The regulatory effect of sex steroids on the RhoA/ROCK pathway in the rat distal vagina.

BACKGROUND: Sex steroids have been demonstrated as important modulators of vaginal function. The RhoA/ROCK calcium-sensitizing pathway plays a role in genital smooth muscle contractile mechanism, but its regulation has never been elucidated. AIM: This study investigated the sex steroid regulation of the vaginal smooth muscle RhoA/ROCK pathway using a validated animal model. METHODS: Ovariectomized (OVX) Sprague-Dawley rats were treated with 17ß-estradiol (E2), testosterone (T), and T with letrozole (T + L) and compared with intact animals. Contractility studies were performed to test the effect of the ROCK inhibitor Y-27632 and the nitric oxide (NO) synthase inhibitor L-NAME. In vaginal tissues, ROCK1 immunolocalization was investigated; mRNA expression was analyzed by semiquantitative reverse transcriptase-polymerase chain reaction; and RhoA membrane translocation was evaluated by Western blot. Finally, rat vaginal smooth muscle cells (rvSMCs) were isolated from the distal vagina of intact and OVX animals, and quantification of the RhoA inhibitory protein RhoGDI was performed after stimulation with NO donor sodium nitroprusside, with or without administration of the soluble guanylate cyclase inhibitor ODQ or PRKG1 inhibitor KT5823. OUTCOMES: Androgens are critical in inhibiting the RhoA/ROCK pathway of the smooth muscle compartment in the distal vagina. RESULTS: ROCK1 was immunolocalized in the smooth muscle bundles and blood vessel wall of the vagina, with weak positivity detected in the epithelium. Y-27632 induced a dose-dependent relaxation of noradrenaline precontracted vaginal strips, decreased by OVX and restored by E2, while T and T + L decreased it below the OVX level. In Western blot analysis, when compared with control, OVX significantly induced RhoA activation, as revealed by its membrane translocation, with T reverting it at a level significantly lower than in controls. This effect was not exerted by E2. Abolishing NO formation via L-NAME increased Y-27632 responsiveness in the OVX + T group; L-NAME had partial effects in controls while not modulating Y-27632 responsiveness in the OVX and OVX + E2 groups. Finally, stimulation of rvSMCs from control animals with sodium nitroprusside significantly increased RhoGDI protein expression, counteracted by ODQ and partially by KT5823 incubation; no effect was observed in rvSMCs from OVX rats. CLINICAL IMPLICATIONS: Androgens, by inhibiting the RhoA/ROCK pathway, could positively contribute to vaginal smooth muscle relaxation, favoring sexual intercourse. STRENGTHS AND LIMITATIONS: This study describes the role of androgens in maintaining vaginal well-being. The absence of a sham-operated animal group and the use of the only intact animal as control represented a limitation to the study.

Neuroprotective Effects of Testosterone in the Hypothalamus of an Animal Model of Metabolic Syndrome.

Metabolic syndrome (MetS) is known to be associated to inflammation and alteration in the hypothalamus, a brain region implicated in the control of several physiological functions, including energy homeostasis and reproduction. Previous studies demonstrated the beneficial effects of testosterone treatment (TTh) in counteracting some MetS symptoms in both animal models and clinical studies. This study investigated the effect of TTh (30 mg/kg/week for 12 weeks) on the hypothalamus in a high-fat diet (HFD)-induced animal model of MetS, utilizing quantitative RT-PCR and immunohistochemical analyses. The animal model recapitulates the human MetS features, including low testosterone/gonadotropin plasma levels. TTh significantly improved MetS-induced hypertension, visceral adipose tissue accumulation, and glucose homeostasis derangements. Within hypothalamus, TTh significantly counteracted HFD-induced inflammation, as detected in terms of expression of inflammatory markers and microglial activation. Moreover, TTh remarkably reverted the HFD-associated alterations in the expression of important regulators of energy status and reproduction, such as the melanocortin and the GnRH-controlling network. Our results suggest that TTh may exert neuroprotective effects on the HFD-related hypothalamic alterations, with positive outcomes on the circuits implicated in the control of energy metabolism and reproductive tasks, thus supporting a possible role of TTh in the clinical management of MetS.

Physical activity counteracts metabolic syndrome-induced hypogonadotropic hypogonadism and erectile dysfunction in the rabbit.

Metabolic syndrome (MetS) clusters cardiovascular and metabolic risk factors along with hypogonadism and erectile dysfunction. Lifestyle modifications including physical exercise (PhyEx) are well-known treatments for this condition. In this study, we analyzed the effect of PhyEx on hypothalamic-pituitary-testis axis and erectile function by use of an animal MetS model, previously established in rabbits fed a high-fat diet (HFD). Rabbits fed a regular diet (RD) were used as controls. A subset of both groups was trained on a treadmill. HFD rabbits showed typical MetS features, including HG (reduced T and LH) and impairment of erectile function. PhyEx in HFD rabbits completely restored plasma T and LH and the penile alterations. At testicular and hypothalamic levels, an HFD-induced inflammatory status was accompanied by reduced T synthesis and gonadotropin-releasing hormone (GnRH) immunopositivity, respectively. In the testis, PhyEx normalized HFD-related macrophage infiltration and increased the expression of steroidogenic enzymes and T synthesis. In the hypothalamus, PhyEx normalized HFD-induced gene expression changes related to inflammation and glucose metabolism, restored GnRH expression, particularly doubling mRNA levels, and regulated expression of molecules related to GnRH release (kisspeptin, dynorphin). Concerning MetS components, PhyEx significantly reduced circulating cholesterol and visceral fat. In multivariate analyses, cholesterol levels resulted as the main factor associated with MetS-related alterations in penile, testicular, and hypothalamic districts. In conclusion, our results show that PhyEx may rescue erectile function, exert anti-inflammatory effects on hypothalamus and testis, and increase LH levels and T production, thus supporting a primary role for lifestyle modification to combat MetS-associated hypogonadism and erectile dysfunction.

