Pathophysiology and treatment of diabetic erectile dysfunction

Managing Sexual and Reproduction Complications of Diabetes in Men

Male reproductive disorders are a less discussed complication of diabetes. These disorders can include balanitis, erectile dysfunction, decreased libido, erectile impotence, and infertility. This article reviews the epidemiology, pathophysiology, classic presentation, and treatment of balanitis, erectile dysfunction, and sperm dysfunction.

Traditional chinese medicine to prevent and treat diabetic erectile dysfunction

Diabetic erectile dysfunction (DED) is one of the most common complications of diabetes mellitus. However, current therapeutics have no satisfactory effect on DED. In recent years, traditional Chinese medicine (TCM) has shown good effects against DED. By now, several clinical trials have been conducted to study the effect of TCM in treating DED; yet, the underlying mechanism is not fully investigated. Therefore, in this review, we briefly summarized the pathophysiological mechanism of DED and reviewed the published clinical trials on the treatment of DED by TCM. Then, the therapeutic potential of TCM and the underlying mechanisms whereby TCM exerts protective effects were summarized. We concluded that TCM is more effective than chemical drugs in treating DED by targeting multiple signaling pathways, including those involved in oxidation, apoptosis, atherosclerosis, and endothelial function. However, the major limitation in the application of TCM against DED is the lack of a large-scale, multicenter, randomized, and controlled clinical trial on the therapeutic effect, and the underlying pharmaceutical mechanisms also need further investigation. Despite these limitations, clinical trials and further experimental studies will enhance our understanding of the mechanisms modulated by TCM and promote the widespread application of TCM to treat DED.

Poststroke Erectile Dysfunction in Cameroon: Prevalence, Associated Factors, and Quality of Life

Background

Stroke is a severe disease due to its morbidity-mortality. It is the first cause of acquired disability including erectile dysfunction (ED). The purpose of this study was to determine the prevalence of ED in stroke patients at the Douala General Hospital, to identify associated factors and to evaluate their quality of life.

Materials and Methods

A cross-sectional study was conducted over a period of seven months from November 2016 to May 2017 on two groups of patients in neurology, cardiology, and endocrinology units of the Douala General Hospital (Cameroon): stroke patients (stroke+) and nonstroke patients (stroke-). We collected sociodemographic and clinical data using a preestablished questionnaire. Erectile function was assessed using International Index of Erectile Function (IIEF-5). Associated and predictive factors were determined using univariate and multivariate analyses. Results were significant for a p value < 0.05.

Results

A total of 269 patients were included, among them 87 stroke+ (32.34%) and 182 stroke- (67.66%) (controlled group). The mean age was 56.37 ± 12.89 years and 57.18 ± 10.24 years of stroke+ and stroke-, respectively (p = 0.608). Prevalence of poststroke ED was 64.4% (OR = 3.41, 95% CI: 1.99-5.82, p < 0.001). The average time of occurrence of the poststroke ED was 5 ± 5.85 months. Diabetes and dyslipidemia were the predictive factors of occurrence of poststroke ED. Depression was found both in stroke+ with ED and stroke+ without ED with no difference (p = 0.131).

Conclusion

About two-thirds of stroke patients developed ED. Diabetes and dyslipidemia were predictive factors of ED in stroke patients.

miR-195-5p Regulates the Phenotype Switch of CCSM Cells by Targeting Smad7

Introduction

Phenotype switch refers to the process in which smooth muscle cells change from contractile type to synthetic type and acquire the ability of proliferation. Phenotypic transformation involves many changes of cell function, such as collagen deposition and fibrosis, which affect the normal erectile function of penis.

Aim

To investigate the role of miR-195-5p in regulating the Phenotype switch of the corpus cavernosum smooth muscle (CCSM) cells.

Methods

A small mother against decapentaplegic 7(Smad7) virus vector and a miR-195-5p mimics or an si-Smad7 viral vector and a miR-195-5p inhibitor were transfected into CCSM cells. The cells were obtained by primary culture of rat corpus cavernosum smooth muscle tissue. Real-time polymerase chain reaction (PCR) experiments, Western blotting, hematoxylin-eosin (HE) staining, transwell experiments, MTT assays, and flow cytometry were used to detect miR-195-5p, Smad7, phenotype switch markers of CCSM cells and related protein expression, as well as changes in cell morphology, migration, proliferation and apoptosis.

