05). CONCLUSIONS: The dSRF did not affect the post-KT renal function or graft survival in recipients. However, the donors who donated the better functioning kidney had a poorer renal function after donation.

Influence of Daytime or Nighttime Dosing with Solifenacin for Overactive Bladder with Nocturia: Impact on Nocturia and Sleep Quality.

We compared changes in nocturia and sleep-related parameters between daytime and nighttime solifenacin dosing in patents with overactive bladder (OAB) and nocturia. We comparatively analyzed the data of a 12-week prospective, open-label, multicenter, randomized study. All 127 patients who presented to 5 centers in Korea for the treatment of OAB with nocturia between January 2011 and December 2013 were enrolled in this study. The patients were divided into 2 groups by medication timing: group 1, daytime (n = 62); and group 2, nighttime (n = 65). The International Prostate Symptom Score (IPSS), Overactive Bladder Symptom Score (OABSS), and Athens Insomnia Scale (AIS) were used to assess OAB symptoms and sleep quality. We evaluated the parameter changes before and 12 weeks after daytime or nighttime solifenacin administration. Baseline data, which included sex, age, body mass index (BMI), total AIS, IPSS, and OABSS, did not differ between the 2 groups. Total IPSS, OABSS, and total AIS significantly improved after solifenacin administration regardless of timing (P < 0.001). After solifenacin administration, the number of nocturia episodes decreased in the group 1 and 2 (P < 0.001). There were no significant intergroup differences in changes in AIS, IPSS, OABSS, and number of nocturia episodes 12 weeks after solifenacin administration. Treating OAB with solifenacin may improve nocturia and sleep quality, but advantages did not differ significantly by medication timing.

Incidental abnormal FDG uptake in the prostate on 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography scans.

18-fluoro-2-deoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) scans are commonly used for the staging and restaging of various malignancies, such as head and neck, breast, colorectal and gynecological cancers. However, the value of FDG PET/CT for detecting prostate cancer is unknown. The aim of this study was to evaluate the clinical value of incidental prostate 18F-FDG uptake on PET/CT scans. We reviewed 18F-FDG PET/CT scan reports from September 2009 to September 2013, and selected cases that reported focal/diffuse FDG uptake in the prostate. We analyzed the correlation between 18F-FDG PET/CT scan findings and data collected during evaluations such as serum prostate-specific antigen (PSA) levels, digital rectal examination (DRE), transrectal ultrasound (TRUS), and/or biopsy to confirm prostate cancer. Of a total of 18,393 cases, 106 (0.6%) exhibited abnormal hypermetabolism in the prostate. Additional evaluations were performed in 66 patients. Serum PSA levels were not significantly correlated with maximum standardized uptake values (SUVmax) in all patients (rho 0.483, p=0.132). Prostate biopsies were performed in 15 patients, and prostate cancer was confirmed in 11. The median serum PSA level was 4.8 (0.55-7.06) ng/mL and 127.4 (1.06-495) ng/mL in the benign and prostate cancer groups, respectively. The median SUVmax was higher in the prostate cancer group (mean 10.1, range 3.8-24.5) than in the benign group (mean 4.3, range 3.1-8.8), but the difference was not statistically significant (p=0.078). There was no significant correlation between SUVmax and serum PSA, prostatic volume, or Gleason score. 18F-FDG PET/CT scans did not reliably differentiate malignant or benign from abnormal uptake lesions in the prostate, and routine prostate biopsy was not usually recommended in patients with abnormal FDG uptake. Nevertheless, patients with incidental prostate uptake on 18F-FDG PET/ CT scans should not be ignored and should be undergo further clinical evaluations, such as PSA and DRE.

Primary androgen deprivation therapy for prostate cancer in koreans: a retrospective multicenter study.