Differential Effects of Testosterone and Estradiol on Clitoral Function: An Experimental Study in Rats.

INTRODUCTION: Female sexual response is a complex phenomenon in which psychological, neurologic, and vascular mechanisms and hormonal factors interact. During the arousal phase, they cooperate to increase genital blood flow, thus inducing engorgement of the clitoris and lubrication of the vagina. Regulation of vascular and non-vascular smooth muscle tone is the crucial event in the erectile process. Preclinical studies have suggested that nitric oxide (NO) is the main vasodilator neurotransmitter modulating, through the second messenger cyclic guanosine monophosphate (cGMP), clitoral flow vessels. AIM: To investigate the effects of sexual steroid hormones on pro-erectile and relaxant (mediated by NO and cGMP) and anti-erectile and contractile (mediated by ras homolog gene family member A [RhoA] and Rho-associated protein kinase [ROCK]) mechanisms in the clitoris using a validated animal model of female ovariectomized Sprague-Dawley rats. METHODS: Subgroups of ovariectomized rats were treated with 17ß-estradiol, progesterone, testosterone, or testosterone and letrozole for 6 weeks. The experimental groups were compared with a control group of intact rats. MAIN OUTCOME MEASURES: Sex steroids plasma levels were assessed and in vitro contractility studies were carried out in order to investigate the effect of ovariectomy and in vivo treatments on clitoris smooth muscle activity. Smooth muscle cells (SMCs) from rat clitoral biopsies were isolated and characterized. RhoA activity was determined in SMCs cell cultures. RNA from tissues and cells was analyzed by quantitative real-time RT-PCR. RESULTS: Using real-time polymerase chain reaction, testosterone treatment upregulated the expression of NO-mediated pathway genes (endothelial and neuronal NO synthase, guanylate cyclase soluble subunit-α3, guanylate cyclase soluble subunit-ß3, cGMP-dependent protein kinase 1, and phosphodiesterase type 5). Conversely, estrogen replacement upregulated the expression of calcium-sensitizing RhoA-ROCK pathway genes. In vitro contractility studies were performed on phenylephrine pre-contracted clitoris strips. Ovariectomy resulted in a decreased responsiveness to Y-27632, a ROCK inhibitor, which was fully restored by 17ß-estradiol supplementation. To further examine the effect of 17ß-estradiol on the RhoA-ROCK pathway, smooth muscle cells were isolated from rat clitoris and their migration capacity was evaluated. CONCLUSION: Collectively, these data demonstrate that testosterone improves the relaxation of vascular smooth muscle cells through the NO-cGMP pathway, and that testosterone and 17ß-estradiol are necessary to maintain a functional contractile and relaxant machinery in the clitoris. This new concept might provide support for the concomitant use of estrogen and testosterone during the treatment of sexual arousal disorders related to hormonal imbalance or insufficiency.

Estrogen mediates metabolic syndrome-induced erectile dysfunction: a study in the rabbit.

INTRODUCTION: Estrogen receptor (ER) α is critical in mediating the harmful effects of hyperestrogenism in fetal or neonatal life on the developing penis. In contrast, little is known on the impact of an excess of estrogens on penile function in adulthood. AIM: To investigate the effect of estrogens on metabolic syndrome (MetS)-associated erectile dysfunction (ED). METHODS: We employed a recently established animal model of high fat diet (HFD)-induced MetS. Subgroups of MetS rabbits were dosed with either testosterone (T) or tamoxifen. We evaluated penile responsiveness to acetylcholine (Ach) as well as the expression of genes related to penile smooth muscle relaxation and contractility. MAIN OUTCOME MEASURE: Associations between MetS-induced penile alterations and sex steroids were investigated in an animal model of HFD-induced MetS. To understand the role of either androgen deficiency or estrogen excess on ED, we treated subgroups of MetS rabbits with either T or tamoxifen, a classical ER antagonist. RESULTS: Feeding an HFD-induced MetS was associated to elevated estradiol (E2) and low T levels. E2, but not T, was independently and negatively associated with genes able to affect penile erection. Smooth muscle-related markers decreased as a function of E2 and were positively associated with all the variables investigated. Increasing concentrations of circulating E2 were negatively associated with Ach-induced relaxation. In HFD rabbits, in vivo T dosing significantly improved MetS and completely normalized circulating E2. Conversely, in vivo tamoxifen dosing reduced visceral adiposity and partially restored T level. Ach-induced relaxation was severely impaired by HFD and significantly restored, up to the control level, by both tamoxifen and T dosing. In rabbit smooth muscle cells cultures 17ß-E2 (1 nM) significantly reduced the expression of α-smooth muscle actin, transgelin, and phosphodiesterase type 5. The effects of 17ß-E2 were completely reverted by tamoxifen (100 nM). CONCLUSIONS: This study demonstrates, for the first time, that HFD-induced ED is more associated with a high E2, rather than to a low T, milieu. HFD-induced ED is partially restored by in vivo treatment not only with T but also with the nonsteroidal ER antagonist, tamoxifen.