Main Outcome Measure

To study the regulation of miR-195-5p in CCSM cells by overexpression and silencing strategies.

Results

Overexpressed miR-195-5p promoted the transformation of CCSM cells from a contractile type to a synthetic type. Meanwhile, the migration ability and proliferation ability of CCSM cells increased, and the apoptosis rate decreased. The expression-silencing of miR-195-5p gave rise to the opposite effect. The results of the rescue experiment demonstrated that overexpressed Smad7 rescued the inhibitory of the switch of the CCSM cell phenotype from the contractile type to the synthesis type caused by overexpression of miR-195-5p alone. Moreover, the enhancement effect of the migration ability and proliferation ability of CCSM cells was also eliminated, and the apoptosis rate was increased. Silencing miR-195-5p and Smad7 at the same time resulted in the opposite effect.

Conclusion

miR-195-5p may regulate the phenotype switch of CCSM cells by targeting Smad7.

Zhang J, Zhang X, Zhang J, et al. miR-195-5p Regulates the Phenotype Switch of CCSM Cells by Targeting Smad7. Sex Med 2021;9:100349.

Mesenchymal Stem Cell Exosomes as a New Strategy for the Treatment of Diabetes Complications

Diabetes mellitus (DM) is a metabolic disease, now prevalent worldwide, which is characterized by a relative or absolute lack of insulin secretion leading to chronically increased blood glucose levels. Diabetic patients are often accompanied by multiple macrovascular complications, such as coronary heart disease, hypertension, macrovascular arteriosclerosis, and microvascular complications. Microvascular complications include diabetic kidney injury, diabetic encephalopathy, and diabetic foot, which reduce the quality of life and survival status of patients. Mesenchymal stem cell exosomes (MSC-Exos) possess repair functions similar to MSCs, low immunogenicity, and ease of storage and transport. MSC-Exos have been proven to possess excellent repair effects in repairing various organ damages. This study reviews the application of MSC-Exos in the treatment of DM and its common complications. MSC-Exos may be used as an effective treatment for DM and its complications.

Effects of Cultured Cordycep militaris on Sexual Performance and Erectile Function in Streptozotocin-Induced Diabetic Male Rats

Cordyceps militaris (CM), a valuable edible and medicinal fungus, has been used as traditional medicine to treat health conditions, as well as hyposexuality in Asian societies for over a century. Due to the high demand, several artificial cultivation methods have been developed for their biological activities. In this study, CM was cultured on medium that contained white rice and silkworm pupae, and the levels of cordycepin and adenosine, as well as its aphrodisiac effects in diabetes-induced erectile dysfunction (DIED), were evaluated. Diabetic rats were induced by streptozotocin (STZ) injection and administered orally with CM (0.1, 0.5, and 1.0 g/kg BW/day) for 3 weeks. Diabetic rats in negative and positive control groups received vehicle and sildenafil citrate (5 mg/kg), respectively. Results showed the changes in mating behaviour in which mount latency and intromission latency were significantly increased in diabetic rats, compared with the normal control group. Diabetic rats also showed a significant reduction in intracavernosal pressure (ICP) response to cavernous nerve stimulation, sperm count, testosterone level, penile nitric oxide synthase (NOS), and testicular superoxide dismutase (SOD) activities, when compared to the normal control group. Administration of CM (0.1, 0.5, and 1.0 g/kg BW/day) reversed the effects of diabetes on the mating behaviour, and the ICP responses to electrical stimulation. Moreover, the levels of penile NOS, testicular SOD activities, testosterone, and sperm count were significantly increased, and testicular malondialdehyde (MDA) levels were significantly decreased in these treated diabetic rats. Diabetic rats treated with sildenafil showed a significant induction in intromission frequency and NOS and SOD activities, as well as a marked increase in ICP responses. These results suggest that CCM exerts its aphrodisiac effect, possibly through activating testosterone production and suppressing oxidative stress to enhance erectile function in diabetic rats.

Harnessing Stem Cell Potential for the Treatment of Erectile Function in Men with Diabetes Mellitus: From Preclinical/Clinical Perspectives to Penile Tissue Engineering

Background::

According to the World Health Organization, more than 150 million people are diabetic, and this number will increase twofold by the year 2025. Diabetes-related complications affect all body organ systems, including the penis. Diabetes-induced Erectile Dysfunction (ED) is caused by neuropathy of the penile nerves and vasculopathy involving the smooth muscle and endothelium of the corpus cavernosum.