PURPOSE: To evaluate the characteristics of patients who received primary androgen deprivation therapy (PADT) for prostate cancer and the clinical efficacy of this treatment. MATERIALS AND METHODS: Two hundred forty patients treated by PADT were reviewed. These patients could not receive definitive therapy owing to old age, patient need, and medical comorbidity. The patients were divided into three groups according to the extent of prostate cancer: localized, locally advanced, and metastatic. Then, prostate-specific antigen (PSA) progression in these groups was analyzed. RESULTS: The median age of the patients was 73.0 years, and the median pretreatment PSA level was 47.0 ng/mL. Of the patients, 91.7% were treated with combined androgen blockade, and 8.3% were treated with monotherapy. Clinical factors for PSA progression were a PSA nadir and a high clinical stage. Estimated PSA recurrence-free median survival time in each group was 57, 24, and 12 months, respectively. A PSA nadir of >0.2 ng/mL and metastatic stage were independent factors for expecting a poor response to PADT (hazard ratio 4.26, p<0.001; and 2.60, p<0.001). CONCLUSIONS: Patients with localized or locally advanced prostate cancer who did not receive definitive therapy had lower PSA progression rates than those at metastatic stage during PADT. Further, a PSA nadir of ≤0.2 ng/mL showed better progression-free survival. Therefore, PADT can be another therapeutic option in well-selected patients with localized or locally advanced prostate cancer and PSA change should be checked carefully.

Clinical Significance of Wnt/ß-Catenin Signalling and Androgen Receptor Expression in Prostate Cancer.

PURPOSE: To investigate the relationships among the Wnt/ß-catenin pathway, androgen receptor (AR), and clinicopathological factors in hormone-naïve prostate cancer. MATERIALS AND METHODS: This study was conducted with132 cases of hormone-naïve prostate cancer treated by prostatectomy and prostate needle biopsy. An immunohistochemical study using antibodies against ß-catenin, matrix metalloproteinase-7 (MMP-7), and the AR was performed. For the in vitro study, PC-3, LNCaP, 22Rv1, and DU145 cell lines were used. RESULTS: The clinical or pathological stage ware a localized cancer in 36 patients (27.3%), locally advanced cancer in 31 (23.5%), and metastatic cancer in 65 (49.2%). We detected increased ß-catenin, AR, and MMP-7 expression with a high Gleason grade, disease progression, and increasing serum prostate-specific antigen (PSA) levels (p<0.01). In Spearman's rank correlations, the expression of cytoplasmic ß-catenin, MMP-7, and the AR were found to be significantly positively correlated. In addition, the expression of ß-catenin, MMP-7, and the AR were significantly correlated with clinicopathological variables indicative of a poor prognosis. Forty-nine patients with primary androgen deprivation had short response durations from hormone therapy to PSA progression with elevated MMP-7 expression on the Kaplan-Meier curve (p=0.0036). CONCLUSIONS: These data show that an activated Wnt/ß-catenin pathway and AR expression in prostate cancer are correlated with metastasis and aggressiveness. In addition, the expression of MMP-7 protein, a target of the Wnt/ß-catenin pathway, is associated with PSA progression in prostate cancer patients undergoing primary hormone therapy.

Korean prostate cancer patients have worse disease characteristics than their American counterparts.

BACKGROUND: Although the PSA test has been used in Korea for over 20 years, the incidence of prostate cancer has risen, and the associated mortality has increased about 13-fold over the 20-year period. Also, several investigators have suggested that Asians in America are more likely to present with more advanced prostate cancer than Caucasians. We compared the characteristics of native Koreans and Americans (Caucasians and African- Americans) undergoing radical prostatectomies in Korea and the US. MATERIALS AND METHODS: Study subjects comprised patients at Korean and US hospitals from 2004 to 2012 who had undergone radical prostatectomies. We compared the characteristics of the subjects, including age, preoperative prostate-specific antigen (PSA) levels, body mass index (BMI), Gleason score, and pathological T stage. RESULTS: In total, 1,159 males (502 Koreans, 657 Americans) were included. The Korean and American patients had mean ages of 67.1 ± 6.6 and 59.2 ± 6.7 years, respectively. The mean preoperative PSAs were 15.4 ± 17.9 and 6.2 ± 4.6 ng/mL (p=0.0001) and the mean BMIs were 23.6 ± 2.6 and 28.7 ± 4.4 kg/m2 (p=0.0001), respectively. Pathological localized prostate cancer represented 71.7% of cases for Koreans and 77.6% for Americans (p=0.07). According to age, Koreans had higher T stages than Americans in their 50s (p=0.021) and higher Gleason scores than Americans in all age groups. According to PSA, Koreans had higher Gleason scores than Americans for PSA >10 ng/mL (p<0.05). According to prostate size and Gleason scores, Koreans had higher PSA values than Americans (p<0.01). CONCLUSIONS: These results show that Korean patients have elevated risk of malignant prostate cancers, as indicated by the significantly higher Gleason scores and PSAs, suggesting a need for novel prostate cancer treatment strategies in Korea.

