Erectile Response Research Articles

STIM/Orai Inhibition as a Strategy for Alleviating Diabetic Erectile Dysfunction Through Modulation of Rat and Human Penile Tissue Contractility and in vivo Potentiation of Erectile Responses

Stromal interaction molecule (STIM)/Orai calcium entry system appears to have a role in erectile dysfunction (ED) pathophysiology but its specific contribution to diabetic ED was not elucidated. To evaluate STIM/Orai inhibition on functional alterations associated with diabetic ED in rat and human penile tissues and on in vivo erectile responses in diabetic rats. Rat corpus cavernosum (RCC) strips from nondiabetic (No DM) and streptozotocin-induced diabetic (DM) rats and human penile resistance arteries (HPRA) and corpus cavernosum (HCC) from ED patients undergoing penile prosthesis insertion were functionally evaluated in organ chambers and wire myographs. Erectile function in vivo in rats was assessed by intracavernosal pressure (ICP) responses to cavernous nerve electrical stimulation (CNES). Expression of STIM/Orai elements in HCC was determined by immunofluorescence and immunoblot. Functional responses in RCC, HCC and HPRA and STIM/Orai protein expression in HCC. In vivo erectile responses to CNES. Inhibition of Orai channels with YM-58483 (20 µM) significantly reduced adrenergic contractions in RCC but more effectively in DM. Thromboxane-induced and neurogenic contractions were reduced by STIM/Orai inhibition while defective endothelial, neurogenic and PDE5 inhibitor-induced relaxations were enhanced by YM-58483 (10 µM) in RCC from DM rats. In vivo, YM-58483 caused erections and attenuated diabetes-related impairment of erectile responses. YM-58483 potentiated the effects of PDE5 inhibition. In human tissues, STIM/Orai inhibition depressed adrenergic and thromboxane-induced contractions in ED patients more effectively in those with type 2 diabetes. Diabetes was associated with increased expression of Orai1 and Orai3 in ED patients. Targeting STIM/Orai to alleviate diabetes-related functional alterations of penile vascular tissue could improve erectile function and potentiate therapeutic effects of PDE5 inhibitors in diabetic ED. Improving effects of STIM/Orai inhibition on diabetes-related functional impairment was evidenced in vitro and in vivo in an animal model and validated in human tissues from ED patients. Functional findings were complemented with expression results. Main limitation was low numbers of human experiments due to limited human tissue availability. STIM/Orai inhibition alleviated alterations of functional responses in vitro and improved erectile responses in vivo in diabetic rats, potentiating the effects of PDE5 inhibition. STIM/Orai inhibition was validated as a target to modulate functional alterations of human penile vascular tissue in diabetic ED where Orai1 and Orai3 channels were upregulated. STIM/Orai inhibition could be a potential therapeutic strategy to overcome poor response to conventional ED therapy in diabetic patients. Sevilleja-Ortiz A, El Assar M, García-Gómez B, et al. STIM/Orai Inhibition as a Strategy for Alleviating Diabetic Erectile Dysfunction Through Modulation of Rat and Human Penile Tissue Contractility and in vivo Potentiation of Erectile Responses. J Sex Med 2022;19:1733-1749.

THE BENEFICIAL EFFECT OF INTRACAVERNOSAL INJECTION OF SILDENAFIL ON ERECTILE DYSFUNCTION IN DUTASTERIDE TREATED RATS

Objective: Benign prostatic hyperplasia (BPH) and erectile dysfunction (ED) are the most common illnesses in aged male patients. 5α-reductase inhibitors (5-ARIs) are suggested for the treatment of BPH. Furthermore, the association of 5ARIs with ED has been indicated. This study aimed to investigate the effect of intracavernosal injection of sildenafil on ED in 5ARI treated rats.Material and Method: Sprague-Dawley rats (n=30) were divided into three groups: Control; 10-week dutasteride treatment (0.5 mg/rat/day); and 6-week durasteride treatment followed by a 4-week washout period. In vivo erectile responses were assessed before and after intracavernosal injection of sildenafil (0.3mg/kg/rat). The relaxant and contractile responses of isolated corpus cavernosum were evaluated in in vitro organ bath.Result and Discussion: Prostate weight decreased after 10-week dutasteride treatment. In vivo erectile responses, endothelial and nitrergic relaxation responses were decreased in dutasteride groups. The washout period moderately normalized erectile responses. The intracavernosal injection of sildenafil increased erectile function in treatment groups. Contractile responses were augmented in 10-week dutasteride treated rats. The cessation of the treatment did not alter erectile function as well as endothelial relaxation and nitrergic relaxation. Also, intracavernosal sildenafil caused an improvement in 5ARI treatment-induced ED.

Sodium butyrate ameliorates erectile dysfunction through fibrosis in a rat model of partial bladder outlet obstruction.

In different animal models, a histone deacetylase (HDAC) inhibitor, sodium butyrate (NaBu) reduced inflammation, oxidative stress and fibrosis which were involved in the pathogenesis of erectile dysfunction (ED), but whether NaBu could improve ED in an experimental animal model of benign prostate hyperplasia (BPH) was not known. To investigate the preventive effect of NaBu on ED in a partial bladder outlet obstruction (PBOO) rat model. PBOO was induced by partial urethral obstruction. NaBu (20mg/kg/day) was administered orally to rats for 6 weeks after creation of PBOO. In vivo erectile responses, in vitro relaxation and contraction responses in cavernosal tissue were measured. Real-time polymerase chain reaction (RT-PCR) and Western blot were performed to determine the gene and protein expression. Inflammation, fibrosis, and localization of proteins were evaluated using histological techniques. HDAC activity and tumor necrosis factor (TNF)-α levels were measured in penile tissues. NaBu improved decreased intracavernosal pressure/mean arterial pressure, nitrergic and endothelium-dependent relaxation responses, and contractile responses to phenylephrine and electrical field stimulation in the PBOO group without affecting increased bladder weight. Increased endothelial nitric oxide synthase (eNOS), transforming growth factor (TGF)-β1, and nuclear factor kappa B (NF-κB) gene levels in PBOO group were ameliorated by NaBu treatment. The administration of NaBu to PBOO rats significantly increased neuronal NOS (nNOS) and decreased TGF-β1 protein expression. The nuclear/cytosolic ratio of NF-κB demonstrated a decrease in PBOO and all treatment groups compared to control. A significant increase in the nuclear-to-cytoplasmic ratio of nuclear factor erythroid 2-related factor 2 (Nrf2) after PBOO was reduced by the treatment. Both eNOS and inducible NOS (iNOS) protein expression, together with TNF-α levels did not differ in the penile tissue of all groups. In histological analysis, increased TGF-β1 protein expression and fibrosis, as well as decreased nNOS protein in PBOO, were reversed by the treatment. NaBu did not normalize moderate inflammation in obstructed rats. An increase in the HDAC activity in PBOO was significantly suppressed by NaBu. Inhibition of the HDAC activity by NaBu in penile tissue could ameliorate fibrosis-associated changes induced by PBOO. NaBu promotes recovery of erectile function, and also significantly prevents penile fibrosis and normalizes TGF-β1 and nNOS protein expression in a rat model of PBOO. The HDAC pathway may present a promising target to prevent ED in patients with BPH.