Tadalafil effect on metabolic syndrome-associated bladder alterations: an experimental study in a rabbit model.

INTRODUCTION: Metabolic syndrome (MetS) and lower urinary tract symptoms (LUTS) are often associated. Bladder detrusor hyper-contractility-a major LUTS determinant-is characterized by increased Ras homolog gene family, member A/Rho-associated protein kinase (RhoA/ROCK) signaling, which is often upregulated in MetS. AIM: This study investigated the effects of tadalafil dosing on RhoA/ROCK signaling in bladder, in a rabbit model of high-fat diet (HFD)-induced MetS. METHODS: Adult male rabbits feeding a HFD for 12 weeks. A subset of HFD animals was treated with tadalafil (2 mg/kg/day, 1 week: the last of the 12 weeks) and compared with HFD and control (feeding a regular diet) rabbits. MAIN OUTCOME MEASURES: In vitro contractility studies to evaluate the relaxant effect of the selective ROCK inhibitor, Y-27632, in carbachol precontracted bladder strips. Evaluation of RhoA activation by its membrane translocation. Immunohistochemistry for ROCK expression has been performed to evaluate ROCK expression in bladder from the different experimental groups. mRNA expression of inflammation, pro-fibrotic markers by quantitative RT-PCR has been performed to evaluate the effect of tadalafil on MetS-induced inflammation and fibrosis within the bladder. The in vitro effect of tadalafil on RhoA/ROCK signaling in bladder smooth muscle cells was evaluated by using chemotaxis assay. RESULTS: Bladder strips from HFD rabbits showed hyper-responsiveness to Y-27632, indicating RhoA/ROCK overactivity in HFD bladder compared with matched controls. Accordingly, the fraction of activated (translocated to the membrane) RhoA as well as ROCK expression are increased in HFD bladder. Tadalafil dosing normalized HFD-induced bladder hypersensitivity to Y-27632, by reducing RhoA membrane translocation and ROCK overexpression. Tadalafil dosing reduced mRNA expression of inflammatory, pro-fibrotic, and hypoxia markers. A direct inhibitory effect of tadalafil on RhoA/ROCK signaling in bladder smooth muscle cell was demonstrated by using chemotaxis assay. Pre-treatment with tadalafil inhibited both basal and PDGF-induced migration of bladder smooth muscle cells. CONCLUSIONS: Tadalafil dosing reduced RhoA/ROCK signaling and smooth muscle overactivity in an animal model of MetS-associated bladder alterations. Our findings suggest a novel mechanism of action of tadalafil in alleviating LUTS in MetS patients.

Metformin in vitro and in vivo increases adenosine signaling in rabbit corpora cavernosa.

INTRODUCTION: In subjects with erectile dysfunction responding poorly to sildenafil, metformin was reported to improve erections. AIMS: The aim of this study is to investigate metformin's mechanism of action on erectile function, particularly focusing on adenosine (ADO) and nitric oxide (NO) signaling in an animal model of high-fat diet (HFD)-induced metabolic syndrome. METHODS: In vitro contractility studies of penile strips. Penile expression of genes related to ADO or NO signaling was also evaluated. MAIN OUTCOME MEASURE: In vitro contractility studies were used to investigate the effect of in vivo and ex vivo metformin administration on ADO- or acetylcholine (Ach)-induced relaxation of penile strips from HFD as compared with animals fed a regular diet (RD). RESULTS: Expression of ADO receptor type 3 (A3 R), ADO deaminase (ADA), AMP deaminase type 1 (AMPD1), and 2 (AMPD2) was decreased in HFD as compared with RD. Accordingly, in HFD the ADO relaxant effect was potentiated as compared with RD (P < 0.02). In vivo metformin treatment in both RD and HFD significantly increased the ADO relaxing effect (P < 0.0001 and P < 0.01, respectively, vs. relative untreated groups) although to a different extent. In fact, the half-maximal inhibitory concentration (IC50 )/IC50 ratio in RD increased fourfold vs. HFD (RD IC50 ratio = 13.75 ± 2.96; HFD IC50 ratio = 2.85 ± 0.52). In corpora cavernosa (CC) from HFD, in vivo metformin (i) normalized A3 R, ADA, and AMPD1; (ii) further decreased AMPD2; (iii) increased dimethylarginine dimethylamino-hydrolase; and (iv) partially restored impaired Ach-induced relaxation. Ex vivo metformin time and dose dependently increased the relaxant effect of ADO in RD. The potentiating effect of metformin on ADO-induced relaxation was significantly reduced by preincubation with NO synthase inhibitor N(ω) -Nitro-L-arginine methyl ester hydrochloride (L-NAME). Interestingly, in vivo testosterone supplementation in HFD rabbits (i) increased penile expression of endothelial NO synthase and AMPD2 and (ii) restored metformin's potentiating effect on ADO-induced relaxation up to RD level. CONCLUSION: Metformin in vivo and ex vivo increases ADO signaling in CC, most probably interfering with NO formation and ADO breakdown.

