Tadalafil is efficacious in Black American and Hispanic men with erectile dysfunction: results from multiple observations in men with erectile dysfunction in national tadalafil study in the US (MOMENTUS)

To show that tadalafil is efficacious in Black American and Hispanic men with erectile dysfunction (ED) and efficacy is noninferior to that in Caucasian men. Multiple observations in men with ED in national tadalafil study in the US, a multicenter, open-label study, assessed the efficacy of tadalafil 20 mg taken as needed (maximum one dose/day before sexual activity) for 12 weeks by patients with ED in various populations. This analysis focuses on three groups: Caucasian (Reference group), Black American, and Hispanic men. Primary measurement of efficacy was change from baseline in erectile function (EF) domain of the International Index of Erectile Function (IIEF) and the primary analysis was whether efficacy in Black American and Hispanic groups was noninferior to efficacy in the Caucasian group. Secondary efficacy measures included sexual encounter profile (SEP), IIEF intercourse satisfaction (IS) and overall satisfaction (OS) domains, Global Assessment Question (GAQ), and Psychological and Interpersonal Relationship Scale (PAIRS). Safety was assessed from adverse events (AEs) reported by all enrolled patients. The increase in IIEF EF domain score (>or=9.5) from baseline for each group was statistically significant (P<0.001) and clinically relevant. Efficacy of tadalafil in Black American and Hispanic patients was noninferior to the Caucasian group. IS and OS domains of IIEF had a statistically significant increase from baseline (P<0.001). Change from baseline in positive responses to SEP questions for each group was significant (P<0.001). At least 77% of intercourse attempts were successful over various time intervals up to 36 h postdose. At least 88% of patients in the various groups had a positive response to GAQ1. Improvement from baseline in Sexual Self-Confidence and Spontaneity domains of PAIRS was statistically significant (P<0.001). A low number of AEs and a low AE-related discontinuation rate (2.3%) were reported in all groups. Tadalafil 20 mg was as efficacious in Black American and Hispanic men with ED as in Caucasian patients and was well tolerated.

Effects of ovariectomy and steroid hormones on vaginal smooth muscle contractility

The role of steroid hormones in regulating vaginal smooth muscle contractility was investigated. Rabbits were kept intact or ovariectomized. After 2 weeks, animals were continuously infused with vehicle or supraphysiological levels of testosterone (100 microg/day), or estradiol (200 microg/day), for an additional 2 weeks. The distal vaginal tissue was used to assess contractility in organ baths and changes in tissue structure were assessed by histology. Ovariectomized animals infused with vehicle exhibited significant atrophy of the muscularis and decreased epithelial height, resulting in thinning of the vaginal wall. Estradiol infusion increased epithelial height, comparable to that of intact animals, but only partially restored the muscularis layer. In contrast, testosterone infusion completely restored the muscularis layer, but only partially restored the epithelial height. In vaginal tissue strips contracted with norepinephrine and treated with bretylium, electrical field stimulation (EFS) caused frequency-dependent relaxation that was slightly attenuated with vehicle, significantly inhibited with estradiol and significantly enhanced with testosterone. VIP-induced relaxation was slightly attenuated in tissues from vehicle and estradiol-infused groups, but was enhanced in tissues from testosterone-infused animals. Contraction elicited by EFS or exogenous norepinephrine was not significantly altered with ovariectomy or steroid hormone infusion when data were normalized to potassium contraction. However, the tissue from testosterone-infused animals developed significantly greater contractile force to norepinephrine. These observations suggest that steroid hormones may be important regulators of vaginal tissue structure and contractility.

Role of the nitric oxide-cyclic GMP pathway in regulation of vaginal blood flow

The regulatory role of nitric oxide (NO) in vaginal perfusion remains unclear. We used specific inhibitors of enzymes in the NO-cyclic GMP (NO-cGMP) pathway and investigated their effects on vaginal blood flow in the rabbit. NO synthase (NOS) activity was similar in both the proximal and distal rabbit vagina; whereas, arginase activity was 3.4-fold higher in the distal vagina. Intravenous administration of the NOS inhibitor L-NAME resulted in a 66% reduction in genital tissue oxyhemoglobin and a 53% reduction in vaginal blood flow. This attenuation occurred despite a 20-30% increase in systemic arterial pressure. The arginase inhibitor ABH caused a 2.1-fold increase in genital tissue oxyhemoglobin and 34% increase in vaginal blood flow. The guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one and the phosphodiesterase type 5 inhibitor sildenafil caused in a 37% reduction and a 44% increase in vaginal blood flow, respectively. These observations suggest that the NO-cGMP pathway is an important regulator of vaginal hemodynamics.