Do pornography use and masturbation play a role in erectile dysfunction and relationship satisfaction in men?

Both masturbation frequency and pornography use during masturbation have been hypothesized to interfere with sexual response during partnered sex as well as overall relationship satisfaction. However, results from prior studies have been inconsistent and frequently based on case studies, clinical reports, and simple binary analyses. The current study investigated the relationships among masturbation frequency, pornography use, and erectile functioning and dysfunction in 3586 men (mean age = 40.8 yrs, SE = 0.22) within a multivariate context that assessed sexual dysfunctions using standardized instruments and that included other covariates known to affect erectile functioning. Results indicated that frequency of pornography use was unrelated to either erectile functioning or erectile dysfunction (ED) severity in samples that included ED men with and without various sexual comorbidities or in a subset of men 30 years or younger (p = 0.28-0.79). Masturbation frequency was also only weakly and inconsistently related to erectile functioning or ED severity in the multivariate analyses (p = 0.11-0.39). In contrast, variables long known to affect erectile response emerged as the most consistent and salient predictors of erectile functioning and/or ED severity, including age (p < 0.001), having anxiety/depression (p < 0.001 except for a subset of men ≤ 30 years), having a chronic medical condition known to affect erectile functioning (p < 0.001 except for a subset of men ≤ 30 years), low sexual interest (p < 0.001), and low relationship satisfaction (p ≤ 0.04). Regarding sexual and relationship satisfaction, poorer erectile functioning (p < 0.001), lower sexual interest (p < 0.001), anxiety/depression (p < 0.001), and higher frequency of masturbation (p < 0.001) were associated with lower sexual and lower overall relationship satisfaction. In contrast, frequency of pornography use did not predict either sexual or relationship satisfaction (p ≥ 0.748). Findings of this study reiterate the relevance of long-known risk factors for understanding diminished erectile functioning while concomitantly indicating that masturbation frequency and pornography use show weak or no association with erectile functioning, ED severity, and relationship satisfaction. At the same time, although verification is needed, we do not dismiss the idea that heavy reliance on pornography use coupled with a high frequency of masturbation may represent a risk factor for diminished sexual performance during partnered sex and/or relationship satisfaction in subsets of particularly vulnerable men (e.g., younger, less experienced).

Paeonol ameliorates diabetic erectile dysfunction by inhibiting HMGB1/RAGE/NF-kB pathway.

The management of diabetes mellitus-induced erectile dysfunction (DMED) is progressively becoming tricky due to the surge in the number of patients and the poor efficiency of phosphodiesterase type 5 inhibitors in DMED. Paeonol (Pae), as a traditional Chinese medicine, has been more and more widely used in the treatment of diabetic complications. However, whether Pae could be a potential therapeutic drug of DMED needs to be further evaluated. To investigate the pharmacological effect and possible mechanism of Pae in the treatment of DMED. Intraperitoneal streptozotocin injection and an apomorphine test were used to construct the model of DMED. Seventeen DMED rats were divided into two groups: DMED group (n=8) and DMED+Pae group (Pae; 100mg/kg/d; oral administration; n=9). In addition, there were still 10 normal age-matched male rats as control group. Four weeks later, the cavernous nerve electric stimulation was carried out to measure the erectile response. Moreover, the corpus cavernosum smooth muscle cells (CCSMCs) were primarily isolated and exposed to high glucose (HG) stimulation, Pae treatment and glycyrrhizin (GL; the selective inhibitor of HMGB1). After an incubation for 1week, the CCSMCs were harvested for detection. The impairment of erectile function was observed in DMED rats compared with control samples, accompanied by the upregulation of HMGB1/RAGE/NF-κB Pathway. The lower nitric oxide and cGMP level and the higher level of inflammation, fibrosis, and apoptosis were also observed in DMED rats. It showed contrast that Pae treatment could improve the erectile function, as well as histologic alteration and related molecular changes. In addition, Pae could downregulate the HMGB1/RAGE/NF-κB pathway to regulate the apoptosis and inflammation levels of CCSMCs in high-glucose conditions, which is similar to the results of GL treatment. Pae alleviated ED in DMED rats, likely by inhibiting HMGB1/RAGE/NF-κB Pathway, inflammatory, apoptosis, and fibrotic activity, and moderating endothelial dysfunction. Our study provide evidence for a potential new therapy for DMED.

MP38-03 COMBINATION TREATMENT WITH A JNK INHIBITOR AND HEPATOCYTE GROWTH FACTOR FOR RESTORATION OF ERECTILE FUNCTION IN A RAT MODEL OF CAVERNOSAL NERVE INJURY: COMPARISON WITH A JNK INHIBITOR ALONE OR HEPATOCYTE GROWTH FACTOR ALONE

