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Erectile dysfunction is highly prevalent in type II diabetes mellitus. Low intensity extracorporeal shock wave therapy improves erectile function in patients with erectile dysfunction of vasculogenic origin, including diabetes. However, its mode of action remains unknown. We investigated the effects of low intensity extracorporeal shock wave therapy compared to or combined with sildenafil on erectile dysfunction in a type II diabetes mellitus model. Our purpose was to test our hypothesis of a mode of action targeting the cavernous nitric oxide/cyclic guanosine monophosphate pathway.GK rats, a validated model of type II diabetes mellitus, and age matched Wistar rats were treated with low intensity extracorporeal shock wave therapy twice weekly for 3 weeks. Treatment was repeated after a 3-week no-treatment interval. The penis was stretched and dipped in a specifically designed water-filled cage. Shock waves were delivered by a calibrated probe yielding a controlled energy flux density (0.09 mJ/mm(2)). The probe was attached to an electrohydraulic unit with a focused shock wave source, allowing for accurate extrapolation to humans. Following a 4-week washout period erectile function was assessed as well as endothelium dependent and independent, and nitrergic relaxations of the corpus cavernosum of GK rats.Low intensity extracorporeal shock wave therapy significantly improved erectile function in GK rats to the same extent as sildenafil. Treatment effects were potentiated when combined with sildenafil. Shock wave effects were not associated with improved cavernous endothelium dependent or independent, or nitrergic reactivity.Low intensity extracorporeal shock wave therapy improved erectile function in GK rats. Unexpectedly, this was not mediated by a nitric oxide/cyclic guanosine monophosphate dependent mechanism. Sildenafil increased shock wave efficacy. This preclinical paradigm to deliver low intensity extracorporeal shock wave therapy to the rat penis should help further exploration of the mode of action of this therapy on erectile tissue.

Introduction Following the results of the EMPA-REG Outcome trial, we hypothesized that empagliflozin, a highly potent and specific sodium/glucose cotransporteur 2 inhibitor, could improve type 2 diabetes mellitus (T2DM)-associated erectile dysfunction (ED), a highly prevalent complication of T2DM, very often coexisting with cardiovascular complications and considered as a prognostic factor of cardiovascular disease in men with diabetes. Aim To investigate the effects of chronic treatment with empagliflozin on ED in a T2DM rat model in the presence or absence of sildenafil. Methods Male Goto-Kakizaki (GK), a model of T2DM, and age-matched Wistar rats received placebo or empagliflozin treatment at 25.3 ± 0.9 mg/kg/d for 4 weeks. Then, the in vivo effect of empagliflozin on erectile function was assessed by electrical stimulation of the cavernous nerve at different frequencies under anesthesia in the presence or absence of acute intravenous injection of sildenafil. Endothelium-dependent, -independent, and nitrergic relaxations of cavernosal strips from the rats were studied. Main Outcome Measures Body weight, food consumption, metabolic parameters, plasma inflammation biomarkers, and in vivo erectile responses elicited by electrical stimulation of the cavernous nerve in empagliflozin-treated and untreated GK rats and control Wistar rats were assessed and followed by concentration or frequency response curves to endothelium-dependent, -independent, and nitrergic relaxations of cavernosal strips from these rats. Results Chronic empagliflozin followed by acute sildenafil significantly improved erectile responses in adult GK rats (n = 12–15/group). Ratios of intracavernous pressure and area under the curve/mean arterial pressure during the electrical stimulation were significantly increased in empagliflozin-treated vs untreated GK rats. Nitrergic relaxations of cavernosal strips from GK rats were significantly increased with empagliflozin compared with placebo. Moreover, the effect of sildenafil on erectile function was not altered by empagliflozin treatment. Clinical Implications Empagliflozin may benefit T2DM patient with ED. Strengths & Limitations The mechanism(s) by which empagliflozin shows favorable effect on erectile function in GK rats needs to be further elucidated. Conclusion Empagliflozin shows favorable effect on erectile function in diabetic GK rats mediated by an improvement of nitrergic relaxation of erectile tissue. Whether this favorable effect on ED in the experimental context of T2DM is due to better glycemic control or to another effect of empagliflozin deserves further investigation.