Objective::

This study aims to present an overview of Stem Cell (SC) research in diabetic animal models of ED, focusing on the function, signaling, and niches that have a prominent role in the regeneration of cavernosal cells and penile tissues. We highlight common erectile pathologies caused by diabetes and review relevant preclinical trials. We also discuss paracrine mechanisms of various SC therapies involved in the repair of endothelial cells and cavernous nerves in these diabetic models.

Method::

A PubMed search was performed, with dates ranging from inception until Mar 31, 2019.

Results::

This review provides a comprehensive evaluation of the various strategies that have been investigated for improving SC delivery methods, through preclinical literature and published clinical trials regarding ED in men with diabetes. Various cell-type applications have benefited erectile function in diabetic models of ED.

Conclusion::

This review examines the progress and remaining challenges in diabetes-related SC research regarding ED. Moving forward, it is only with a combined effort of basic biology and translational work that the potential of SC-based therapies in diabetes in ED can be realized.

Exosomes from adipose-derived stem cells protect against high glucose-induced erectile dysfunction by delivery of corin in a streptozotocin-induced diabetic rat model

Introduction

Increasing study have found that stem cell transplantation have a therapeutical effect to diabetes mellitus (DM)-induced erectile dysfunction (ED). So, the aim of this study was to evaluate the beneficial effect of corin from adipose-derived stem cells (ADSCs) on DM-induced ED.

Methods

Exosomes were isolated from ADSCs (ADSC-EXOs) or from ADSCs in which corin gene expression was silenced by siRNA (siCorin). For in vivo studies, rats with streptozotocin-induced DM were intravenously injected with ADSC-EXOs or siCorin-ADSC-EXOs. Two weeks later, intracavernosal pressure (ICP) and mean arterial pressure (MAP) were measured to assess erectile function, and penile tissues were harvested for further evaluation of levels of inflammatory factors and expression of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and neuronal nitric oxide synthase (nNOS). We also evaluated the recovery of neurovascular function in penile tissues by immunofluorescence analysis.

Results

The results showed that ADSC-EXOs restored erectile function in diabetic rats, as determined by the ICP/MAP ratio. Exosomes from ADSCs also promoted neurovascular function and suppressed expression of inflammatory factors. In contrast, the decreased content of corin in exosomes after silencing corin in ADSCs reduced the therapeutic effect of exosomes on ED.

Conclusion

These findings demonstrated the therapeutic mechanism underlying the use of ADSC-EXOs for treating ED and the beneficial effect of corin.

Eucommia ulmoides Oliv. Leaf Extract Improves Erectile Dysfunction in Streptozotocin-Induced Diabetic Rats by Protecting Endothelial Function and Ameliorating Hypothalamic-Pituitary-Gonadal Axis Function

Erectile dysfunction (ED) is a major complication of diabetes mellitus. Eucommia ulmoides Oliv. is used as a traditional medicine for male impotence, but no systematic study has examined its effect on diabetes-associated ED. In this study, we investigated the effects of Eucommia ulmoides Oliv. leaf extract (EULE) on restoring erectile function in streptozotocin (STZ)-induced diabetic rats model. After 16 weeks of treatment, EULE administration had significantly increased intracavernosal pressure, nitric oxide (NO) levels, and cyclic guanosine monophosphate (cGMP) concentrations. Serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels were markedly higher and serum malondialdehyde (MDA) levels were lower in the EULE-treated groups than in the diabetic model group. EULE restored NO biosynthesis by significantly increasing protein kinase B (Akt) and endothelial NO synthase (eNOS) activation. Furthermore, EULE is likely to benefit the hypothalamic-pituitary-gonadal (HPG) axis, as it increased gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone (T) concentrations as well as hormone receptors Gnrhr, Fshr, and Lhr expression levels. Hence, EULE attenuates oxidative stress, increases NO production, and activates the Akt-eNOS pathway to restore endothelial function; moreover, EULE enhances the HPG axis to improve erectile function. These results suggest that EULE may represent a new therapeutic avenue for diabetes-associated ED.