You have accessJournal of UrologyCME1 May 2022MP38-03 COMBINATION TREATMENT WITH A JNK INHIBITOR AND HEPATOCYTE GROWTH FACTOR FOR RESTORATION OF ERECTILE FUNCTION IN A RAT MODEL OF CAVERNOSAL NERVE INJURY: COMPARISON WITH A JNK INHIBITOR ALONE OR HEPATOCYTE GROWTH FACTOR ALONE Junghoon Lee, Sangjun Yoo, Min Soo Choo, Hwancheol Son, Hyeon Jeong, Soo Woong Kim, and Min Chul Cho Junghoon LeeJunghoon Lee More articles by this author , Sangjun YooSangjun Yoo More articles by this author , Min Soo ChooMin Soo Choo More articles by this author , Hwancheol SonHwancheol Son More articles by this author , Hyeon JeongHyeon Jeong More articles by this author , Soo Woong KimSoo Woong Kim More articles by this author , and Min Chul ChoMin Chul Cho More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002592.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The structural derangements of the corpus cavernosum are known to be potential causes of intractable impotence or to limit efficacy of PDE5 inhibitors by inducing cavernosal venoocclusive dysfunction, a key pathophysiology of postprostatectomy erectile dysfunction. The aim of this study was to determine if combined administration of a JNK inhibitor and HGF (hepatocyte growth factor) would restore erectile function through both antiapoptotic and regenerative effects in a rat model of erectile dysfunction induced by cavernous nerve crush injury (CNCI), and to compare it with administration of a JNK inhibitor alone or HGF alone. METHODS: We randomized 70 rats into five experimental groups for two weeks from the day of CNCI: a sham surgery group (S), a CNCI (I) group, a group treated with once-daily intraperitoneal administration of 10.0 mg/kg of JNK inhibitor (J), a twice-weekly intracavernosal administration of 4.2 μg HGF group (H), and a combined treatment with 10.0 mg/kg JNK inhibitor and 4.2 μg HGF group (J+H). We investigated erectile responses to electrostimulation, histological staining, caspase-3 activity assay, and immunoblotting at two weeks following surgery. RESULTS: The three treatment groups showed improvements in the erectile responses (ICP/MAP or AUC/MAP ratio) after stimulation at all voltages as compared to the I group. The erectile responses in the J+H group were greater than those in the J or H group. The erectile responses in the J+H group were not generally different from those in the S-group. Regarding the cavernosal apoptosis, the caspase-3 activity and c-Jun phosphorylation in the J and J+H groups were improved as compared to the I group, whereas the caspase-3 activity in the H group partially improved. Regarding the endothelial status and smooth muscle (SM) content, the protein expression of PECAM-1, eNOS phosphorylation, and α-SM actin content in the J+H group were normalized, although those in the J or H group were partially restored. Phosphorylation of cMet was normalized in the H and J+H groups. CONCLUSIONS: Our data indicates that combination therapy with a JNK inhibitor and HGF can generally normalize erectile function through antiapoptosis and the preservation of cavernosal endothelium or SM in a rat CN injury model. The combined treatment with these two kinds of agents also appears to be superior to the respective agent alone in terms of the therapeutic effects. Source of Funding: This research was supported by the National Research Foundation of Korea, grant 2018R1D1A1A09083833, and by the JEIL Pharmaceutical Co., LTD, grant 01-2018-33 © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e619 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Junghoon Lee More articles by this author Sangjun Yoo More articles by this author Min Soo Choo More articles by this author Hwancheol Son More articles by this author Hyeon Jeong More articles by this author Soo Woong Kim More articles by this author Min Chul Cho More articles by this author Expand All Advertisement PDF DownloadLoading ...

Treatment with levothyroxine and testosterone ameliorated erectile dysfunction in a rat model of propylthiouracil-induced hypothyroidism

ABSTRACT Introduction The endocrine disease frequently interrupts sexual function, and sexual dysfunction may signal serious endocrine disease. Recent studies have claimed an association with hypothyroidism, low testosterone (T) levels and erectile dysfunction (ED), but causality is unclear. There is no study on the experimental model of hypothyroidism that was induced in rats by administration of propylthiouracil (PTU). Objective The purpose of this study was to investigate the deleterious effects of PTU-induced hypothyroidism on ED and T levels. In addition, Levothyroxine is known worldwide as the most common and least effective drug for controlling hypothyroidism. Methods Adult Sprague-Dawley rats (n = 35) were divided into five groups; control, PTU-induced hypothyroidism, PTU+ Levothyroxine, PTU+ Sustanon (a mixture of 4 types of T: propionate, phenylpropionate, isocaproate, decanoate) and PTU+ Levothyroxine + Sustanon. PTU was given in drinking water (0.05%) for 6 weeks. 4 weeks after the beginning of PTU treatment, Levothyroxine (20 mg/kg/day, oral) and Sustanon (10 mg/kg, I.M., once/week) were given for 2 weeks. Serum levels of total T, triiodothyronine (T3) and thyroxine (T4) were determined. The ratio of intracavernosal pressure (ICP) to mean arterial pressure (MAP) and total ICP were measured by cavernous nerve stimulation. The relaxant and contractile responses were evaluated on in vitro preparations of corpus cavernosum (CC) strips. The expression and localization of neuronal (nNOS), endothelial NOS (eNOS) and phosphodiesterase type 5 (PDE5​) were determined using Western blotting and immunohistochemistry. The relative area of smooth muscle to collagen was measured using Masson trichrome staining. Results The rat model of hypothyroidism showed a significant decline in serum levels of total T, T3 and T4. Levothyroxine increased T3 and T4 levels while Sustanon normalized only total T levels. In addition, combined treatment of Levothyroxine and Sustanon enhanced all hormone levels. Rats with hypothyroidism displayed the lowest ICP/MAP ratio and total ICP for 7.5 V (P &amp;lt; .001 vs controls). Combined treatment returned reduced ICP/MAP and total ICP responses, while partial amelioration was observed after Levothyroxine and Sustanon treatment alone. In vitro endothelium-dependent acetylcholine-caused relaxation at 1 nM (P &amp;lt; .001 vs controls), electrical field stimulation-induced relaxant response at 20 Hz (P &amp;lt; .001 vs controls) and sildenafil-induced relaxation at 10 µM (P &amp;lt; .05 vs controls) were decreased in the CC strips from hypothyroid rats. The treatment with Levothyroxine and Sustanon increased the reduction in relaxation responses. Decreased in the expressions of eNOS and nNOS and increased in the expressions of PDE5 in the hypothyroid group were restored by Levothyroxine and Sustanon. Mono-treatment partially enhanced reduced smooth muscle mass while combined therapy completely recovered. Conclusions These results show that hypothyroidism adversely affects T levels and erectile responses via decreasing neurogenic and endothelium-dependent relaxation responses which were reversed by the combination therapy with Levothyroxine and Sustanon. Even though the associated alterations in T levels, ED and its reversibility indicate an exact role of thyroid hormones in the erection physiology. Disclosure Work supported by industry: no.