Flibanserin, a 5-HT1A agonist and 5-HT2A antagonist, is developed for the treatment of hypoactive sexual desire disorder in women, and its efficacy has been evidenced in several clinical studies. Flibanserin prosexual effects have been also evidenced in preclinical animal models. However, the mechanism of action of flibanserin remains not fully understood. The aim of the present study was to examine brain neuronal activation in female rats treated with flibanserin, using single immunocytochemical labeling of Fos protein, a marker of neuronal activation, and co-localization of Fos and catecholaminergic marker. Six groups of female rats received either acute or chronic administrations of vehicle, flibanserin 15 mg/kg or flibanserin 45 mg/kg. The brains were collected and processed for immunocytochemical labeling. Acute flibanserin increased levels of Fos immunoreactivity in the nucleus accumbens, arcuate hypothalamic nucleus, locus coeruleus, lateral paragigantocellular nucleus, and nucleus of the solitary tract. Chronic 22-day treatment with flibanserin increased Fos expression in the medial preoptic area and arcuate nucleus of the hypothalamus, ventral tegmental area, locus coeruleus, and lateral paragigantocellular nucleus. Both acute and chronic flibanserin increased the density of activated catecholaminergic neurons in the ventral tegmental area but not in the locus coeruleus. Altogether, our results showed that flibanserin, at the dose known to enhance female sexual motivation, preferentially activated the brain regions belonging to the mesolimbic dopaminergic pathway and hypothalamic structures involved in the integration of sexual cues related to sexual motivation.

Background Lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH) and erectile dysfunction (ED) are highly prevalent in aging men and are strongly linked. Alpha 1 -blockers such as alfuzosin are effective monotherapies for LUTS. Phosphodiesterase type 5 (PDE5) inhibitors such as tadalafil are the first-line treatment for ED. Both drugs act by two different mechanisms of action on common urogenital target organs and, thus, may have additive effects. Objectives We evaluated in vitro the effects of alfuzosin, tadalafil, and the combination of both on human detrusor and prostatic smooth muscle. Design, setting, and participants Prostatic and bladder tissue were obtained from patients ( n =20 and n =17, respectively) undergoing cystoprostatectomy for bladder cancer. Measurements In organ baths, isolated prostatic strips and isolated bladder strips were incubated with vehicle, tadalafil (10 −6 M and 10 −5 M), alfuzosin (3×10 −8 M or 10 −6 M and 10 −5 M) or a combination. Concentration-response curves (CRCs) to norepinephrine were generated on prostatic strips and detrusor strips precontracted with carbachol. Strips were also submitted to electrical field stimulation (EFS). Results and limitations When alfuzosin and tadalafil were combined, the maximal relaxation to norepinephrine on carbachol-precontracted detrusor strips was significantly increased compared with tadalafil alone, and EFS-induced detrusor contractions were better inhibited compared with each compound alone. Tadalafil significantly inhibited norepinephrine-induced prostatic strip contractions by reducing the maximal effect, whereas alfuzosin shifted the CRC of norepinephrine to the right. Combining both tadalafil and alfuzosin resulted in a greater relaxant effect. Likewise, the combination was more effective at reducing EFS-induced contractions compared with each compound alone. Conclusions The combination of alfuzosin and tadalafil exerts an additive effect of inhibiting adrenergic smooth muscle tone of prostatic tissue and EFS-induced detrusor contractions and conversely, of enhancing adrenergic relaxation of detrusor precontracted with carbachol. These experiments provide experimental support for the clinical investigation of the combination of α1-blockers and PDE5 inhibitors in the treatment of LUTS.

BACKGROUND Insulin resistance constitutes a risk factor for endothelial dysfunction and subsequent cardiovascular diseases including hypertension. Daily treatment with phosphodiesterase type 5 (PDE5) inhibitors has beneficial effects on endothelial function in men with increased cardiovascular risk. Endothelium-dependent vasomotor function is ultimately linked to blood pressure (BP) regulation. We postulated that sildenafil would ameliorate BP and biological markers of endothelial function in fructose-fed rats (FFRs). METHODS Wistar rats were fed a standard chow or a 60% fructose-enriched diet containing 12% fat for 8 weeks (FFR). From week 6 through 8, sildenafil (twice a day subcutaneously, 20 mg/kg) was administered followed by a 1-week washout period. At the end of the washout period, BP was recorded using radiotelemetry following cumulative infusion of norepinephrine (from 50 to 400 ng/kg/min). RESULTS FFR displayed both an impaired glucose tolerance and elevated triglyceridemia. The latter was corrected by sildenafil treatment. Resting BP was similar in all rats, whereas pressor responses were significantly enhanced in FFR (maximal increase in mean BP to norepinephrine: 25.6 +/- 3.8 vs. 40.8 +/- 4.0 mm Hg, P < 0.05) and normalized by sildenafil treatment (24.9 +/- 5.3 mm Hg, not significant vs. control). Urinary levels of 8-isoprostanes and thromboxane B(2) were increased in FFR and corrected by sildenafil treatment. CONCLUSION Thus, chronic treatment with sildenafil normalized BP regulation in an experimental model of insulin resistance and hypertriglyceridemia while restoring normal excretion of urinary biological markers of oxidative stress and cyclooxygenase-derived vasoconstrictors. The modulation of ROS and cyclooxygenase-derived vasoconstrictors generation by a chronic treatment with sildenafil may represent an added benefit beyond PDE5 inhibition.