Mechanism of action of phosphodiesterase type 5 inhibition in metabolic syndrome-associated prostate alterations: an experimental study in the rabbit.

BACKGROUND: Phosphodiesterase type 5 (PDE5) inhibitors improve benign prostatic hyperplasia (BPH)-related lower urinary tract symptoms (LUTS), often associated with metabolic syndrome (MetS). This study investigated the effects of PDE5 inhibition in the prostate of rabbits fed a high fat diet (HFD) for 12 weeks. HFD-rabbits develop the most important features of human MetS (glucose intolerance, dyslipidemia, increased abdominal adiposity, and hypertension), along with hypogonadism and LUT abnormalities (prostate and bladder inflammation/tissue remodeling). METHODS: Gene expression was evaluated by quantitative RT-PCR. Prostate morphological changes and oxygenation were evaluated by immunohistochemistry. RESULTS: HFD prostates showed increased PDE5 expression, suggesting a peculiar sensitivity of prostate to the action of PDE5 inhibitors during MetS. Accordingly, prostate PDE5 mRNA was negatively associated to plasma testosterone/estradiol ratio, whose reduction characterizes MetS, and positively with the expression in prostate of several genes exploring pathogenetic processes for BPH/LUTS, such as inflammation, leukocyte infiltration, and fibrosis/myofibroblast activation. Most of these genes was up-regulated by HFD, and significantly reduced by PDE5 inhibition, through either chronic (12 weeks) or, at a lower extent, acute (1-week) tadalafil dosing. Tadalafil was also able to reduce blood pressure and visceral fat in HFD rabbits, without changing any other MetS parameter. Interestingly, 1-week tadalafil administration to HFD rabbits, significantly blunted prostate inflammation (increased CD45 immunopositivity), fibrosis (reduced muscle/fiber ratio) and hypo-oxygenation, thus suggesting a potential curative effect of PDE5 inhibition on MetS-related prostate alterations. CONCLUSIONS: Our data provide the experimental evidences to support the multiple potentiality of PDE5 inhibitors as a useful therapeutic tool in LUTS.

PDE5 inhibitors blunt inflammation in human BPH: a potential mechanism of action for PDE5 inhibitors in LUTS.

BACKGROUND: Metabolic syndrome (MetS) and benign prostate hyperplasia (BPH)/low urinary tract symptoms (LUTS) are often comorbid. Chronic inflammation is one of the putative links between these diseases. Phosphodiesterase type 5 inhibitors (PDE5i) are recognized as an effective treatment of BPH-related LUTS. One proposed mechanism of action of PDE5 is the inhibition of intraprostatic inflammation. In this study we investigate whether PDE5i could blunt inflammation in the human prostate. METHODS: Evaluation of the effect of tadalafil and vardenafil on secretion of interleukin 8 (IL-8, a surrogate marker of prostate inflammation) by human myofibroblast prostatic cells (hBPH) exposed to different inflammatory stimuli. We preliminary evaluate histological features of prostatic inflammatory infiltrates in BPH patients enrolled in a randomized, double bind, placebo controlled study aimed at investigating the efficacy of vardenafil (10 mg/day, for 12 weeks) on BPH/LUTS. RESULTS: In vitro treatment with tadalafil or vardenafil on hBPH reduced IL-8 secretion induced by either TNFα or metabolic factors, including oxidized low-density lipoprotein, oxLDL, to the same extent as a PDE5-insensitive PKG agonist Sp-8-Br-PET-cGMP. These effects were reverted by the PKG inhibitor KT5823, suggesting a cGMP/PKG-dependency. Treatment with tadalafil or vardenafil significantly suppressed oxLDL receptor (LOX-1) expression. Histological evaluation of anti-CD45 staining (CD45 score) in prostatectomy specimens of BPH patients showed a positive association with MetS severity. Reduced HDL-cholesterol and elevated triglycerides were the only MetS factors significantly associated with CD45 score. In the MetS cohort there was a significant lower CD45 score in the vardenafil-arm versus the placebo-one.

Testosterone/estradiol ratio regulates NO-induced bladder relaxation and responsiveness to PDE5 inhibitors.