Factors associated with the decrease in orgasm intensity in patients who underwent to radical prostatectomy

ABSTRACT Introduction Orgasmic disorders after radical prostatectomy (RP) surgery have received increasing focus on medical literature, especially the most frequent disorders, to name but a few, climacturia and dysorgasmia. However, changes in orgasm intensity have been reported to non-negligible rates and should be better studied. Objective Our study aims at describing the prevalence and predictors of this neglected symptom. Methods We performed a retrospective analysis of a prospective maintained database of men after RP with complaints of sexual dysfunction. Patients observed a sexual medicine group of our hospital went throught a supervised visit which included the investigation of orgasmic disorders. Other factors such as erectile dysfunction, hypogonadism symptoms, seric level of testosterone and prolactin, and demographics were also recorded. Finally, these variables were correlated with the decrease in orgasm intensity, seeking to assess the existence of predictive factors for this disorder. Results Data from 57 patients were available considering the average age of 67 years old (65,4-68,6 CI, 95%). The decrease in orgasm intensity was reported by 14 patients (24,5%), while climacturia was related to 38 patients (68%) and dysorgasmia to one patient (1,75%). Among patients who experienced decreased orgasm intensity, the average time between the surgery and the search for our service was 27,5 months (15,6-39,4 CI, 95%). After using a logistic regression model adjusted to several variables which include age, time from the last surgery, testosterone and prolactin levels, hypogonadic symptoms, presence of climacturia or dysorgasmia, erectile dysfunction and response to IPDE-5, use of adjuvant radiotherapy or hormonotherapy, it was realized that age was the only factor associated with the lowering of orgasm intensity. The median age was significantly lower in those patients who reported a reduction in orgasm intensity, respectively 62 [59-67] x 68 [64-73] (p &amp;lt;0.01). Conclusions Orgasmic disorders after radical prostatectomy surgery have a high incidence and are often neglected. These symptoms have a direct impact on the quality of life and should be actively investigated. Our study showed that age appears to be a relevant factor associated with this condition. Disclosure Work supported by industry: no.

Recovery of erectile dysfunction after administration of hydrogen sulfide donor sodium hydrogen sulfide and transplantation of adipose-derived stem cells in rats with bilateral cavernous nerve injury

ABSTRACT Introduction Radical prostatectomy causes nerve injury-related erectile dysfunction (ED), which results in a poor response to phosphodiesterase 5 inhibitors. Hydrogen sulfide (H2S), an endogenous gasotransmitter, is produced by cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST) and participates in erectile physiology. Adipose-derived stem cells (ADSCs) represent a promising cell source for cell replacement therapy in several degenerative diseases because of its self-renewal properties and multi-differentiation potential with low immunogenicity. Objective The current study was to evaluate the effects of H2S donor, sodium hydrogen sulfide (NaHS), and transplantation of ADSCs per se and their combination treatment on bilateral cavernous nerve injury (BCNI)-induced erectile dysfunction (ED). Methods A total of 35 Sprague-Dawley rats were divided into 5 groups, including sham-operated (Sham), BCNI (4-wk), BCNI treated with NaHS (5.6 mg/kg/day, i.p.), BCNI treated with ADSCs (1x106 cells by intracavernosal injection) and BCNI treated with NaHS and ADSCs groups. Rats in the ADSCs treatment groups were subjected to intracavernosal injection after BCNI. Erectile function was evaluated by the ratio of intracavernous pressure (ICP)/mean arterial pressure (MAP) and total ICP. The relaxant and contractile responses of corpus cavernosum (CC) were measured from in vitro studies. Protein expression and localization of nitric oxide synthases (NOS) and H2S synthesis enzymes were analyzed by Western blotting and immunohistochemistry. The smooth muscle/collagen ratio was determined using Masson trichrome staining. Results Rats with BCNI displayed significantly reduced ICP/MAP and total ICP (p&amp;lt;0.001 vs controls) when were partially restored by NaHS and ADSCs treatments alone. Interestingly, combined treatment completely enhanced decreased in vivo erectile responses (p&amp;lt;0.001 vs the NC group). Relaxation responses to acetylcholine and electrical field stimulation (EFS) as well as contractile responses to phenylephrine and EFS in the CN group were less than in controls (p&amp;lt; 0.05), which was normalized after all treatments groups. The combined treatment modulated changes of protein expressions and reduced ratio of smooth muscle to collagen in rats with BCNI. Conclusions The current data indicated that the combination treatment with NaHS and ADSCs is more successful than monotherapies in reversing BCNI-induced ED. H2S and cell-based therapy most probably may have a synergistic effect on erectile function via controlling molecular regulation and morphological penile alterations, which supports combined treatment for expanding clinical outcomes radical prostatectomy-induced ED. Disclosure Work supported by industry: no.

Grapefruit peel extract mitigates paroxetine-induced erectile dysfunction in rats through stimulation of erectile response, antioxidant status, and inhibition of key enzymes related with impaired penile erection.

Despite the antidepressant potency of paroxetine, its side effect of erectile dysfunction is burdensome. Grapefruit peels (GFPs) are underutilized cultivar wastes with wide range of therapeutic potentials which have been attributed to their antioxidant behavior and phenolic contents' abilities to effectively inhibit enzymatic activities and manage endothelial dysfunction in cardiovascular disorders. This study aims to investigate the erectogenic potentials of GFP extract in a rat model of paroxetine-induced ED. Experimental rats were sectioned into five groups: [1: control; 2: paroxetine (10mg/kg); 3: paroxetine + sildenafil (5mg/kg); 4: paroxetine + GFP (50 mg/kg); 5: paroxetine + GFP (100 mg/kg)] and treated for 28 days. Sexual behavior of rats was assessed and effect of GFP on ecto-5' nucleotidases, phosphodiesterase-5, and adenosine deaminase (ADA) activities was determined in rats' penile tissues. The levels of malondialdehyde, nitric oxide (NO) as well as superoxide dismutase (SOD) and catalase activities were also determined. HPLC-DAD analysis showed the presence of naringin, rutin, caffeic acid, quercitrin, quercetin, and kaempferol glycoside. Oral administration of paroxetine reduced erectile response as revealed by their low intromission and mounting numbers as well as high intromission and mounting latencies. Paroxetine caused a significant elevation of ADA and phosphodiesterase-5 activities and malondialdehyde levels with drastic reduction in levels of NO, SOD, and catalase activities in rats' penile tissues. However, GFP extract reversed PDE-5, ADA, and antioxidant activities to normal levels, raised the concentration of NO. These results suggest the erectogenic effects and protective potentials of GFP extract against paroxetine-induced erectile dysfunction. PRACTICAL APPLICATION: Grapefruit peels are an environmental menace in many countries and this study showed that the peels can be used in the prevention / management of erectile dysfunction. The therapeutic potentials of the peels are due to the presence of bioactive compounds such as flavonoids and phenolic acids. Therefore, exploring the erectogenic potentials of the peels will translate to conversion of the wastes to therapeutic products.