Erectile dysfunction (ED) is another manifestation of vascular disease. We evaluated the natural history of ED in the spontaneously hypertensive rat (SHR) and the respective participation of associated pathophysiological modifications, i.e., endothelial dysfunction and tissue remodeling. SHR and their normotensive counterparts [Wistar-Kyoto rats (WKY)] of 6, 12, and 24 wk of age ( n = 12) were used to evaluate erectile function, erectile and aortic tissue reactivity, and remodeling. Erectile responses in SHR are reduced at all ages ( P < 0.001). In both aortic and erectile tissues of SHR and WKY, relaxations to ACh are altered progressively with age, although more markedly in SHR. They are decreased at 12 wk of age in erectile tissue of SHR compared with WKY (maximal relaxation: −19.2 ± 2.8% vs. −28.3 ± 3.9%, P < 0.001) but only at 24 wk of age in aortas (−47.9 ± 6.4% vs. −90.5 ± 2.9%, P < 0.001). Relaxations to sodium nitroprusside are unaltered in aortic rings of both strains but enhanced in erectile tissue of SHR at 12 wk of age. Major modifications in the distribution of collagen I, III, and V in SHR occur in both types of tissue and are detectable sooner in erectile tissue compared with aortic tissue. The onset of ED is detectable before the onset of hypertension in the SHR. Structural and functional alterations, while similar, occur earlier in erectile compared with vascular tissue. If confirmed in humans, ED could be an early warning sign for hypertension, and common therapeutic strategies targeting both ED and hypertension could be investigated.

The relaxant effect of an aryloxypropanolamine β3-adrenoceptor agonist on carbachol pre-contracted human detrusor muscle strips was evaluated and compared with literature results from reference compounds of similar mode of action, including mirabegron. A significant relaxation was observed for rac-4-{2-hydroxy-3-[1-(5-phenylthieno[2,3-d]pyrimidin-4-yl)piperidin-4-ylamino]propoxy}-2-(hydroxymethyl)phenol which was similar to that exerted by mirabegron. In order to allow for a thorough discussion of results in comparison to reference compounds, their affinity, selectivity and efficacy as hβ3-AR agonists have been evaluated and discussed thoroughly. A ranking of hβ3-AR agonists by relative efficacy resulted in the closest analogy to the order of relaxation potential, with only the relaxant effect of mirabegron not reflecting its excellent relative efficacy as such.

OBJECTIVE To characterize the spontaneous contractile activity (SCA) developed by detrusor from patients with neurogenic detrusor overactivity (NDO) because the alteration of detrusor properties plays a critical role in the pathogenesis of detrusor overactivity, as well as to evaluate the role of KATP and KCa channels on this SCA because these channels regulate detrusor SCA in many species, including humans without overactive bladder (OAB). PATIENTS AND METHODS Human bladder samples were obtained from 44 patients undergoing cystectomy for bladder cancer with no known OAB symptoms and from 38 patients suffering from urodynamically diagnosed NDO. Detrusor strips with or without urothelium/suburothelium were mounted isometrically in organ baths filled with Krebs-HEPES (37 °C; 95% O2/5% CO2). Strips were incubated with 10 µm pinacidil (KATP opener) followed by 10 µm glibenclamide (KATP blocker). In another set of experiments, strips were incubated with 30 µm NS-1619 (BKCa opener) followed by 100 nm iberiotoxin (BKCa blocker) or with 100 nm apamin (SKCa blocker). RESULTS SCA occurred more frequently with larger amplitude and area under the curve in detrusor strips from NDO patients compared to control patients. The presence of urothelium/suburothelium did not significantly modify SCA in either patient population. Pinacidil markedly inhibited SCA of detrusor strips from control and NDO patients. This effect was reversed by glibenclamide. By contrast, NS-1619 followed by iberiotoxin did not elicit any significant changes in SCA from NDO patients, contrary to control patients. CONCLUSIONS KATP and SKCa channels regulate SCA of NDO patients’ detrusor strips. By contrast, BKCa channels are not involved in the regulation of detrusor SCA in NDO patients, whereas they regulate SCA in control patients. These results should be considered in the development of K+ channels openers for the treatment of NDO. Moreover, SCA observed in vitro should be regarded as an in vitro modelling of human NDO.