INTRODUCTION: The efficacy of phosphodiesterase type 5 inhibitors (PDE5i) in treating lower urinary tract symptoms is supported by the extremely high expression and activity of PDE5 in male bladder. Although bladder function regulation is similar among genders, no data are available on PDE5 expression and activity in female bladder. AIM: To investigate sex differences in PDE5 expression and biological activity in female bladder, as opposed to the male counterpart. MAIN OUTCOME MEASURE: Gene and protein expression and enzymatic activity of PDE5. METHODS: We studied gene and protein expression, and enzymatic activity of PDE5 in bladder of male and female rats. A subgroup of female rats was ovariectomized and alternatively replaced with estradiol (E2), progesterone, and testosterone (T) alone or in combination with letrozole to completely abrogate T-induced E formation. As a readout of PDE5 activity, we studied vardenafil efficacy in potentiating sodium nitroprusside (SNP)-induced relaxation in bladder of the different experimental groups. RESULTS: SNP was three-log unit less potent in relaxing the male bladder than the female one. On the contrary, the PDE5-resistant cyclic guanosine monophosphate (cGMP) analog (Bromo-ß-phenyl-1, N(2) -ethenoguanosine-3', 5'-cyclic monophosphorothioate, Sp-isomer [SP-8-Br-PET-cGMPS]) was equipotent in relaxing male and female bladder. Vardenafil was more effective in potentiating SNP-induced bladder relaxation in male than in female. Accordingly, the cGMP-hydrolyzing activity of PDE5 was higher in male vs. female homogenates. In ovariectomized female rats, with or without sex-steroid replacement, vardenafil activity in potentiating SNP-induced bladder relaxation was associated with an increased T/E2 ratio. In particular, masculinization of ovariectomized rats--by the administration of T + letrozole--dramatically increased vardenafil capacity to potentiate SNP-induced relaxation. CONCLUSION: In this study, we demonstrated that PDE5 activity is more pronounced in male as compared with female bladder and that T/E ratio positively regulates responsiveness to PDE5i, thus suggesting that male bladder is a more suitable target for PDE5i than the female counterpart.

Consequences of Anabolic-Androgenic Steroid Abuse in Males; Sexual and Reproductive Perspective.

The real epidemiology and the possible consequences of anabolic-androgenic steroids (AAS) use still represent a very tricky task due to the difficulties in the quantification and detection of these drugs. Chronic use of AAS, frequently combined with other illicit substances, can induce tremendous negative effects on the reproductive system, but it is also associated with an increased overall and cardiovascular mortality risk. In the present review we summarize and discuss the available evidence regarding the negative impact of AAS on the male reproductive system, providing practical suggestions to manage these problems. For this purpose a meta-analysis evaluating the effects of AAS abusers vs. controls on several hormonal, reproductive and metabolic parameters was performed. In addition, in order to overcome possible limitations related to the combined use of different AAS preparations, we also retrospectively re-analyzed data on animal models treated with supraphysiological dosage of testosterone (T), performed in our laboratory. Available data clearly indicated that AAS negatively affect endogenous T production. In addition, increased T and estradiol circulating levels were also observed according to the type of preparations used. The latter leads to an impairment of sperm production and to the development of side effects such as acne, hair loss and gynecomastia. Furthermore, a worse metabolic profile, characterized by reduced high density lipoprotein and increased low density lipoprotein cholesterol levels along with an increased risk of hypertension has been also detected. Finally sexual dysfunctions, often observed upon doping, represent one the most probable unfavorable effects of AAS abuse.

Spermatogenic and sperm quality differences in an experimental model of metabolic syndrome and hypogonadal hypogonadism.

The synergistic effect of the co-morbidities that comprise metabolic syndrome (MetS) is increasingly being recognised as an important contributor in the pathology of a broad spectrum of seemingly disparate conditions. However, in terms of male reproductive function, beyond erectile dysfunction, little is known about the influence of this cohort (collectively or separately) on spermatogenesis and sperm quality. The aims of this study were to assess the reproductive tract of a MetS animal model for detrimental changes, to determine whether a group of compounds (advanced glycation end products and their receptor) known to cause cell dysfunction and DNA damage was present and assess whether hypogonadotropic hypogonadism was the main contributing factor for the changes seen. Animals fed a high-fat diet were found to have significantly increased cholesterol, triglycerides, blood glucose, mean arterial pressure and visceral fat levels. Although serum testosterone was decreased, no changes were seen in either testicular or epididymal histology. Immunolocalisation of N(ε)-carboxymethyl-lysine and the receptor for advanced glycation end products was found in the testes, epididymides and sperm of the two treated groups of animals; however, ELISA did not show any difference in protein levels. Similarly, assessment of sperm nuclear DNA (nDNA) fragmentation by acridine orange test did not find significant differences in nDNA integrity. We conclude that the minimal effect on spermatogenesis and sperm quality seen in our model is probably due to the moderate increase of blood glucose rather than the hypogonadism.

Phosphodiesterase type 5 expression in human and rat lower urinary tract tissues and the effect of tadalafil on prostate gland oxygenation in spontaneously hypertensive rats.