Traditional Chinese medicine on treating diabetic mellitus erectile dysfunction: Protocol for a systematic review and meta-analysis

BACKGROUND

Diabetic mellitus erectile dysfunction (DMED) refers to erectile dysfunction (ED) secondary to diabetes. As people's lifestyle changes and the population ages, the incidence of DMED continues to increase. Many clinical trials have proven that Chinese medicine has a significant effect in the treatment of DMED. In this systematic review, we aim to evaluate the effectiveness and safety of traditional Chinese medicine (TCM) for DMED.

METHODS

We will search PubMed, Cochrane Library, AMED, EMbase, WorldSciNet; Nature, Science online and China Journal Full-text Database, China Biomedical Literature CD-ROM Database, and related randomized controlled trials included in the China Resources Database. The time is limited from the construction of the library to February, 2019.We will use the criteria provided by Cochrane 5.1.0 for quality assessment and risk assessment of the included studies, and use the Revman 5.3 and Stata13.0 software for meta-analysis of the effectiveness, recurrence rate, and symptom scores of DMED.

ETHICS AND DISSEMINATION

This systematic review will evaluate the efficacy and safety of TCM for treating Diabetic mellitus erectile dysfunction. Because all of the data used in this systematic review and meta-analysis has been published, this review does not require ethical approval. Furthermore, all data will be analyzed anonymously during the review process trial.

Dyslipidaemia as a risk factor for erectile dysfunction in type 2 diabetes mellitus patients

BACKGROUND

Despite epidemiological studies worldwide have documented erectile dysfunction (ED) as a major complication of type 2 diabetes Mellitus (T2DM) in men, only limited research reported on determinants of ED in this population. The study aimed at examining the association of ED with dyslipidaemia in T2DM patients.

METHODS

The study enrolled 813 consecutive eligible adult male T2DM patients attending the endocrinology departments of a tertiary teaching hospital in Bangladesh. Sexual function was assessed using modified International Index of Erectile Function (IIEF) in face-to-face interview and collected along with sociodemographic information. Diabetes and lipid profile and treatment history were collected from patient's treatment records. Association of ED with dyslipidaemia was assessed using multivariable logistic regression adjusting for potential confounders.

RESULT

Prevalence of ED among the T2DM patients was very high (72.7%), of which around half had moderated-to-severe ED. Odds of having dyslipidaemia among T2DM patients with ED is 2.3 times higher than those without. The odds increased by approximately 3 fold for an abnormal High Density Lipoprotein level and by 2.7 fold for abnormal Low Density Lipoprotein.

CONCLUSION

Dyslipidaemia was associated with increased ED risk among T2DM. Abnormal lipoprotein level particularly were found to pose greater risk.

Comparison of Improving Effects for Diabetic Erectile Dysfunction according to the Anti-Glycemic Agents: Phlorizin and Insulin

Purpose

To compare the improving effects of diabetic erectile dysfunction with two anti-glycemic agents; phlorizin and insulin.

Materials and Methods

Sixty Sprague-Dawley rats were divided into four groups (n=15 in each group): normal control (C), untreated diabetic rats (D), and diabetic rats treated by phlorizin (P) or insulin (I). Ten weeks after the diabetic induction using an injection of streptozotocin (55 mg/kg), four weeks of diabetic control was conducted. Erectile response, Western blot, and immunohistochemistry were assessed.

Results

During the experiment, the C-group showed continuous weight gain, while the other groups suffered from weight loss. After start of diabetic control, the body weight of I-group was increased; whereas, there was no meaningful change in the P-group. Meanwhile, comparable blood glucose levels were achieved in the P- and I-groups. The erectile response was markedly decreased in the D-group, whereas the P- and I-groups were similar as good as the C-group. In addition, D-group showed the significant decrease in the cavernosal smooth muscle content and increased apoptosis. Platelet endothelial cell adhesion molecule-1 protein expression, phosphorylation of endothelial nitric oxide synthase and myosin phosphatase target subunit 1 were significantly distorted in the D-group, while the P- and I-groups were comparable with the C-group.

Conclusions

Phlorizin treatment resulted in the improvement of erectile function as same as insulin despite the lack of anabolic weight gains. These results suggest that control of blood glucose level rather than a type of anti-glycemic agents is more important for the prevention and treatment of diabetic erectile dysfunction

Neuroprotective effects of melatonin on erectile dysfunction in streptozotocin-induced diabetic rats

PURPOSE

To explore the neuroprotective effects and its possible mechanisms of melatonin (MT) on erectile dysfunction in streptozotocin-induced diabetic rats.