Urologist's Practice Patterns Including Surgical Treatment in the Management of Premature Ejaculation: A Korean Nationwide Survey.

PURPOSE: According to previous studies, the prevalence of premature ejaculation (PE) in Korea ranges from 11.3% to 33%. However, the actual practice patterns in managing patients with PE is not well known. In this study, we have endeavored to determine how contemporary urologists in Korea manage patients with PE. MATERIALS AND METHODS: The e-mailing list was obtained from the Korean Urological Association Registry of Physicians. A specifically designed questionnaire was e-mailed to the 2,421 urologists in Korea from May 2012 to August 2012. RESULTS: UROLOGISTS IN KOREA DIAGNOSED PE USING VARIOUS CRITERIA: the definition of the International Society for Sexual Medicine (63.4%), Diagnostic and Statistical Manual of Mental Disorders (43.8%), International Statistical Classification of Disease, 10th edition (61.7%), or perceptional self-diagnosis by the patient himself (23.5%). A brief self-administered questionnaire, the Premature Ejaculation Diagnostic Tool, was used by only 42.5% of the urologists. Selective-serotonin reuptake inhibitor (SSRI) therapy was the main treatment modality (91.5%) for PE patients. 40.2% of the urologists used phosphodiesterase type 5 inhibitors, 47.6% behavior therapy, and 53.7% local anesthetics. Further, 286 (54.3%) urologists managed PE patients with a surgical modality such as selective dorsal neurotomy (SDN). CONCLUSIONS: A majority of Korean urologists diagnose PE by a multidimensional approach using various diagnostic tools. Most urologists believe that medical treatment with an SSRI is effective in the management of PE. At the same time, surgical treatment such as SDN also investigated as one of major treatment modality despite the lack of scientific evidence.

Urothelial carcinoma arising from a large ureteral polyp.

We report an unusual case of a urothelial tumor on a ureteral polyp without hydronephrosis. The patient was a 50-year-old male. He had experienced several episodes of gross hematuria. Cystoscopy revealed a tumor that periodically prolapsed into the bladder. The tumor had a smooth-surfaced stalk with an erythematous, edematous lesion at the end. Tomography showed a mass and filling defect at the left ureterovesical junction. The results of urine cytology tests were negative. After the tumor was identified as a urothelial carcinoma by frozen biopsy analysis, a ureteroscopic resection was performed. The final pathological diagnosis was urothelial carcinoma arising in a ureteral polyp. No recurrence of the tumor or polyp was observed at the 3-month follow-up. To our knowledge, this is the first report in the Korean population of a urothelial tumor arising from a ureteral polyp.

Prevalence of premature ejaculation in young and middle-aged men in Korea: a multicenter internet-based survey from the Korean Andrological Society.