INTRODUCTION: In humans, prostate phosphodiesterase type 5 inhibitors (PDE5) expression was prominently localized in the endothelial and smooth muscle cells of the vascular bed, suggesting a possible action of PDE5 inhibitors (PDE5i) on prostate blood flow. AIM: To investigate PDE5 expression in human and rat lower urinary tract (LUT) tissues, including vasculature, and determine the effects of PDE5 inhibition with tadalafil on prostatic blood perfusion. MAIN OUTCOME MEASURES: Human vesicular-deferential arteries (which originate from the inferior vesical artery, the main arterial source of blood supply to the bladder and prostate) were analyzed for PDE5 expression and activity. The effects of tadalafil on prostate oxygenation were studied in spontaneously hypertensive rats (SHR), characterized by ischemia/hypoxia of the genitourinary tract. METHODS: PDE5 expression was evaluated by quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. SHR were treated with tadalafil (2 mg/kg/day) for 1, 7, or 28 days and compared with untreated SHR and the unaffected counterpart Wistar-Kyoto (WKY) rats. Prostate oxygenation was detected by Hypoxyprobe-1 and hypoxia markers (hypoxia-inducible factor-1α[HIF-1α] and endothelin-1 type B [ETB]) immunostaining. RESULTS: Human vesicular-deferential artery expressed high levels of PDE5, similar to corpora cavernosa, immunolocalized in the endothelial and smooth muscle layer. In these arteries, tadalafil inhibited cyclic guanosine monophosphate breakdown (half maximal inhibitory concentration (IC(50) ) in the low nanomolar range, as in corpora cavernosa) and increased the relaxant response to sodium nitroprusside. SHR prostate resulted markedly hypoxic (hypoxyprobe immunopositivity) and positive for HIF-1α and ETB, while tadalafil treatment restored oxygenation to WKY level at each time point. The mRNA expression of the HIF-1α target gene, BCL2/adenovirus E1B 19 kDa interacting protein 3, was significantly increased in SHR prostate and partially restored to WKY level by tadalafil. CONCLUSION: Human vesicular-deferential artery is characterized by a high expression and activity of PDE5, which was inhibited by tadalafil in vitro. In SHR, tadalafil increases prostate tissue oxygenation, thus suggesting a possible mechanism through which PDE5i exert beneficial effects on LUT symptoms.

Farnesoid X receptor activation improves erectile function in animal models of metabolic syndrome and diabetes.

INTRODUCTION: The farnesoid X receptor (FXR) is critically involved in the regulation of the hepato-biliary system. Recent data suggest a role for FXR in modulating other metabolic pathways and vascular function. AIM: To investigate whether long-term administration of the selective FXR agonist INT-747 ameliorates erectile function, we tested it in two animal models of metabolic derangements: a rabbit model of high-fat diet (HFD)-induced metabolic syndrome (MetS) and a rat model of streptozotocin (STZ)-induced type 1 diabetes. METHODS: HFD rabbit or STZ rats with or without chronic INT-747 dosing (10 mg/kg/day for 12 weeks). INT-747 addition to rabbit penile smooth muscle cells (rpSMCs). MAIN OUTCOME MEASURE: Effects of INT-747 on metabolic features and erectile function in animal models and clarification of mechanism of action in isolated cells. RESULTS: INT-747 dosing normalized visceral adiposity and glucose intolerance in HFD rabbits. INT-747 increased penile FXR expression and partially restored endothelial nitric oxide synthase and dimethylarginine dimethylaminohydrolase 1 expression as well as impaired nitric oxide (NO)-dependent relaxation (improved responsiveness to acetylcholine and electrical field stimulation). INT-747 was also effective in regulating NO downstream events, as shown by increased sodium nitroprusside-induced relaxation. Because phosphodiesterase type 5 and protein kinase G (PKG) were unaltered by INT-747, we analyzed the calcium-sensitizing RhoA/ROCK pathway. HFD increased, and INT-747 normalized, RhoA membrane translocation/activation. RhoA/ROCK signaling inhibition by INT-747 was confirmed in rpSMCs by confocal microscopy, MYPT1-phosphorylation, cytoskeleton remodeling, cell migration, and smooth muscle-related genes expression. In STZ rats, FXR penile expression was not altered but was significantly upregulated by INT-747 dosing. In this model, INT-747 improved penile erection induced by electrical stimulation of cavernous nerve and hypersensitivity to intracavernous injection of a ROCK-inhibitor, Y-27632, without improving hyperglycemia. CONCLUSION: In HFD rabbits, INT-747 dosing improved glucose sensitivity and MetS-associated erectile dysfunction, via upregulation of NO transmission and inhibition of RhoA/ROCK pathway. In STZ rats, INT-747 restored in vivo penile erection and sensitivity to ROCK inhibition, independently of effects on glycemia.

Cardiovascular Risks of Androgen Deprivation Therapy for Prostate Cancer.

Androgen deprivation therapy (ADT) is the gold standard treatment in patients with locally advanced or metastatic prostate cancer (PC). Emerging evidence has documented a tight association between ADT and body composition, along with metabolic profile impairment. These alterations might underpin the observed ADT-related increase in cardiovascular (CV) and thromboembolic (venous thromboembolism, VTE) mortality and morbidity. However, the specific mechanisms underlying these associations have not yet been completely elucidated. In the present review we summarize and discussed the available evidence linking ADT to increased cardio-metabolic risk, using both preclinical and clinical data. When possible, meta-analytic studies were preferred. Preclinical evidence, using a rabbit model of gonadotrophin-releasing hormone analogue-induced hypogonadism, indicates that the induced condition is associated with a dramatic increase in visceral adiposity and with an impairment of acetylcholine induced vascular relaxation, along with an increased propensity towards fatty liver. This suggests a direct role of ADT in inducing a worsened metabolic profile. In contrast, available clinical data are not sufficient to clarify a direct pathogeniclink between reduced testosterone (T) and altered metabolism. In fact, although T deprivation is associated with an altered metabolism, it is possible that the association between ADT and CV or VTE risk could simply be the result of a selection bias, related to the poor health status of patients with advanced PC. Despite the aforementioned considerations, all patients who are candidatesfor ADT should be screened for CV risk factors at baseline and monitored during the therapy. Life-style modifications and physical exercise are strongly encouraged.