Synergy Between Sildenafil and Topically Delivered Nitric-oxide in Eliciting an Erectile Response in a Rat Model of Radical Prostatectomy

ABSTRACT Introduction Sildenafil belongs to a group of phosphodiesterase-type-5-inhibitors (PDE5i) which represent the only class of FDA-approved oral treatments for erectile dysfunction (ED). However, because their mode of action is dependent on the production of nitric oxide (NO) from nerve endings, patients that undergo radical prostatectomy (RP), which results in cavernous nerve (CN) injury, are commonly refractory to these pharmacologic agents. Objective Our goal was to investigate the ability of topically applied microparticles capable of transdermal delivery of NO (NO-MP) to act synergistically with sildenafil in eliciting an erectile response in an animal model of RP. Methods As a model of RP, Sprague-Dawley rats underwent bi-lateral transection of the CN one-week prior to determining erectile response to treatment. Rats were treated by oral gavage of 0.05 and 0.005 mg sildenafil/kg, 30 minutes before being anesthetized for the determination of intracorporal pressure (ICP) and systemic blood pressure (BP). Baseline ICP and BP were recorded for 30 min, at which time 250 or 100 mg NO-MP (or control, blank-MP) were applied to the rat penile shaft. The ICP and systemic BP were used to determine the time to the first erectile response, duration of the erectile responses, the maximal and average ICP/BP responses and the number of spontaneous erections per hour. Results Although oral treatment with sildenafil by itself resulted in no observable erectile response, topical application of NO-MP in combination with sildenafil resulted in both a faster time to the first erectile response and greater numbers of spontaneous erections compared to NO-MP used alone. Combination of orally administered 0.05 sildenafil/kg with topical application of 250mg NO-MP, compared to 250 mg NO-MP by itself, resulted in significantly more spontaneous erections (4.6 compared to 2 erections per hour, t-test; p-value = 0.043), with a significantly faster onset for the first erectile response (11 compared to 22 minutes; t-test, p-value = 0.041). Conclusions Although knowledge of the molecular pathways that lead to an erection provide a rationale for a synergistic effect between PDE5i and NO in eliciting an erectile response, our results provide the first evidence of such synergy. When combined with the NO-MP, this synergy in eliciting an erectile response was seen with 0.05 mg sildenafil/kg, which would be equivalent to a clinical dose of approximately 2.5 mg sildenafil for an 80 kg patient. Our results suggest a novel treatment strategy for patients with ED following RP whereby an oral PDE5i is used in combination with therapeutics that topically deliver NO to corporal tissue and also the potential to lower the therapeutic dose of oral PDE5i in all patients where it is used for the treatment of ED. Disclosure Yes, this is sponsored by industry/sponsor: ZyloTherapeutics, Inc. Clarification Industry funding only - investigator initiated and executed study Any of the authors act as a consultant, employee or shareholder of an industry for: ZyloTherapeutics, Inc

Dual Strategy with Intracavernosal Implantation of Adipose-derived Stem Cells and Daily Oral L-arginine Optimize Recovery of and Cavernosal Functions after Cavernous Nerve Injury in Rats

ABSTRACT Introduction Radical prostatectomy for prostate cancer has a significant potential role in inducing cavernous nerve injury (CNI). Increasing hypoxia and fibrosis induces destructive changes within cavernous vasculature. Adipose-derived stem cells (ADSCs) can maintain self-renewal and enhanced multi-differentiation potential through the release of a variety of paracrine factors and extracellular vesicles, allowing to repair damaged tissues. Considerable attention has increasingly been paid to their application in tissue engineering and regeneration. In addition, ADSCs can be obtained with a minimally invasive procedure and easily expanded in vitro with low immunogenicity. Nitric oxide (NO) is synthesized from the amino acid L-arginine by a family of enzymes, the nitric oxide synthases (NOS). Orally administered L-arginine enhances the erectile response presumably by stimulating NO production by the corporal tissues increasing cGMP production. Objective To evaluate the efficacy and tolerability of ADSCs and daily oral L-arginine alone or combination in treating rats with bilateral CNI (BCNI)-induced ED. Methods Adult Sprague-Dawley rats (n = 35) were divided into five groups: 1) control; 2) BCNI (4-wk); 3) BCNI+ADSCs (1 × 106 cells by intracavernosal injection); 4) BCNI+ L-arginine (4wk,10 mg/kg/day, oral); and 5) combination treatment with ADSCs and L-arginine in BCNI. Rats in the ADSCs treatment groups were subjected to intracavernosal injection after BCNI. In vivo erectile response was measured by CN stimulation. The relaxant and contractile responses were also detected on in vitro preparations of corpus cavernosum (CC) strips. The expression and localization of neuronal (nNOS), endothelial NOS (eNOS) as well as hypoxia (hypoxia-inducible factor-1α, HIF-1α), fibrosis [transforming growth factor-beta 1 (TGF- β1)]and apoptosis (Bax and Bcl-2) markers were determined using Western blotting and immunohistochemistry. The relative area of smooth muscle to collagen was measured using Masson trichrome staining. Results Rats with CNI had the lowest ICP/MAP ratio at 63% and total ICP at 55% for 7.5 V (P &amp;lt; .001 vs controls) as well as in vitro electrical field stimulation-induced relaxant response at 10% (P &amp;lt; .05 vs controls) and endothelium-dependent acetylcholine-caused relaxation at 56% (P &amp;lt; .001 vs controls). The combined treatment showed more significantly improved erectile and relaxant responses more effectively than ADSCs or L-arginine treatment alone. Increased in the expressions of nNOS, HIF-1α, Bax, and Bcl-2 in the BCNI group were restored by all treatment regiments. eNOS and TGF- β1 protein expressions were similar among groups. Mono-treatment partially improved decreased smooth muscle mass while combined therapy completely recovered. Conclusions The intracavernous injection of ADSCs and oral administration of L-arginine, and, importantly, their combination could effectively protect against hypoxia-induced neurotoxicity, via their increasing endothelial cell function and smooth muscle content, anti-inflammatory, anti-apoptotic, anti-fibrotic properties in addition to reversing erectile function in the BCNI rat model. HIF-1α overexpression by the inhibition of the apoptotic pathway with the Bcl-2 family may have protective effects on the survival of cavernosal neurons. Disclosure No