Objectifs Des etudes cliniques rapportent l’utilisation d’ondes de choc de faible intensite (Li-ESWT) appliquees sur la verge pour traiter la dysfonction erectile (DE). Le mecanisme d’action de cette therapeutique innovante reste inconnu. Nous avons evalue l’efficacite des Li-ESWT dans le contexte experimental de la DE associee au diabete utilisant le rat diabetique Goto-Kakizaki (GK) et son controle normoglycemique Wistar pour preciser le mecanisme d’action des Li-ESWT. Methodes Certains rats GK ( n = 24) ont recu 2 series de traitements bi-hebdomadaires par Li-ESWT (Omnispec ED1000, Medispec), separees de 3 semaines sans traitement. Ce protocole de traitement par Li-ESWT reproduisait exactement le protocole humain. Parmi ces rats GK, certains ont egalement recu 0,3 mg/kg iv de sildenafil au moment de l’evaluation de la fonction erectile, 4 semaines apres la derniere seance par Li-ESWT, en mesurant la pression intracaverneuse lors de stimulations electriques du nerf caverneux. La reactivite en bain d’organes isoles des corps caverneux (CC) issus des memes rats a ete egalement mesuree afin d’explorer le role eventuel de la voie NO/cGMP. Resultats La fonction erectile des rats diabetiques GK est significativement diminuee en comparaison des rats controles Wistar et associee a une diminution des relaxations endothelium-dependantes, -independantes et nitrergiques des corps caverneux. Les Li-ESWT ont significativement ameliore la fonction erectile des rats diabetiques GK. De plus, le sildenafil a augmente significativement l’effet pro-erectile du traitement par Li-ESWT. Cependant, la relaxation des CC n’a pas ete amelioree par Li-ESWT, qu’elle soit endothelium-dependante, -independante ou nitrergique. Conclusion Li-ESWT ameliore la fonction erectile des rats diabetiques de type II GK. Le sildenafil associe aux Li-ESWT ameliore encore ces reponses. L’effet therapeutique des Li-ESWT est independant de la voie du NO/cGMP. D’autres etudes sont necessaires pour comprendre le mecanisme d’action des Li-ESWT.

Flow (shear stress)-mediated dilation (FMD) plays a key role in the local control of vascular diameter and blood flow supply. Although vasodilator treatments improve FMD in diverse models of hypertension, FMD may also change in situations where systemic blood pressure is not affected. In pathological situations such as ischemia, local blood flow and vascular density are increased by vasodilators not affecting systemic blood pressure. As the mechanisms involved remain obscure, we studied FMD in resistance arteries from mice treated chronically (1 month) with hydralazine (200 mg/L in drinking water). Blood flow in mesenteric arteries of mice treated with hydralazine was significantly increased (130 +/- 15 to 169 +/- 27 microl/min, n = 10/group), whereas mean arterial blood pressure was not affected (79 +/- 5 vs 82 +/- 3 mm Hg in controls). Mesenteric resistance arteries (90 microm internal diameter, 75 mm Hg) were isolated and mounted in vitro in an arteriograph. Pressure (myogenic tone)-, phenylephrine-, and KCl-induced contractions, as well as acetylcholine- and sodium nitroprusside-induced dilations, were unaffected by hydralazine. Flow-mediated dilation in arteries from hydralazine-treated mice was significantly increased, especially for low flow values (up to sevenfold). L-NAME-sensitive and indomethacin-sensitive FMD were both increased by hydralazine. Passive arterial diameter increased and arterial wall thickness decreased after chronic hydralazine. This is the first functional evidence that flow (shear stress)-mediated dilation in resistance arteries is improved by a chronic treatment with a nonselective vasodilator. This arteriolar adaptation to a chronic increase in blood flow might be of importance in the pathophysiology of ischemic diseases.