Insight on the Intracrinology of Menopause: Androgen Production within the Human Vagina.

In this study, we investigated steroidogenic gene mRNA expression in human vaginas and verified the ability of human vagina smooth muscle cells (hvSMCs) to synthesize androgens from upstream precursor dehydroepiandrosterone (DHEA). As a readout for androgen receptor (AR) activation, we evaluated the mRNA expression of various androgen-dependent markers. hvSMCs were isolated from vagina tissues of women undergoing surgery for benign gynecological diseases. In these cells, we evaluated mRNA expression of several steroidogenic enzymes and sex steroid receptors using real time reverse transcription-polymerase chain reaction. Androgen production was quantified with liquid chromatography tandem-mass spectrometry (LC-MS/MS). In vaginal tissues, AR mRNA was significantly less expressed than estrogen receptor α, whereas in hvSMCs, its mRNA expression was higher than progestin and both estrogen receptors. In hvSMCs and in vaginal tissue, when compared to ovaries, the mRNA expression of proandrogenic steroidogenic enzymes (HSD3ß1/ß2, HSD17ß3/ß5), along with 5α-reductase isoforms and sulfotransferase, resulted as being more abundant. In addition, enzymes involved in androgen inactivation were less expressed than in the ovaries. The LC-MS/MS analysis revealed that, in hvSMCs, short-term DHEA supplementation increased Δ4-androstenedione levels in spent medium, while increasing testosterone and DHT secretion after longer incubation. Finally, androgenic signaling activation was evaluated through AR-dependent marker mRNA expression, after DHEA and T stimulation. This study confirmed that the human vagina is an androgen-target organ with the ability to synthesize androgens, thus providing support for the use of androgens for local symptoms of genitourinary syndrome in menopause.

The soluble guanylyl cyclase inhibitor NS-2028 reduces vascular endothelial growth factor-induced angiogenesis and permeability.

Nitric oxide (NO) is known to promote vascular endothelial growth factor (VEGF)-stimulated permeability and angiogenesis. However, effector molecules that operate downstream of NO in this pathway remain poorly characterized. Herein, we determined the effect of soluble guanylyl cyclase (sGC) inhibition on VEGF responses in vitro and in vivo. Treatment of endothelial cells (EC) with VEGF stimulated eNOS phosphorylation and cGMP accumulation; pretreatment with the sGC inhibitor 4H-8-bromo-1,2,4-oxadiazolo(3,4-d)benz(b)(1,4)oxazin-1-one (NS-2028) blunted cGMP levels without affecting VEGF-receptor phosphorylation. Incubation of cells with NS-2028 blocked the mitogenic effects of VEGF. In addition, cells in which sGC was inhibited exhibited no migration and sprouting in response to VEGF. To study the mechanisms through which NS-2028 inhibits EC migration, we determined the effects of alterations in cGMP levels on p38 MAPK. Initially, we observed that inhibition of sGC attenuated VEGF-stimulated activation of p38. In contrast, the addition of 8-Br-cGMP to EC stimulated p38 phosphorylation. The addition of cGMP elevating agents (BAY 41-2272, DETA NO and YC-1) enhanced EC migration. To test whether sGC also mediated the angiogenic effects of VEGF in vivo, we used the rabbit cornea assay. Animals receiving NS-2028 orally displayed a reduced angiogenic response to VEGF. As increased vascular permeability occurs prior to new blood vessel formation, we determined the effect of NS-2028 in vascular leakage. Using a modified Miles assay, we observed that NS-2028 attenuated VEGF-induced permeability. Overall, we provide evidence that sGC mediates the angiogenic and permeability-promoting activities of VEGF, indicating the significance of sGC as a downstream effector of VEGF-triggered responses.

Vardenafil can improve continence recovery after bilateral nerve sparing prostatectomy: results of a randomized, double blind, placebo-controlled pilot study.

INTRODUCTION: Phosphodiesterase type 5 inhibitors (PDE5-I) have acquired an established role in the treatment of post-prostatectomy erectile dysfunction (ED). Several trials in men with ED and lower urinary tract symptoms associated with benign prostatic hyperplasia suggest that PDE5-I could improve both erectile function and urinary symptoms. AIM: To assess the role of vardenafil in continence recovery after bilateral nerve sparing radical prostatectomy (BNS-RP). METHODS: Thirty-nine patients with prostate cancer were recruited. After BNS-RP, patients were double-blinded assigned to three arms: a) vardenafil on demand; b) vardenafil nightly; and c) placebo. MAIN OUTCOMES MEASURES: Urinary function (UF) and urinary bother (UB) of University of California-Los Angeles Prostate Cancer Index questionnaire were assessed preoperatively and at 1, 3, 6, 9, 10, and 12 months. Twelve-month outcomes were compared to 1 month with a t-test. The differences in UF and UB (at 3, 6, 9, 10, and 12 months) between the three treatment arms were calculated by an analysis of variance. With ALLFIT we estimated half-maximal recovery times (ER50) and maximal recovery (R(max)) in three groups. RESULTS: The improvement of UF and UB between 1 and 12 months was significant in all arms except for placebo (UF: P = 0.125; UB: P = 0.089). Nightly resulted in greater UF at 3, 6, and 9 months and greater UB at 6 months compared with placebo (P = 0.042, P = 0.044 and P = 0.039); after nightly administration, patients presented higher UB than after on-demand use, 3 and 6 months postoperatively (P = 0.036 and P = 0.017). ALLFIT demonstrated a similar ER50 in all groups (2.6 months for both UF and UB) and indicated that nightly administration induced significant improvements in R(max) compared with placebo (both <0.0001). CONCLUSIONS: Vardenafil can improve continence recovery after BNS-RP compared with placebo. The daily use of vardenafil seems to provide better continence rate, although it does not seem to influence the timing needed to achieve full continence.