METHODS

Twenty-eight Sprague-Dawley rats received intraperitoneal injection of streptozotocin and 8 weeks later, the determined diabetic rats randomly got intraperitoneal injection of phosphate buffer solution (PBS) or MT. Another 12 normal rats received PBS treatment. Four weeks later, intracavernous pressure, mean arterial pressure, pathological changes in penis, and major pelvic ganglion (MPG) were measured. Malondialdehyde, superoxide dismutase, p38 and p-p38 levels in penis were detected.

RESULTS

Diabetic rats showed significant decreases of erectile function accompanied with serious neuropathy in dorsal penile nerve (DPN) and MPG, meanwhile collagen deposition, oxidative stress, and p-p38 levels in penis were elevated. Melatonin treatment partially but significantly improved the erectile function, ameliorated neuropathy in DPN and MPG, and decreased collagen deposition, oxidative stress, and p-p38 levels in diabetic rats.

CONCLUSIONS

Melatonin treatment helps improve erectile function and ameliorate neuropathy and fibrosis in diabetic rats. These may be associated with reductions in oxidative stress, p38MAPK signaling pathway, and neuropathy.

Epalrestat, an Aldose Reductase Inhibitor, Restores Erectile Function in Streptozocin-induced Diabetic Rats

Epalrestat, an aldose reductase inhibitor (ARI), was adopted to improve the function of peripheral nerves in diabetic patients. The aim of this study was to investigate whether epalrestat could restore the erectile function of diabetic erectile dysfunction using a rat model. From June 2016, 24 rats were given streptozocin (STZ) to induce the diabetic rat model, and epalrestat was administered to ten diabetic erectile dysfunction (DED) rats. Intracavernous pressure (ICP) and mean systemic arterial pressure (MAP), levels of aldose reductase (AR), nerve growth factor (NGF), neuronal nitric oxide synthase (nNOS), α-smooth muscle antigen (α-SMA), and von Willebrand factor (vWF) in the corpus cavernosum were analyzed. We discovered that epalrestat acted on cavernous tissue and partly restored erectile function. NGF and nNOS levels in the corpora were increased after treatment with epalrestat. We also found that the content of α-SMA-positive smooth muscle cells and vWF-positive endothelial cells in the corpora cavernosum were declined. Accordingly, epalrestat might improve erectile function by increasing the upregulation of NGF and nNOS to restore the function of the dorsal nerve of the penis.

Icariside II Promotes the Differentiation of Adipose Tissue-Derived Stem Cells to Schwann Cells to Preserve Erectile Function after Cavernous Nerve Injury

Icariside II (ICA II) is used in erectile dysfunction treatment. Adipose tissue-derived stem cells (ADSCs) are efficient at improving erectile function. This study aimed to explore the action mechanism of ADSCs in improving erectile function. ADSCs were isolated from the adipose tissues of rats. Cell proliferation was determined using the Cell Counting Kit-8 (CCK-8) assay. The expressions of mRNA and protein were determined separately through qRT-PCR and western blot. The endogenous expressions of related genes were regulated using recombinant plasmids and cell transfection. A Dual-Luciferase Reporter Assay was performed to determine the interaction between miR-34a and STAT3. Rat models with bilateral cavernous nerve injuries (BCNIs) were used to assess erectile function through the detection of mean arterial pressure (MAP) and intracavernosal pressure (ICP). ICA II promoted ADSCs' proliferation and differentiation to Schwann cells (SCs) through the inhibition of miR-34a. Suppressed miR-34a promoted the differentiation of ADSCs to SCs by upregulating STAT3. ICA II promoted the differentiation of ADSCs to SCs through the miR-34a/STAT3 pathway. The combination of ICA II and ADSCs preserved the erectile function of the BCNI model rats. ADSCs treated with ICA II markedly preserved the erectile function of the BCNI model rats, which was reversed through miR-34a overexpression. ICA II promotes the differentiation of ADSCs to SCs through the miR-34a/STAT3 pathway, contributing to erectile function preservation after the occurrence of a cavernous nerve injury.