The ‘effectiveness’ scale—therapeutic outcome of pharmacologic therapies for ED: an international consensus panel report

Despite availability of outcome measures and scales for assessing erectile dysfunction (ED) treatment efficacy, guidelines are not available for assessing broader therapeutic outcomes or defining treatment failure in ED. An International Consensus Advisory Panel was convened to develop guidelines, definitions and a new algorithm for evaluating treatment effectiveness in ED. These new guidelines are recommended for use in both research and clinical practice. A multidisciplinary, international panel, consisting of 11 senior researchers and clinicians, was convened to address pertinent issues concerning therapeutic outcome assessment for ED. The panel utilized a modified Delphi method of consensus development and proposed a new model for outcomes assessment. This model is inherently testable, using existing instruments and current methods of assessment. Following a comprehensive literature review and discussion, the Panel recommended adoption of a new treatment effectiveness conceptual framework or theoretical model for assessing therapeutic outcomes in ED. Treatment effectiveness is presumed to be a combined function of two other factors, treatment response and treatment satisfaction. Treatment response is based on the combined assessment of efficacy and tolerability, and treatment satisfaction on the combined assessment of patient and partner satisfaction. Taken together, these two domains define an overall domain of treatment effectiveness. This therapeutic index would be derived by independently assessing treatment efficacy and satisfaction by means of event logs, questionnaires or the more typical patient interview methods. In conclusion, the Ad Hoc Advisory Consensus Panel recommends adoption of a new framework or conceptual model for conducting ED outcome trials or clinical research. The concept of 'treatment effectiveness' is proposed as a new 'umbrella concept' or distal outcome to be evaluated.

Serum androgen levels in healthy premenopausal women with and without sexual dysfunction: Part A. Serum androgen levels in women aged 20–49 years with no complaints of sexual dysfunction

Androgen insufficiency is a recognized cause of sexual dysfunction in men and women. Age-related decrements in adrenal and gonadal androgen levels also occur naturally in both sexes. At present, it is unclear if a woman's low serum androgen level is a reflection of the expected normal age-related decline or indicative of an underlying androgen-deficient state. We studied premenopausal women with no complaints of sexual dysfunction to help define a normal female androgen profile. In all, 60 healthy, normally menstruating women, ages 20-49 y, were studied. The Abbreviated Sexual Function Questionnaire was administered along with a detailed interview. Radioimmunoassay measurements of morning serum testosterone (T), free testosterone (fT), dehydroepiandrosterone-sulfate (DHEAS), sex hormone-binding globulin (SHBG), and free androgen index (FAI) were measured during days 8-15 of the menstrual cycle. In women 20-49 y old without complaints of sexual dysfunction, serum androgen levels exhibit a progressive stepwise decline. Comparing values obtained in women age 20-29 y to those obtained in women 40-49 y, specific hormone decrements were DHEAS 195.6-140.4 microg/dl, serum T 51.5-33.7 ng/dl, fT 1.51-1.03 pg/ml. SHBG did not change significantly in women in this age group. The FAI reflected the age-related decrease in female androgen levels. The framework for the development of a female androgen profile in women with no complaints of sexual dysfunction has been established, and an age-related decrease in testosterone and its adrenal precursor, DHEAS, has been demonstrated. The FAI mirrors these decreases and its usefulness in clinical practice is confirmed. A precipitous decline in all androgens occurs after the decade of the 20s, yet SHBG does not show a significant change throughout the premenopausal years.

Serum androgen levels in healthy premenopausal women with and without sexual dysfunction: Part B: Reduced serum androgen levels in healthy premenopausal women with complaints of sexual dysfunction

Androgen insufficiency has been associated with decreased libido and arousal in postmenopausal women, but rarely has been evaluated in healthy premenopausal women. In all, 32 healthy premenopausal women were enrolled in this study, 18 with one or more complaints of sexual dysfunction and 14 without. Assays of ovarian and adrenal androgens were measured before and after ACTH stimulation. The women with complaints of sexual dysfunction had significantly lower adrenal androgens than did the control women. There were no differences in the basal ovarian androgens or cortisol levels. After ACTH, both groups stimulated cortisol as well as adrenal and ovarian androgens. In conclusion, premenopausal women with complaints of sexual dysfunction had lower adrenal androgen precursors and testosterone than age-matched control women without such complaints. Further study is required to determine how lower adrenal androgens contribute to female sexual dysfunction.