In this study, we aimed to investigate the prevalence and perception of premature ejaculation (PE) in young and middle-aged Korean men. The study was conducted using an Internet-assisted questionnaire. A total of 2 037 Korean male adults, aged 20 years or older, were randomly sampled based on age and residency. The questionnaire developed by the PE Study Group of the Korean Andrological Society includes four categories (overall sexual function, symptoms, distress and treatment) with a total of 16 questions. For each question, symptoms were evaluated by a scale ranging from 0 to 10. Intravaginal ejaculation latency time was '5-10 min' in 38.6%, followed by 'longer than 10 min' in 29.9%, '2-5 min' in 23.6%, '1-2 min' in 5.4% and 'shorter than 1 min' in 2.5%. In our series, 27.5% of respondents reported having PE. Control over ejaculation within a recent 3-month period was 6.2 points on average. Respondent complaints of PE-related stress averaged 7.1 points and stress-related complaints from sexual partners averaged 7.1 points. The effect of PE on sexual life was 6.8 points. Of the respondents determined as having PE, 42.6% responded that they were inclined to receive treatment. Results from this study suggest that the prevalence of PE diagnosed by the respondent on his own was approximately 27.5% in young and middle-aged men in Korea. PE-related stress had a significant effect on the stress, sexual activity and quality of life of the respondent and his sexual partner.

Efficacy of udenafil for the treatment of erectile dysfunction up to 12 hours after dosing: a randomized placebo-controlled trial.

INTRODUCTION: Udenafil is a newly developed selective phosphodiesterase type 5 inhibitor for the treatment of men with erectile dysfunction (ED). AIM: To evaluate the efficacy of udenafil in treating ED for up to 12 hours after dosing. METHODS: This was a randomized, double-blind, placebo-controlled, parallel-group, fixed dose design, multicenter study. Following a 4-week nondrug baseline period, 104 men with ED of broad etiology and severity were randomized to one of two treatment groups: udenafil 100 mg or placebo. Participants were requested to attempt sexual intercourse at 12 hours after udenafil or placebo dosing during a 4-week treatment period. MAIN OUTCOME MEASURES: The primary efficacy variable was the response of patients to question 3 of the Sexual Encounter Profile (SEP Q3). The secondary efficacy measures were the response of patients to question 2 of the Sexual Encounter Profile (SEP Q2). Additional secondary efficacy measures included changes from baseline in the erectile function (EF) domain scores of the International Index of Erectile Function (IIEF) questionnaire. RESULTS: Of the 104 patients, 103 (50 in the udenafil group, 53 in the placebo group) completed the study. Udenafil significantly enhanced the rate of maintenance of erection (SEP Q3; placebo, 28.3% vs. udenafil, 54.7%; P < 0.0001). Significant change from baseline in the IIEF-EF domain was observed in the udenafil group (placebo, -0.58 ± 0.67; udenafil, 4.40 ± 0.84; P < 0.0001). For SEP Q2, there was no difference from baseline and no difference between the two groups. The overall adverse events rate was 11.3%. Most adverse events were mild or moderate in severity, and no serious adverse events were reported during the study and the follow-up period. CONCLUSIONS: Udenafil at 100 mg was effective for relieving ED for up to 12 hours after dosing. This duration of effectiveness could allow for flexibility and spontaneity in the sexual lives of patients.

Treatment preferences in men with erectile dysfunction: an open label study in Korean men switching from sildenafil citrate to tadalafil.

AIM: To evaluate patient preferences for sildenafil citrate or tadalafil (PDE-5 inhibitors available for the treatment of erectile dysfunction [ED]) and assess potential reasons for these preferences. METHODS: This open-label study was conducted on Korean men taking sildenafil, at least 6 weeks prior to study entry, for ED. Following screening, patients continued sildenafil treatment for 4 weeks, then after a 1-week washout period, switched to tadalafil for 8 weeks. Patients then continued with their treatment of choice during an extension phase. Psychosocial factors (time concern, spontaneity, sexual self-confidence) were evaluated using Psychological and Interpersonal Relationship Scales (PAIRS), while timing of dose to sexual attempt patterns were assessed from patient diaries. RESULTS: The present study enrolled 160 Korean men (mean age 55 years) with prior median sildenafil use of 585 days. During the extension phase, 73.7% of patients elected to take tadalafil, whereas 26.3% chose sildenafil (P < 0.001). After switching from sildenafil to tadalafil, mean PAIRS time concern scores decreased from 2.54 to 2.42 (P = 0.002), with no statistically significant differences observed between the sildenafil and tadalafil assessment phases in sexual spontaneity and self-confidence scores. Sexual attempts made > 4 h to =/< 36 h post-dose occurred in 4.5% of patients during the sildenafil assessment phase compared with 17.5% during the tadalafil assessment phase. CONCLUSION: After experiencing both sildenafil and tadalafil, the majority of patients exhibited a preference for tadalafil. This preference might be influenced by psychosocial factors, such as decreased time concerns, and a broader window of opportunity available for sexual activity.