Superparamagnetic iron oxide nanoparticle targeting of adipose tissue-derived stem cells in diabetes-associated erectile dysfunction

Erectile dysfunction (ED) is a major complication of diabetes, and many diabetic men with ED are refractory to common ED therapies. Adipose tissue-derived stem cells (ADSCs) have been shown to improve erectile function in diabetic animal models. However, inadequate cell homing to damaged sites has limited their efficacy. Therefore, we explored the effect of ADSCs labeled with superparamagnetic iron oxide nanoparticles (SPIONs) on improving the erectile function of streptozotocin-induced diabetic rats with an external magnetic field. We found that SPIONs effectively incorporated into ADSCs and did not exert any negative effects on stem cell properties. Magnetic targeting of ADSCs contributed to long-term cell retention in the corpus cavernosum and improved the erectile function of diabetic rats compared with ADSC injection alone. In addition, the paracrine effect of ADSCs appeared to play the major role in functional and structural recovery. Accordingly, magnetic field-guided ADSC therapy is an effective approach for diabetes-associated ED therapy.

The Involvement of Corin in the Progression of Diabetic Erectile Dysfunction in a Rat Model by Down-Regulating ANP /NO/cGMP Signal Pathway

This study was aimed to analyze the potential role of Corin in the procession of diabetic ED and to explore the underlying mechanism. Diabetic ED rat model was constructed and the characteristics of diabetic ED and control rats were recorded at 4, 8, 12, and 16 weeks. qRT-PCR and Western bloting were used to detected the mRNA and protein levels. Intracellular cGMP detection was accomplished using a commercial radioimmunoassay method. Vascular endothelial cell from rat corpus cavernosum spiral artery was isolated and transfected with si- Corin to analyzed the potential role of Corin. Cell viability was assessed using crystal violet. The results showed that diabetic ED rats showed significantly higher glucose level, and lower body weight, ICP level, and ICP/MAP ratio at 12 and 16 weeks in diabetic ED rats compared with control rats. The protein levels of Corin, atrial natriuretic peptide (ANP) and eNOS, and the level of cGMP were significantly down-regulated in corpus cavernosum in diabetic ED rats, revealing the potential role of Corin in NO-associated diabetic ED. Further, studies proved that defect of Corin not only inhibited the vascular endothelial cell viability in high-glucose condition, but also suppressed ANP, eNOS, and cGMP expression in vascular endothelial cells. To sum up, Corin contributes to the progression of diabetic ED and the underlying mechanism is associated with the down-regulation of ANP /NO/cGMP signal pathway. J. Cell. Biochem. 118: 2325-2332, 2017. © 2017 Wiley Periodicals, Inc.

Skin autofluorescence (a marker for advanced glycation end products) and erectile dysfunction in diabetes

AIM

Although diabetes-related erectile dysfunction (ED) has many etiological factors, little is known about the putative pathophysiological role of advanced glycation end products (AGEs). Skin autofluorescence is a noninvasive marker of AGEs. Recent studies have evidenced a relationship between skin autofluorescence and several complications of diabetes. We hypothesized that AGEs (assessed by skin autofluorescence) are associated with ED in diabetes patients.

METHODS

Between March 2014 and April 2015, 42 patients with type 1 diabetes (T1D) and 44 patients with type 2 diabetes (T2D) were consecutively enrolled in a descriptive, cross-sectional study and compared to 54 healthy controls. ED was evaluated via the 5-item version of the International Index of Erectile Function (IIEF-5). Skin autofluorescence was measured on the volar aspect of the arm with an AGE-Reader.

RESULTS

Patients with diabetes had a mean±standard deviation age of 50±15 and a mean duration of diabetes of 16±12years. Skin autofluorescence was strongly and significantly correlated with the IIEF-5 score in the T1D subgroup (r=-0.52; P=0.004), the T2D subgroup (r=-0.32; P<0.03) and in the whole group of diabetic patients (r=-0.49; P<0.0001). In multivariate analyses that controlled for potentially confounding clinical and biochemical factors, only skin autofluorescence was still significantly correlated with the IIEF-5 score (P<0.0001). A receiver operating characteristic analysis revealed that a skin autofluorescence value ≥3.2AU determined severe ED with a sensitivity of 60% and a specificity of 87% in diabetic patients.