Sex steroid hormones differentially regulate nitric oxide synthase and arginase activities in the proximal and distal rabbit vagina

Nitric oxide synthase (NOS) and arginase have been shown to regulate nitric oxide (NO) production reciprocally in genital tissues. In animal models, NO is an important regulator of vaginal blood flow and vaginal wall contractility. In this study, we investigated the modulation of NOS and arginase activities by estrogens and androgens in the proximal and distal rabbit vagina. In intact control animals, total NOS activity was higher in the proximal (528+/-78 pmol/mg protein) than the distal (391+/-44 pmol/mg protein) vagina. However, arginase activity was higher in the distal (206+/-8 nmol/mg protein) than the proximal (64+/-5 nmol/mg protein) vagina. Ovariectomy enhanced NOS activity in the proximal but not distal vagina with concomitant decrease in arginase activity in both the proximal and distal vagina. In ovariectomized rabbits, replacement with 5alpha-dihydrotestosterone (DHT) or Delta5-androstenediol (Adiol) increased NOS activity beyond that observed in ovariectomized rabbits receiving vehicle. In contrast, DHT and Adiol treatment reduced arginase activity more than that of the ovariectomized rabbits receiving vehicle. Testosterone exhibited inconsistent effects on NOS and arginase activity in the distal and proximal vagina. Estradiol replacement in ovariectomized animals reduced NOS activity in the proximal vagina down to levels that were comparable to intact control animals. However, estradiol positively modulated arginase activity in the distal vagina. Western blot analyses indicated that in the proximal vagina, neural NOS protein levels paralleled the changes observed in enzyme activity. These observations suggest that steroid hormones differentially regulate NOS and arginase activities of the proximal and distal regions of the vagina. Although estrogen treatment reduced total NOS activity in proximal vagina, estrogens are known to enhance vaginal blood flow. This paradoxical observation may be explained by differential regulation of n-NOS and e-NOS in the proximal and distal vagina. We suggest that changes in vaginal blood flow and compliance may depend on the endocrine status and the levels of circulating androgens and estrogens.

Lower extremity above-knee prosthesis-associated erectile dysfunction

Blunt pelvic and perineal trauma has been previously reported to result in site-specific veno-occlusive dysfunction and/or site-specific cavernosal artery insufficiency. We herein describe a case of erectile dysfunction in a young previously potent amputee. We postulate that the erectile dysfunction is associated with a newly described form of blunt trauma, that is, site-specific compression from a perineal weight-bearing lower extremity above-knee prosthetic device. It is hypothesized that when the force exerted by the above-knee prosthesis is directed medially towards the ischiopubic ramus, the penile crura and common penile arterial blood supply become susceptible to crush-like injury, since they are in fixed anatomic locations in the perineum sandwiched between the compressive force and the bone. Clinical evaluation of the erectile dysfunction in this patient revealed site-specific corporal veno-occlusive dysfunction and site-specific common penile arterial occlusive pathology in the precise region of the contact of the above-knee prosthesis with the perineum. Further research is needed in above-knee prosthesis design to prevent erectile dysfunction.

Duplex Doppler ultrasound assessment of clitoral hemodynamics after topical administration of alprostadil in women with arousal and orgasmic disorders

There are limited hemodynamic data in women with arousal or orgasmic disorders and even fewer normative control hemodynamic data in women without sexual dysfunction. In addition, there is limited experience with topical vasoactive agents (used to maximize genital smooth muscle relaxation) applied to the external genitalia during hemodynamic evaluations. The aim of this study was to report duplex Doppler ultrasound clitoral cavernosal arterial changes before and after topical PGE-1 (Alprostadil) administration in control women and in patients with arousal and orgasmic sexual disorders. We found that women with sexual arousal and orgasmic disorders had significantly (p < 0.05) diminished clitoral peak systolic and end diastolic velocity responses compared to controls. Further research is needed to establish the diagnostic role of topical vasoactive agents in the hemodynamic evaluation of women with sexual dysfunction.

Report of the American Foundation for Urologic Disease (AFUD) Thought Leader Panel for evaluation and treatment of priapism

PURPOSE

Patients with priapism often develop permanent erectile dysfunction and personal sexual distress. This report is intended to help educate the public by reviewing the varied definitions and classifications of priapism and limited literature reports of pathophysiology, diagnosis and treatment outcomes of priapism. The AUA priapism guidelines committee is responsible for creating consensus as to appropriate individual patient management of priapism by physicians.

MATERIALS AND METHODS

A multidisciplinary panel, consisting of 19 thought leaders in priapism, was convened by the Sexual Function Health Council of the American Foundation for Urologic Disease to address pertinent issues concerning the role of the urologist, primary care providers and other health care professionals in the education of the public regarding management of men with priapism. The panel utilized a modified Delphi method and built upon the peer review literature on priapism.