[Construction of an explanatory model of female sexual dysfunction].

PURPOSE: Although concerns of female sexual dysfunction (FSD) are increasing in Korea, sexual dysfunction related factors are limited in research studies. The aim of this study was to develop an explanatory model that will further explain the continuously increasing female sexual dysfunction cases in Korea. METHODS: Survey visits were conducted to four hundred and eighty five women, over 25 years of age and presently residing in either urban or rural areas. All of them were analyzed using a structured questionnaire. A total of 8 instruments were used in this model. The analysis of data was done with both SPSS WIN for descriptive statistics and AMOS 5.0 for covariance structure analysis. RESULTS: As a result, variables that showed notably direct effects on FSD were: sexual concept (sexual attitude), sexual distress, and psychosocial health (depression, crisis, traumatic life events). On the other hand, variables such as age, educational level, economic status, and marital status showed indirect influences on health-promoting behaviors. CONCLUSION: By comprehensively addressing the factors related to sexual dysfunction, and comparing each influence, this study can contribute to designing an appropriate sexual dysfunction prevention strategy in tune with the particular characteristics and problems of a client.

Binding characteristics of [3H]delta(5)-androstene-3beta,17beta-diol to a nuclear protein in the rabbit vagina.

In this study, we investigated the binding characteristics of [3H]Delta(5)-androstene-3beta,17beta-diol to rabbit vaginal cytosolic and nuclear extracts and in freshly excised intact tissue strips. [3H]delta(5)-Androstene-3beta,17beta-diol bound to a protein(s) in the vaginal nuclear extract with high affinity (K(d)=3-5 nM) and limited capacity (50-100 fmol/mg protein). No specific binding was detected in the cytoplasmic extracts. Competitive binding studies showed that binding of [3H]delta(5)-androstene-3beta,17beta-diol was effectively displaced with unlabeled delta(5)-androstene-3beta,17beta-diol but not with dehydroepiandrosterone, testosterone, dihydrotestosterone, triamcinolone acetonide, or progesterone. However, estradiol at high concentrations partially displaced bound [3H]delta(5)-androstene-3beta,17beta-diol. Incubation of freshly excised vaginal tissue strips with [3H]delta(5)-androstene-3beta,17beta-diol in the absence or presence of excess unlabeled delta(5)-androstene-3beta,17beta-diol for 1h at 37 degrees C resulted in specific binding to a soluble macromolecule in the nuclear KCl extracts. In addition, quantitative measurement of estrogen receptor, androgen receptor and delta(5)-androstene-3beta,17beta-diol binding protein was performed by equilibrium ligand binding assays using extracts of distal vaginal tissue from intact animals or ovariectomized animals treated for 2 weeks with vehicle, estradiol, testosterone, or estradiol plus testosterone. These changes in steroid hormone levels resulted in opposing trends between the estrogen receptor and delta(5)-androstene-3beta,17beta-diol binding protein, suggesting that delta(5)-androstene-3beta,17beta-diol binding protein is regulated differently by the hormonal milieu than the estrogen receptor. These data suggest that rabbit vaginal tissue expresses a novel binding protein which specifically binds delta(5)-androstene-3beta,17beta-diol and is distinct from the androgen and estrogen receptors.

Effects of ovariectomy and estrogen replacement on basal and pelvic nerve stimulated vaginal lubrication in an animal model.

The goal of this study was to investigate the effects of ovariectomy and estrogen replacement on vaginal tissue integrity and vaginal lubrication in basal conditions and in response to pelvic nerve stimulation (PNS). Two weeks after ovariectomy, female New Zealand White rabbits were administered vehicle or estradiol (200 micrograms/day) for an additional 2 weeks. Ovariectomy caused significant vaginal atrophy and diminished vaginal lubrication in the basal state and after PNS, compared to intact controls. Estrogen replacement normalized lubrication values and tissue wet weight to control levels. In conclusion, vaginal tissue integrity and lubrication are diminished by ovariectomy and are normalized by estrogen replacement.