CONCLUSION

Skin autofluorescence is significantly associated with ED in diabetes, independently of classical confounding factors.

Role of endothelin receptors and relationship with nitric oxide synthase in impaired erectile response in diabetic rats

To evaluate the protective role of bosentan (BOS), an endothelin-1 (ET-1) receptor antagonist, and to show the changes in rats with experimentally induced diabetic erectile dysfunction (ED), a total of 24 albino Wistar rats were allocated into four groups. Group 1 was the healthy group and Group 2 had diabetes mellitus (DM) induced by intraperitoneal injection of 60 mg kg^-1 streptozotocin (STZ). Following the establishment of DM, Group 3 and Group 4 were treated with oral BOS doses of 50 mg kg^-1 and 100 mg kg^-1 , respectively, for 60 days. At the end of the treatment, we evaluated yawning and erection response to apomorphine treatment and then the animals were sacrificed. ET-1, eNOS, iNOS, tumour necrosis factor (TNF)-α, ET-RA and ET-RB mRNA expressions were analysed in cavernosal tissue. It was observed that yawning and erection response decreased in the diabetic group; however, both of these improved with BOS treatment. While ET-1, TNF-α and iNOS gene expressions increased, eNOS, ET-RA and ET-RB gene expressions decreased in the DM group compared to the healthy group. DM has a negative impact on cavernosal tissue blood flow through activating vasoconstrictor mediators in cavernosal tissue. BOS regulates significantly eNOS, iNOS and TNF-α expressions in a dose-dependent manner.

Assessing satisfaction in men with premature ejaculation after dapoxetine treatment in real-world practice

INTRODUCTION

There are limited data on the treatment satisfaction with dapoxetine in patients with premature ejaculation (PE).

AIMS

We aimed to evaluate the treatment satisfaction, effectiveness and safety of dapoxetine for PE patients.

METHODS

Subjects received dapoxetine (30 mg or 60 mg) alone or in combination with a phosphodiesterase type 5 inhibitor, if concurrent with erectile dysfunction for more than 4 weeks in clinical practice. Main outcome measures include Clinical Global Impression of Change (CGIC) and Clinical Global Impression of Satisfaction (CGIS).

RESULTS

From March 2014 to January 2015, a total of 286 PE patients received dapoxetine treatment in this study, with 137 (47.9%) patients diagnosed with lifelong PE and 149 (52.1%) patients diagnosed with acquired PE. At the final follow-up visit, the mean intravaginal ejaculatory latency time (an increase of 3.4 min) and mean score of Premature Ejaculation Diagnostic Tool (a decrease of -5.0) improved significantly from baseline, and the satisfaction rate and response rate to dapoxetine treatment were 45.0% and 74.6%, respectively. Satisfaction with dapoxetine treatment was highly correlated with treatment response, and might be improved by scheduled follow-up visits and escalation to a higher dose. Subjects with diabetes mellitus (DM) reported a lower treatment response than those without DM. Treatment-emergent adverse event (TEAEs) occurred in 47.7% of patients, but no serious TEAEs were reported.

CONCLUSION

Our real-world data highlight the effectiveness of dapoxetine and the importance of follow-up visits for the treatment of PE. Half of PE patients were not satisfied with dapoxetine treatment, which reflects an unmet need of present approach or an unrealistic expectation from PE patients.

Role of Caffeine Intake on Erectile Dysfunction in US Men: Results from NHANES 2001-2004

Objectives

Caffeine is consumed by more than 85% of adults and little is known about its role on erectile dysfunction (ED) in population-based studies. We investigated the association of caffeine intake and caffeinated beverages with ED, and whether these associations vary among comorbidities for ED.

Material and Method

Data were analyzed for 3724 men (≥20 years old) who participated in the National Health and Nutrition Examination Survey (NHANES). ED was assessed by a single question during a self-paced, computer-assisted self-interview. We analyzed 24-h dietary recall data to estimate caffeine intake (mg/day). Multivariable logistic regression analyses using appropriate sampling weights were conducted.

Results

We found that men in the 3^rd (85-170 mg/day) and 4^th (171-303 mg/day) quintiles of caffeine intake were less likely to report ED compared to men in the lowest 1^st quintile (0-7 mg/day) [OR: 0.58; 95% CI, 0.37–0.89; and OR: 0.61; 95% CI, 0.38–0.97, respectively], but no evidence for a trend. Similarly, among overweight/obese and hypertensive men, there was an inverse association between higher quintiles of caffeine intake and ED compared to men in the lowest 1^st quintile, P≤0.05 for each quintile. However, only among men without diabetes we found a similar inverse association (P_trend = 0.01).