Treatment with levothyroxine and testosterone ameliorated erectile dysfunction in rat model of propylthiouracil-induced hypothyroidism

ABSTRACT Introduction The endocrine disease frequently interrupts sexual function, and sexual dysfunction may signal serious endocrine disease. Recent studies have claimed an association with hypothyroidism, low testosterone (T) levels and erectile dysfunction (ED), but causality is unclear. There is no study on the experimental model of hypothyroidism that was induced in rats by administration of propylthiouracil (PTU). Objective The purpose of this study was to investigate the deleterious effects of PTU-induced hypothyroidism on ED and T levels. In addition, Levothyroxine is known worldwide as the most common and least effective drug for controlling hypothyroidism. Methods Adult Sprague-Dawley rats (n = 35) were divided into five groups; control, PTU-induced hypothyroidism, PTU+ Levothyroxine, PTU+ Sustanon (a mixture of 4 types of T: propionate, phenylpropionate, isocaproate, decanoate) and PTU+ Levothyroxine + Sustanon. PTU was given in drinking water (0.05%) for 6 weeks. 4 weeks after the beginning of PTU treatment, Levothyroxine (20 mg/kg/day, oral) and Sustanon (10 mg/kg, I.M., once/week) were given for 2 weeks. Serum levels of total T, triiodothyronine (T3) and thyroxine (T4) were determined. The ratio of intracavernosal pressure (ICP) to mean arterial pressure (MAP) and total ICP were measured by cavernous nerve stimulation. The relaxant and contractile responses were evaluated on in vitro preparations of corpus cavernosum (CC) strips. The expression and localization of neuronal (nNOS), endothelial NOS (eNOS) and phosphodiesterase type 5 (PDE5) were determined using Western blotting and immunohistochemistry. The relative area of smooth muscle to collagen was measured using Masson trichrome staining. Results The rat model of hypothyroidism showed a significant decline in serum levels of total T, T3 and T4. Levothyroxine increased T3 and T4 levels while Sustanon normalized only total T levels. In addition, combined treatment of Levothyroxine and Sustanon enhanced all hormone levels. Rats with hypothyroidism displayed the lowest ICP/MAP ratio and total ICP for 7.5 V (P &amp;lt; .001 vs controls). Combined treatment returned reduced ICP/MAP and total ICP responses, while partial amelioration was observed after Levothyroxine and Sustanon treatment alone. In vitro endothelium-dependent acetylcholine-caused relaxation at 1 nM (P &amp;lt; .001 vs controls), electrical field stimulation-induced relaxant response at 20 Hz (P &amp;lt; .001 vs controls) and sildenafil-induced relaxation at 10 µM (P &amp;lt; .05 vs controls) were decreased in the CC strips from hypothyroid rats. The treatment with Levothyroxine and Sustanon increased the reduction in relaxation responses. Decreased in the expressions of eNOS and nNOS and increased in the expressions of PDE5 in the hypothyroid group were restored by Levothyroxine and Sustanon. Mono-treatment partially enhanced reduced smooth muscle mass while combined therapy completely recovered. Conclusions These results show that hypothyroidism adversely affects T levels and erectile responses via decreasing neurogenic and endothelium-dependent relaxation responses which were reversed by the combination therapy with Levothyroxine and Sustanon. Even though the associated alterations in T levels, ED and its reversibility indicate an exact role of thyroid hormones in the erection physiology. Disclosure No

Characteristics of Patients with Erectile Complaints Referred to a Center of Excellence – Defining Complex Erectile Dysfunction

ABSTRACT Introduction The prevalence of erectile complaints in the US is estimated to be more than 50%. Most of the time ED complaints are evaluated and treated in the primary care setting. However, when first line measures are not efficient, patients are referred to general Urologists or to a specialized center. Objective The primary aim of this study is to describe the characteristics of patients referred to a tertiary center for evaluation of erectile complaints not responding to traditional first line therapies and, or patients with an associated complaint of penile deformity (rule out Peyronie's Disease/PD). Methods We retrospectively analyzed a cohort of patients between 2005 and 2019, detailing primary complaints, sexual histories, self-assessment scores, medical history and results of in office intracavernous injection followed by Color Doppler Duplex Ultrasound (CDDU). CDDU findings were recorded following injection of low dose alprostadil (10-20 mcg) and again after a period of privacy and visual sexual stimulation. CDDU findings including peak systolic velocities (PSV), and resistive indices (RIs) were recorded. Arterial insufficiency (AI) was defined as either a post-stimulation PSV &amp;lt; 25 (severe) or a PSV 25-34.9 with RI ≥ 0.9 (moderate). Cavernous venous occlusion disease (CVOD) was defined as post-stimulation PSV ≥35 with RI &amp;lt; 0.9. Vascular normal was defined as post-stim PSV ≥ 35 with RI ≥ 0.9. Results A total of 1490 patients with a median age of 60 (range, 18 – 88), median BMI of 28.4 (range, 15.9 – 56.8) and median Sexual Health Inventory for Men (SHIM) score of 10 (range, 0-25). In our cohort, 257/1489 (17.3%) patients had heart disease, 656/1489 (44.1%) patients had hypertension, 520/1489 (34.9%) patients had diabetes, and 203/1488 (13.6%) patients had a past medical history of hypertriglyceridemia. Smoking history was present in 853/1478 (57.7%) of patients and complaint of PDE-5 failure was made by 945/1201 (78.7%) patients who reported using it. 900 patients (60.4%) had a complaint of penile deformities and ED, 461 (30.9%) had a complaint of ED only, and 129 (8.7%) had a complaint of PD only. Prostate surgery history was noted in 316 men: radical retropubic prostatectomy 108, robotic assisted prostatectomy 134 and endoscopic resection or enucleation 74. Following CDDU we confirmed 767 (51.5%) patients with both ED and PD, 351 (23.6%) with ED only, and 310 (20.8%) PD only. We found 62 men (4.2%) had normal vascular erectile response to low dosage PGE1 (diagnosed as psychogenic ED vs. post-prostatectomy neurogenic ED). Among the 351 patients with ED only on Doppler, 132 (37.6%) had AI, 124 (35.3%) had CVOD, and 95 (27.1%) had a mixed vascular diagnosis. Among patients with vascular ED on diagnoses by CDDU, 73/351 (20.8%) had heart disease, 192/349 (55.0%) had smoking history, 273/311 (87.8%) complained of PDE5-inhibitor failure, 130/351 (37.0%) had diabetes, and median SHIM score was 7 (range 1-25). Conclusions This summary describes the characteristics in 1490 men who presented for evaluation of erectile complaints and or complaints of penile deformity to a tertiary care center. Patients referred to Urologists have complex ED, defined as refractory to PDE5-Inhibitors, associated with penile deformities, and multiple medical / surgical risk factors. Disclosure No