Selective P2Y2 receptor agonists stimulate vaginal moisture in ovariectomized rabbits.

OBJECTIVE: To determine the expression of P2Y(2) receptors in vaginal and cervical tissues and the effects of P2Y(2) receptor agonists INS45973 and INS365 on vaginal moisture. DESIGN: Pilot in vivo and histological study using animal subjects. SETTING: Experimental laboratory research. ANIMAL(S): Female New Zealand White rabbits were used for in vivo studies and female cynomolgus monkey (Macaca fascicularis) was used for in situ hybridization. INTERVENTION(S): Rabbits were kept intact or ovariectomized. Two weeks after ovariectomy, animals received daily vaginal instillation of vehicle or drugs for 16 days. MAIN OUTCOME MEASURE(S): Vaginal moisture was assessed in rabbits on 4 separate days during the treatment period. The P2Y(2) receptor mRNA distribution was assessed by in situ hybridization of monkey vagina and cervix. RESULT(S): Compared to control, vaginal moisture was significantly diminished in ovariectomized animals treated with vehicle. INS365 (8.1%) and INS45973 (0.9%) increased vaginal moisture in ovariectomized animals to levels that were comparable to or significantly higher than control animals, respectively. In situ hybridization studies indicated that P2Y(2) receptor mRNA was localized to endocervical and cervical gland, epithelium, and stratified squamous epithelium of the vagina. CONCLUSION(S): INS45973 and INS365 may interact with P2Y(2) receptors in the cervix and vagina to stimulate vaginal moisture in the estrogen (E)-deprived state. The P2Y(2) receptor agonists provide a potential nonhormonal alternative for treating vaginal dryness in postmenopausal women.

Expression of functional prostaglandin D (DP) receptors in human corpus cavernosum smooth muscle.

Prostaglandin D(2) (PGD(2)) binds to specific G-protein coupled receptors (DP) and induces smooth muscle relaxation by stimulating the synthesis of intracellular cAMP. In this study, we examined the role of PGD(2) and DP receptors in regulating human penile smooth muscle contractility. We determined that human corpus cavernosum tissue and smooth muscle cells in culture expressed functional DP receptor and lipocalin-like prostaglandin D synthase by reverse-transcribed polymerase chain reaction (RT-PCR). Functional PGD synthase activity was confirmed by the synthesis of PGD(2) in human corpus cavernosum smooth muscle cells upon addition of exogenous arachidonic acid. Organ bath preparations of human corpus cavernosum tissue strips, contracted with phenylephrine, relaxed in a dose-dependent fashion to either PGD(2) or the DP selective agonist BW245C. Cultures of human corpus cavernosum smooth muscle cells treated with BW245C showed a two-fold increase in cAMP synthesis. These data are consistent with the expression of functional DP receptors in human corpus cavernosum. This suggests the presence of an intact prostanoid autocrine system that may play a role in regulating penile erectile function.

Effects of ovariectomy and estrogen and androgen treatment on sildenafil-mediated changes in female genital blood flow and vaginal lubrication in the animal model.

OBJECTIVE: Our purpose was to investigate the effects of ovariectomy and estradiol and testosterone treatment on sildenafil- induced changes in genital hemodynamics and vaginal lubrication. STUDY DESIGN: Female New Zealand White rabbits were either kept intact or underwent ovariectomy. Two weeks after ovariectomy, animals were treated with vehicle, testosterone, or a combination of estradiol and testosterone for 14 days. Genital hemodynamics and vaginal lubrication were recorded at the end of the treatment period. RESULTS: Ovariectomy caused a marked decrease in vaginal lubrication but did not significantly alter genital hemodynamics. In contrast to testosterone treatment of ovariectomized animals, estradiol treatment significantly increased genital blood flow and vaginal lubrication above that observed in control animals. Sildenafil administration caused a significant increase in genital hemodynamics irrespective of the hormonal status. CONCLUSION: This study suggests that estradiol but not testosterone modulates genital hemodynamics and that sildenafil enhances genital blood flow irrespective of hormonal status.