RESULTS

The Thought Leader Panel recommended adoption of the definition of priapism as a pathological condition of a penile erection that persists beyond or is unrelated to sexual stimulation. Priapism is stressed to be an important medical condition that requires evaluation and may require emergency management. The classification system is categorized into ischemic and non-ischemic priapism. Essential elements of the ischemic classification are the inclusion of: (i) clinical characteristics of pain and rigidity; (ii) diagnostic characteristics of absence of cavernosal arterial blood flow; (iii) pathophysiological characteristics of a closed compartment syndrome; (iv) a time limit of 4 h prior to emergent medical care; and (v) a description of the potential consequences of delayed treatment. Essential elements of the non-ischemic classification are the inclusion of: (i) clinical characteristics of absence of pain and presence of partial rigidity; (ii) diagnostic and pathophysiological characteristics of unregulated cavernosal arterial inflow; and (iii) the need for evaluation but emphasizing the lack of a medical emergency. The panel recommended adoption of a rational management algorithm for the assessment and treatment of priapism where the cornerstone of initial assessment includes a careful clinical history, a focused physical examination and selected laboratory and/or radiologic tests. The panel recommended that specific criteria and clinical profiles requiring specialist referral should be identified. The panel further recommended that patient (and partner) needs and education concerning priapism should be addressed prior to therapeutic intervention, however only in the case of chronic management or post acute presentation evaluation should this delay intervention. Treatment goals to be discussed include management of the priapism with concomitant prevention of permanent and irreversible erectile dysfunction and associated psychosocial consequences. The panel recommended that when specific therapies for priapism are required, a step-care treatment approach based upon reversibility and invasiveness should be followed.

CONCLUSIONS

The Thought Leader Panel calls for research to expand our understanding of the prevalence and diagnosis of priapism and education to create awareness among the public of the potential urgency of this condition. Critical areas to be addressed include the multiple pathophysiologies of priapism as well as multi-institutional trials to objectively assess safety and efficacy in the various treatment modalities.

Hemodynamic evaluation of the female sexual arousal response in an animal model

The goal of this study was to assess the utility of existing and new techniques for characterizing and measuring hemodynamic changes in the vagina and clitoris in response to pelvic nerve stimulation (PNS) in an animal model. Using female New Zealand White rabbits, we measured the following parameters before, during, and after PNS at 4, 16, and 32 hertz (Hz): clitoral hemoglobin (Hb) content by laser oximetry, clitoral blood flow by laser Doppler flowmetry, vaginal luminal pressure of upper and lower segments, and clitoral intracavernosal pressure. Clitoral tissue concentrations of total and oxygenated hemoglobin (oxy-Hb) increased in a frequency-dependent manner while deoxygenated hemoglobin (deoxy-Hb) concentration decreased. The duration of the responses at 16 and 32 Hz were significantly greater than at 4 Hz. Clitoral blood flow increased significantly only at 32 Hz with a prolonged response duration, relative to 4 Hz. PNS caused vaginal luminal pressure changes that were highly variable, but qualitatively different, between the upper and lower regions. Clitoral intracavernosal pressure did not change significantly in response to PNS. Measurement of changes in tissue Hb content by the novel technique of laser oximetry provides a direct assessment of blood flow in a noninvasive manner and may prove to be a powerful tool in evaluating hemodynamic aspects of the female genital sexual response.

Experimental models for the investigation of female sexual function and dysfunction

There have been limited anatomic and physiological investigations of the female sexual arousal response. A broader understanding of the physiologic mechanisms of female sexual arousal function is required to improve the management of women with sexual dysfunction. Three experimental test systems have been developed to understand better the biochemical and physiological mechanisms of female sexual arousal response. An in vivo animal model was developed to record physiological and hemodynamic changes in the clitoris and vagina following pelvic nerve stimulation and administration of vasoactive agents and physiological modulators. In vitro organ baths of clitoral and vaginal tissue were utilized to investigate mechanisms involved in the regulation of smooth muscle contractility. In addition, primary cell cultures of human and animal clitoral and vaginal smooth muscle cells were developed to investigate signal transduction pathways modulating smooth muscle tone. In vivo studies revealed hemodynamic changes in vagina and clitoris in response to pelvic nerve stimulation, vasodilators and physiological modulators. Organ bath studies have demonstrated that clitoral and vaginal smooth muscle tone is affected by non-adrenergic and non-cholinergic neurotransmitters, and the presence of functional alpha 1 and alpha 2 adrenergic receptors in these tissues has been established through biochemical studies. These changes are regulated by the tone of vascular and non-vascular smooth muscle in the vagina and clitoris. Primary cell culture studies have suggested that several physiological modulators such as vasoactive intestinal polypeptide (VIP), nitric oxide (NO), and prostaglandin E (PGE) regulate vaginal smooth muscle contractility. Data from experimental models have provided a preliminary understanding of the mechanisms of the female sexual arousal response.