Intracavernosal OnabotulinumtoxinA Exerts a Synergistic Pro-Erectile Effect When Combined With Sildenafil in Spontaneously Hypertensive Rats

Botulinum toxin A (BTX-A) has a variety of uses in medicine. Some evidence suggests that intracavernosal (ic) BTX-A injection administered in addition to phosphodiesterase type 5 inhibitors (PDE5-Is) could effectively treat erectile dysfunction (ED) in insufficient responders to PDE5-Is. To provide experimental pharmacological evidence for the use of onabotulinumtoxinA ic alone or in combination with PDE5-Is for difficult-to-treat ED. We thus compared the effects of BTX-A ic alone and BTX-A ic combined with PDE5-I iv, and a placebo treatment ic or iv. Erectile function was evaluated following cavernous nerve electrical stimulation (6 V, 1-millisecond pulse, 45-second duration) at different frequencies (0, 2, 3, 4, 5, 7.5, and 10 Hz) in 4 groups (n = 8 / group) of anesthetized, spontaneously hypertensive rats, a robust animal model of ED of vascular origin. Rats were treated by onabotulinumtoxinA 10U or saline ic 1 week prior to erectile function testing and sildenafil (0.3 mg/kg) or saline iv 4 minutes prior to testing. Frequency-response curves were compared with a 2 way ANOVA. Both onabotulinumtoxinA ic, and sildenafil iv significantly improved erectile responses in spontaneously hypertensive rats, however the effect was greatly amplified when the treatments were combined. Intracavernosal pressure and/or mean arterial pressure ratios were significantly increased by sildenafil and onabotulinumtoxinA ic versus the control condition. OnabotulinumtoxinA 10U ic combined with sildenafil iv significantly potentiated erectile responses. Area under the curve and/or mean arterial pressure ratio increased by 19% with sildenafil iv, by 15% with onabotulinumtoxinA ic and by 58% with the combined treatment following cavernous nerve electrical stimulation at 6V, 1 ms, 10 Hz: these stimulation parameters elicited the maximal erectile response. These data provide a pharmacological rationale for the combined administration of onabotulinumtoxinA ic and sildenafil iv since the effects of both treatments were potentiated when their administration was combined. First evidence of a synergistic pro-erectile effect of BTX-A combined with PDE5-I, however the mechanism behind the pro-erectile effect of BTX-A ic remains hypothetical. These results support further studies into the mechanisms behind the pro-erectile effect of BTX-A ic, as well as multicenter randomized control trials to evaluate the safety and efficacy of BTX-A ic combined with sildenafil for difficult-to-treat ED.

Angiotensin-(1−7) improves diabetes mellitus-induced erectile dysfunction in rats by regulating nitric oxide synthase levels

This study explores the role of inducible nitric oxide synthase (iNOS) in the pathogenesis of diabetes mellitus-induced erectile dysfunction (DMED) and the effect of angiotensin 1–7 (Ang- [1–7]) on NOS levels. A type 2 diabetes mellitus (DM) rat model was established. Erectile function was assessed by measuring intracavernous pressure and mean arterial pressure after electrical stimulation. The expression of iNOS, endothelial NOS (eNOS), eNOS phosphorylated at Ser 1177 (p-eNOS [Ser 1177]), and AKT/p-AKT in corpus cavernosum smooth muscle cells (CCSMCs) was measured by Western blotting and immunofluorescence. The plasma levels of NO, SOD, malondialdehyde, and peroxynitrite were calculated. Intracellular calcium content was determined by flow cytometry. DMED rats exhibited decreased erectile function and severe oxidative stress. Ang-(1−7) treatment improved erectile response and suppressed oxidative stress by upregulating p-eNOS/eNOS and downregulating iNOS levels. Silencing iNOS in CCSMCs decreased oxidative stress and intracellular calcium levels induced by high glucose. In turn, iNOS overexpression increased oxidative stress and intracellular calcium level. Treatment with the MAS receptor antagonist A779 and the Akt antagonist LY294002 reversed the effects of Ang-(1−7) on iNOS. Ang-(1−7) improved DMED through the MAS/AKT signaling pathway.

Upregulated IGFBP3 with Aging Is Involved in Modulating Apoptosis, Oxidative Stress, and Fibrosis: A Target of Age-Related Erectile Dysfunction.

Aging has been deemed the primary factor in erectile dysfunction (ED). Herein, age-related changes in the erectile response and histomorphology were detected, and the relationship between aging and ED was investigated based on gene expression levels. Thirty male Sprague–Dawley (SD) rats were randomly divided into 6 groups, and intracavernous pressure (ICP) and mean arterial pressure (MAP) were measured. Subsequently, the corpus cavernosum (CC) was harvested and prepared for histological examinations of apoptosis, oxidative stress (OS), and fibrosis. Then, the microarray dataset (GSE10804) was analyzed to identify differentially expressed genes (DEGs) in ED progression, and hub genes were selected. In addition, aged CC smooth muscle cells (CCSMCs) were isolated to evaluate the function of the hub gene by siRNA interference, qRT–PCR, immunofluorescence staining, enzyme-linked immunosorbent assay, western blot analysis, CCK-8 assay, EdU staining, and flow cytometry approaches. The ICP/MAP and smooth muscle cell (SMC)/collagen ratios declined with aging, while apoptosis and OS levels increased with aging. The enriched functions and pathways of the DEGs were investigated, and 15 hub genes were identified, among which IGFBP3 was significantly upregulated. The IGFBP3 upregulation was verified in the CC of aging rats. Furthermore, aged CCSMCs were transfected with siRNA to knock down IGFBP3 expression. The viability and proliferation of the CCSMCs increased, while apoptosis, OS, and fibrosis decreased. Our findings demonstrate that the erectile response of SD rats declines in parallel with enhanced CC apoptosis, OS, and fibrosis with aging. Upregulation of IGFBP3 plays an important role; furthermore, downregulation of IGFBP3 improves the viability and proliferation of CCSMCs and alleviates apoptosis, OS, and fibrosis. Thus, IGFBP3 is a potential therapeutic target for age-related ED.