Biochemical and functional characterization of alpha-adrenergic receptors in the rabbit vagina.

Vascular and non-vascular smooth muscle within the vagina mediate important physiological changes during sexual arousal in women. In this study, we have characterized alpha-adrenergic receptors (AR) in rabbit vagina by assessment of radioligand binding, contractility of isolated tissue strips and genital hemodynamics. [3H]Prazosin and [3H]RX821002 (alpha-1 and alpha-2 AR selective antagonists) bound to rabbit vaginal membrane preparations with high affinity and limited capacity. Competition binding assays using both non-selective and subtype selective ligands for AR (phentolamine, prazosin, delequamine, rauwolscine and UK14304) further confirmed the presence of alpha-1 and alpha-2 AR in vaginal tissue. In organ bath preparations of vaginal tissue strips, norepinephrine-induced contraction was attenuated by alpha-1 and alpha-2 AR antagonists (prazosin, tamsulosin, delequamine and phentolamine). In anesthetized rabbits, intravaginal injection of the alpha-1 AR selective antagonist REC 15/2615 (50 and 100 microg/kg) caused a 2 to 3-fold increase in genital tissue oxyhemoglobin (OHb) concentration. Similar increases in tissue OHb were observed with intravaginal injection of phentolamine (500 microg/kg) or a tri-mixture of vasodilators (PGE1, papaverine, phentolamine). REC 15/2615, phentolamine or the tri-mixture also enhanced the amplitude and/or duration of change in genital tissue OHb after pelvic nerve stimulation. Thus, vaginal tissue expresses functional alpha-1 and alpha-2 AR, which modulate vaginal smooth muscle contractility and genital engorgement.

Efficacy of vardenafil and sildenafil in facilitating penile erection in an animal model.

Vardenafil and sildenafil are potent and specific phosphodiesterase type 5 (PDE 5) inhibitors. In human penile cavernosal smooth muscle cells, we have previously shown that vardenafil has a lower biochemical inhibition constant (Ki) than sildenafil. In this study, we compared the efficacy of vardenafil and sildenafil in facilitating penile erection in a rabbit model. Penile erections were elicited by submaximal (2.5 or 6 Hz) pelvic nerve stimulation (PNS) repeated every 5 minutes for 30 minutes with or without intravenous (i.v.) administration of vardenafil (1-30 microg/kg) or sildenafil (10-30 microg/kg). Erectile response was assessed by continuously recording intracavernosal pressure (ICP) and systemic arterial pressure (SAP). All data were expressed as a ratio of ICP:SAP. I.v. administration of either PDE 5 inhibitor facilitated PNS-induced erection and increased ICP:SAP in a dose-dependent manner, reaching peak response at approximately 5 minutes. However, the threshold dose at which facilitation of erection occurred was lower for vardenafil (3 microg/kg) than for sildenafil (10 microg/kg). At the 10-microg/kg dose (i.v.), the response duration was significantly greater with vardenafil (169 +/- 23 seconds) than with sildenafil (137 +/- 31 seconds). Direct intracavernosal (i.c.) injection of 1-30 microg/kg vardenafil or sildenafil also caused dose-dependent increases in ICP:SAP in the absence of PNS. Response durations increased in a dose-dependent manner and lasted more than 5 times that of i.v. drug administration coupled with PNS. Irrespective of the route of administration (i.c. or i.v.), at equivalent doses, vardenafil was significantly more efficacious than sildenafil in facilitating pelvic nerve-mediated penile erection and in eliciting erection in the absence of PNS. The increases in ICPs occurred more quickly, were of larger magnitude, and were sustained for longer durations for vardenafil than for sildenafil. On the basis of the biochemical data and physiological responses from this study, further clinical evaluation of vardenafil as treatment for erectile dysfunction is warranted.