We have previously shown that angiotensin II (Ang II) and pressure increase extracellular signal-regulated kinase (ERK) 1/2 activity synergistically in intact, pressurized resistance arteries in vitro. However, the mechanisms by which pressure and Ang II activate ERK1/2 in intact resistance arteries remain to be determined. The purpose of the present study was to investigate the involvement of Rho-kinase and the actin filament network in Ang II- and pressure-induced ERK1/2 activation, as well as in the contractile response induced by Ang II. Mesenteric resistance arteries (200 to 300 microm) were isolated, mounted in an arteriograph, and stimulated by pressure, Ang II, or both. Activation of ERK1/2 was then measured by an in-gel assay. In mesenteric resistance arteries maintained at 70 mm Hg, Ang II (0.1 micromol/L) induced contraction (29+/-1.4% of phenylephrine, 10 micromol/L-induced contraction) and significantly increased ERK1/2 activity. Selective inhibition of Rho-kinase by Y-27632 (10 micromol/L) and selective disruption of the actin filament network by cytochalasin B (10 micromol/L) both decreased the Ang II-induced contraction by 78+/-1.2% and 87+/-1.9%, respectively, and significantly diminished ERK1/2 activity. In the absence of Ang II, increasing intraluminal pressure from 0 to 70 or 120 mm Hg increased ERK1/2 activity. ERK1/2 activity at 120 mm Hg was similar to that observed at 70 mm Hg in the presence of Ang II. Pressure-induced ERK1/2 activation was markedly attenuated by cytochalasin B but not by Y-27632. These results indicate that whereas pressure-induced ERK1/2 activation requires an intact actin filament network, but not Rho-kinase, the activation of ERK1/2 and the contraction induced by Ang II require both Rho-kinase and an intact actin filament network in isolated, intact mesenteric resistance arteries.

Human bladder samples were obtained from 15 different patients with no known OAB undergoing cystectomy for bladder cancer. Detrusor strips without urothelium were mounted isometrically at a resting tension of 500 mg in a 5 ml organ bath filled with Krebs-HEPES buffer maintained at 37°C and bubbled w ith 95%O2-5%CO2. The strips were connected to force transducers for isometric tension recordings (Pioden Controls Ltd, UK). Following amplification, the tension changes were computerized via MacLabTM/8 using ChartTM 5 software (AD Instruments Ltd).

reduce lower urinary tract symptoms (LUTS) in men. The mechanism of action is not fully understood. Since LUTS comprise urgency, frequency and nocturia which are arising mainly from the bladder, we investigated the effects of PDE5 inhibitors on the dog bladder. We determined the effects of PDE5 inhibitors in vitro, on dog bladder strips and in vivo on micturition frequency and volume per voiding in conscious dogs. METHODS: Bladder strips from male Beagle dogs were pre

INTRODUCTION ● Lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) are highly prevalent in aging men and are strongly linked, independently of age and cardiovascular comorbidities1. ● Alpha1-adrenergic blockers such as alfuzosin are considered the most effective monotherapy for LUTS associated with benign prostatic hyperplasia (BPH)2. ● Phophodiesterase 5 (PDE5) inhibitors are a first line treatment for erectile dysfunction (ED)3. ● Recent clinical trials have shown that PDE5 inhibitors (sildenafil, tadalafil, vardenafil) could improve not only ED but also obstructive and irritative LUTS associated with BPH4-6. Interestingly, this beneficial effect on LUTS is not associated with an increased peak flow rate suggesting an extraprostatic mode of action. ● A pilot clinical study also indicates that daily administration of alfuzosin (10mg) in combination with sildenafil (25 mg) for 12 weeks may be more effective than monotherapy on LUTS associated with BPH and ED7. ● Tadalafil is currently the only one long-acting PDE5 inhibitor and the maximum prescribed dose (20 mg) shows no clinically relevant hemodynamic interaction with alfuzosin 10mg once daily8.

Background —Dystrophin has a key role in striated muscle mechanotransduction of physical forces. Although cytoskeletal elements play a major role in the mechanotransduction of pressure and flow in vascular cells, the role of dystrophin in vascular function has not yet been investigated. Thus, we studied endothelial and muscular responses of arteries isolated from mice lacking dystrophin (mdx mice). Methods and Results —Carotid and mesenteric resistance arteries 120 μm in diameter were isolated and mounted in vitro in an arteriograph to control intraluminal pressure and flow. Blood pressure was not affected by the absence of dystrophin. Pressure-induced (myogenic), phenylephrine-induced, and KCl-induced forms of tone were unchanged. Flow (shear stress)–induced dilation in arteries isolated from mdx mice was decreased by 50% to 60%, whereas dilation to acetylcholine or sodium nitroprusside was unaffected. NG-nitro-L-arginine methyl ester–sensitive flow dilation was also decreased in arteries from mdx mice. Thus, the absence of dystrophin was associated with a defect in signal transduction of shear stress. Dystrophin was present in vascular endothelial and smooth muscle cells, as shown by immunolocalization, and localized at the level of the plasma membrane, as seen by confocal microscopy of perfused isolated arteries. Conclusions —This is the first functional study of arteries lacking the gene for dystrophin. Vascular reactivity was normal, with the exception of flow-induced dilation. Thus, dystrophin could play a specific role in shear-stress mechanotransduction in arterial endothelial cells. Organ damage in such diseases as Duchenne dystrophy might be aggravated by such a defective arterial response to flow.