Restoring erectile function by combined treatment with JNK inhibitor and HDAC inhibitor in a rat model of cavernous nerve injury.

The main pathophysiologic conditions of erectile dysfunction (ED) after radical prostatectomy are considered to be corporal fibrosis and apoptosis induced by cavernosal nerve (CN) injury. In a rat model of CN crush injury (CNCI), we investigated whether combination treatment with JNK inhibitor (JNKi), SP600125, and HDAC inhibitor (HDACi), suberoylanilide-hydroxamic-7 acid (SAHA), for 2weeks after CNCI would restore erectile function by suppressing fibrosis and apoptosis through normalization of JNK and HDAC pathways. Seventy 12-week-old rats were randomly divided into five groups: Sham surgery, CNCI alone, CNCI treated with daily intraperitoneal injection of 10mg/kg JNKi, CNCI treated with daily oral administration of 25.0mg/kg HDACi, and CNCI daily treated with a combination. Two weeks after CNCI, we investigated the erectile response to electrostimulation and conducted histological staining, caspase-3 activity assay, and western blot analysis. CNCI alone resulted in significantly reduced intracavernosal pressure/mean arterial pressure (MAP) and area under the curve/MAP, decreased smooth muscle (SM)/collagen ratio and SM content, higher caspase-3 activity, and increased protein levels of total HDAC3, transforming growth factor (TGF)-β, fibronectin, and c-Jun phosphorylation, compared with the Sham surgery. The CNCI groups exposed to JNKi, HDACi or both showed improvements in erectile-responses and SM/collagen ratio, compared to the CNCI alone. The combined treatment showed additional improvement in erectile responses at 1.0V stimulation and in SM/collagen ratio compared to the single agent treatment. SM content, caspase-3 activity, and c-Jun phosphorylation improved in the two CNCI groups exposed to JNKi. The two CNCI groups exposed to HDACi showed normalization of protein levels of HDAC3, fibronectin, and TGF-β. The combined administration of JNKi and HDACi during the acute phase after CNCI in rats can preserve ED by suppressing cavernosal fibrosis and apoptosis by normalizing the HDAC/TGF-β and JNK pathways.

A novel approach to treating erectile dysfunction with a light-controlled nitric oxide donor

It has long been known that nitric oxide (NO) is involved in the initiation and maintenance of erection. For this reason, NO supplementation has been considered a useful target for the treatment of erectile dysfunction (ED), and many studies have been conducted. However, to date, no compounds have been launched for a variety of reasons. One of the reasons is the systemic adverse reactions. In order to solve this problem, we focused on light-controlled NO donors and investigate their potential application in ED treatment. Light-controlled NO donors have three main characteristics: first, they release NO only at the site of light irradiation, second, they release NO only during the time of light irradiation, and third, the amount of NO released can be controlled according to the light intensity. These features suggest that light-responsive NO donors may be useful for ED therapy. Our group has been working on the development of light-controlled NO donors, and has so far developed the blue light-controlled NO donor "NOBL-1", the yellowish-green light-controlled NO donor "NO-Rosa", and the red light-controlled NO donor "NORD-1". Our recent studies have shown that NORD-1 and red light can enhance the erectile response in rats at the in vivo level. Next, we examined the effects of NORD-1 and red light using a neurogenic ED model, which is believed to be less effective than existing ED drugs. The results showed that red light irradiation after NORD-1 administration enhanced the erectile response and improved ED in the neurogenic ED model. These results suggest that NORD-1, a light-controlled NO donor, and red light can enhance the erectile response in rats and may have potential as an ED drug. Although optimization of the compound is essential, it is expected that a new therapeutic approach called photobiotherapy for ED will be developed in the future.

Low-intensity shockwave treatment (LISWT) improves penile rigidity in eugonadal subjects with erectile dysfunction: a pilot study.

Since low-intensity shockwave treatment (LISWT) has putative effects on penile hemodynamics remodeling, the aim of this study was to evaluate any improvement of penile vascular flows after LISWT treatment in patients with erectile dysfunction (ED) and poor response to PDE5i. Twenty-one eugonadal patients with different ED severity underwent 6 weekly LISWT sessions (1500-4000 pulses) after 2 weeks withdrawal from PDE5i assumption. Once daily Tadalafil (2.5 mg daily) was reintroduced 4 weeks apart from LISWT termination and patients were evaluated at 1, 2 and 6 months follow-up (T1, T2, T6) by the International Index of Erectile Function-15 items questionnaire (IIEF-15) erectile function (EF) domain, Erection Hardness Score (EHS) and Global Assessment Questionnaires (GAQ). Basal Penile Color-Doppler Ultrasound parameters in the flaccid state (B-PCDU) were evaluated before, during and after interventional protocol. Mean EHS score improved in 35% of patients at T1, and in up to 50% of patients at T2 and T6 follow-up visits (P<0.05). We found 25% improvement of EF scores at T1 session, 43.75% at T2 and 62.5% at T6, respectively (P<0.05). No statistically significant differences in flow parameters, EF-domain and testosterone levels were found when baseline and last observation carried forward (LOCF) parameters were compared. The GAQ questionnaire scored higher satisfaction rates either at the end of the treatment (100%), or at LOCF (92.5%). Despite the study limitations with respect to B-PCDU in this setting, our results confirm a trend toward improvement of erectile questionnaire scores after LISWT with higher overall satisfaction rates among patients with ED. We conclude that LISWT may be an effective option in some difficult-to-treat patients with ED by improving the erectile response to PDE5i.