Unilateral renal agenesis associated with congenital bilateral absence of the vas deferens: phenotypic findings and genetic considerations

An association between congenital bilateral absence of the vas deferens (CBAVD), normal renal anatomy and cystic fibrosis (CF) gene mutations is well established (CF/CBAVD). We postulate that unilateral renal agenesis (URA) and CBAVD (URA/CBAVD) may have a non-CF mutation-mediated genetic basis that leads to abnormal development of the entire mesonephric duct at a very early stage in embryo development (< or =7 weeks). The physical, laboratory and radiographic findings of men with URA/CBAVD (n = 17) and CF/CBAVD (n = 97) were compared; the fertilization and pregnancy rates in the URA/CBAVD population calculated, and the incidence of renal agenesis in immediate family members and offspring of men with URA/CBAVD analysed. No statistical differences could be identified within any of the above comparisons. The fertilization rate for the URA/CBAVD group was 58.2 +/- 26.3%. Eight infants and two fetuses had normal renal anatomy, while one terminated male fetus had bilateral renal and vasal agenesis. Thirty first-order relatives had normal renal units. Anatomical expression of the reproductive ductal derivatives in men with URA/CBAVD and CF/CBAVD was similar, but the phenotypic outcome of the renal portion of the mesonephric duct was different. The potential for transmission of this fatal anomaly reinforces the need for prenatal ultrasounds with all pregnancies involving URA/CBAVD men.

Possible role of Na(+)-K(+)-ATPase in the regulation of human corpus cavernosum smooth muscle contractility by nitric oxide

1. This study was designed to determine the role of sodium-potassium adenosine triphosphatase (Na(+)-K(+)-ATPase) in the regulation of human corpus cavernosum smooth muscle contractility by nitric oxide (NO). In addition, we determined if the modulation of Na(+)-K(+)-ATPase activity by NO is dependent on the increase in intracellular cyclic GMP concentration. 2. The effect of NO donors, sodium-nitroprusside (SNP) and S-nitroso-glutathione (S-NO-Glu), and a permeable cyclic GMP analogue, 8-bromo-cyclic GMP, on Na(+)-K(+)-ATPase activity (measured as ouabain-sensitive 86Rb-uptake) was studied in human cultured corpus cavernosum smooth muscle cells (HCCSMC). In addition, the effect of the cyclic GMP lowering agent, methylene blue, on NO-induced increase in Na(+)-K(+)-ATPase activity was studied. 3. SNP (1 microM) caused time-dependent increases in ouabain-sensitive Rb-uptake (33-72%) over 2-20 min in HCCSMC. The stimulation of ouabain-sensitive Rb-uptake by SNP was concentration-dependent (30 and 102% with 0.1 and 1 microM SNP, respectively). Similarly, significant increases in ouabain-sensitive Rb-uptake were obtained with 1 and 10 microM S-NO-Glu. In contrast, incubation of HCCSMC with 8-bromo-cyclic GMP (100 microM) did not increase ouabain-sensitive Rb-uptake. 4. S-NO-Glu induced-increase in intracellular cyclic GMP synthesis, but not the increase in ouabain-sensitive Rb-uptake, was completely inhibited by methylene blue in HCCSMC. 5. The Na(+)-K(+)-ATPase inhibitor, ouabain, caused a concentration-dependent increase in tension (0.5 to 2 fold) in tissues contracted with 15 mM KCl. SNP and S-NO-Glu caused a concentration-dependent relaxation (concentration required to cause half maximal relaxation (ED50) = 0.04 and 0.2 microM, respectively) of HCC strips contracted with 15 mM K+. Ouabain (0.1 to 10 microM) inhibited the response to SNP and S-NO-Glu by shifting the concentration-response curves to the right and preventing full smooth muscle relaxation.6. These results indicate that the activity of Na+-K+-ATPase modulates the contractility of HCC smooth muscle, and that NO stimulates Na+-K+-ATPase activity in HCCSMC independently of its ability to increase the intracellular cyclic GMP concentration. They also suggest that stimulation of Na+-K+-ATPase activity plays an important role in NO-induced relaxation of HCC smooth muscle