Acute vardenafil administration improves bladder oxygenation in spontaneously hypertensive rats.

INTRODUCTION: In human bladder, phosphodiesterase type 5 (PDE5) is present not only in the muscular wall but also in the vascular beds, suggesting a role for PDE5 inhibitors in favoring bladder blood flow and tissue oxygenation. AIM: To investigate whether acute administration of vardenafil could affect bladder oxygenation in spontaneously hypertensive rats (SHR), an animal model of naturally occurring overactive bladder. MAIN OUTCOME MEASURES: The effect of vardenafil on hypoxia-induced alterations was studied in vivo in SHR by acute dosing (10 mg/kg, 90 minutes before sacrifice) and in vitro in human bladder smooth muscle cells (hBCs). METHODS: Bladder oxygenation was detected using the hypoxyprobe immunostaining. The expression of some hypoxia markers (vascular endothelial growth factor [VEGF] and endothelin-1 type B [ETB] receptor) was also evaluated by immunohistochemistry and Western blot. Gene expression in hBC was quantified by real-time reverse transcription-polymerase chain reaction. RESULTS: Rat bladder PDE5 immunopositivity was detected in the muscular wall and in the endothelial and smooth muscle cells of blood vessels. In SHR bladder, a significant increase of hypoxic cells, VEGF, and ETB expression was observed when compared with their normotensive counterpart Wistar Kyoto rats (WKY). Vardenafil treatment dramatically decreased hypoxyprobe staining, as well as VEGF and ETB expression in SHR bladder up to WKY level. Accordingly, in SHR bladder, vardenafil administration significantly blunted relaxation induced by the selective ETB agonist IRL-1620. In hBCs, experimental hypoxia significantly induced gene expression of hypoxia markers (carbonic anhydrase IX and VEGF), which was not changed by simultaneous treatment with vardenafil. Conversely, the hypoxia-related induction of smooth muscle-specific genes (alphaSMA, SM22alpha, and desmin) was significantly reduced by vardenafil. CONCLUSIONS: SHR showed bladder hypoxia which was significantly reduced by acute vardenafil treatment. Thus, besides relaxing muscular wall, PDE5 inhibition may positively affect urinary vesicle blood perfusion.

Sex steroid receptors in male human bladder: expression and biological function.

INTRODUCTION: In male, lower urinary tract symptoms (LUTS) have been associated, beside benign prostatic hyperplasia, to some unexpected comorbidities (hypogonadism, obesity, metabolic syndrome), which are essentially characterized by an unbalance between circulating androgens/estrogens. Within the bladder, LUTS are linked to RhoA/Rho-kinase (ROCK) pathway overactivity. AIM: To investigate the effects of changing sex steroids on bladder smooth muscle. METHODS: ER α, ER ß, GPR30/GPER1 and aromatase mRNA expression was analyzed in male genitourinary tract tissues, and cells isolated from bladder, prostate, and urethra. Estrogen and G1 effect on RhoA/ROCK signaling output like cell migration, gene expression, and cytoskeletal remodeling, and [Ca(2+) ](i) was also studied in hB cells. Contractile studies on bladder strips from castrated male rats supplemented with estradiol and testosterone was also performed. MAIN OUTCOME MEASURES: The effects of classical (ER α, ER ß) and nonclassical (GPR30/GPER1) estrogen receptor ligands (17 ß-estradiol and G1, respectively) and androgens on RhoA/ROCK-.mediated cell functions were studied in hB cells. Contractility studies were also performed in bladder strips from castrated male rats supplemented with testosterone or estradiol. RESULTS: Aromatase and sex steroid receptors, including GPR30, were expressed in human bladder and mediates several biological functions. Both 17 ß-estradiol and G1 activated calcium transients and induced RhoA/ROCK signaling (cell migration, cytoskeleton remodeling and smooth muscle gene expression). RhoA/ROCK inhibitors blunted these effects. Estrogen-, but not androgen-supplementation to castrated rats increased sensitivity to the ROCK inhibitor, Y-27632 in isolated bladder strips. In hB cells, testosterone elicited effects similar to estrogen, which were abrogated by blocking its aromatization through letrozole. CONCLUSION: Our data indicate for the first time that estrogen-more than androgen-receptors up-regulate RhoA/ROCK signaling. Since an altered estrogen/androgen ratio characterizes conditions, such as aging, obesity and metabolic syndrome, often associated to LUTS, we speculate that a relative hyperestrogenism may induce bladder overactivity through the up-regulation of RhoA/ROCK pathway.