Conclusion

Caffeine intake reduced the odds of prevalent ED, especially an intake equivalent to approximately 2-3 daily cups of coffee (170-375 mg/day). This reduction was also observed among overweight/obese and hypertensive, but not among diabetic men. Yet, these associations are warranted to be investigated in prospective studies.

Beneficial effect of the soluble guanylyl cyclase stimulator BAY 41-2272 on impaired penile erection in db/db-/- type II diabetic and obese mice

Type 2 diabetes mellitus (DM2) and obesity are major risk factors for erectile dysfunction (ED). In diabetes, increased oxidative stress leads to decreased nitric oxide (NO) bioavailability, and diabetic patients appear to be less responsive to conventional therapy with phosphodiesterase type 5 inhibitors. We investigated whether the soluble guanylyl cyclase stimulator BAY 41-2272 (5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridine-3-yl]pyrimidin-4ylamine) is effective in improving impaired corpus cavernosum (CC) relaxation in obese DM2 mice by reducing oxidative stress. Adult db/db(-/-) mice or their lean db(/+) littermates were used to assess vascular function, cGMP levels, antioxidant status, NADPH oxidase expression, and superoxide formation in the absence or presence of BAY 41-2272. Results showed that BAY 41-2272 (10(-8) to 10(-5) M) potently relaxed CC from db(/+) or db/db(-/-) mice in a similar manner. BAY 41-2272 significantly enhanced both endothelium-dependent and nitrergic relaxation induced by electrical field stimulation (EFS), and improved the impaired relaxation to acetylcholine and EFS in the diabetic animals in a concentration-dependent manner (10(-8) to 10(-7) M). BAY 41-2272 increased cGMP levels and potentiated relaxation responses to exogenous NO in CC. Total antioxidant status was reduced in plasma and urine whereas expression of vascular NADPH oxidase subunits (gp91phox, p22phox, and p47phox) was increased in the CC of db/db(-/-) mice, suggesting a state of oxidative stress. These effects were prevented by BAY 41-2272 in a concentration-dependent manner. These results suggest that BAY 41-2272 improves CC relaxation in db/db(-/-) mice by increasing cGMP and augmenting antioxidant status, making this drug is a potential novel candidate to treat ED.

Stem cell treatment of erectile dysfunction

Erectile Dysfunction (ED) is a common disease that typically affects older men. While oral type-5 phosphodieserase inhibitors (PDE5Is) represent a successful first-line therapy, many patients do not respond to this treatment leading researchers to look for alternative treatment modalities. Stem cell (SC) therapy is a promising new frontier for the treatment of those patients and many studies demonstrated its therapeutic effects. In this article, using a Medline database search of all relevant articles, we present a summary of the scientific principles behind SCs and their use for treatment of ED. We discuss specifically the different types of SCs used in ED, the methods of delivery tested, and the methods attempted to enhance SC therapy effect. In addition, we review the current preclinical literature on SC therapy for ED and present a summary of its findings in addition to the single clinical trial published.

How to treat erectile dysfunction in men with diabetes: from pathophysiology to treatment

Erectile dysfunction (ED) is highly prevalent affecting at least 50 % of men with diabetes mellitus (DM). DM may cause ED through a number of pathophysiological pathways. These include neuropathy, endothelial dysfunction, cavernosal smooth muscle structural/functional changes, and hormonal changes. Lifestyle changes, diabetes control, and treatment of hypogonadism are important as the first step in ED management since there is no curative treatment for ED. Phosphodiesterase type 5 inhibitors (PDE5i) are the first-line treatment option. Intracavernous administration of vasoactive drugs is commonly used as a second-line medical treatment when PDE5i have failed. Alprostadil is the most widely used drug in this second-line setting. The combination of papaverine, phentolamine, and alprostadil represents the most efficacious intracavernous pharmacologic treatment option that may save non-responders to alprostadil. Penile prosthesis implantation can be considered in treatment refractory cases, with excellent functional and safety results in the properly informed patients.

Reproductive sequelae of diabetes in male patients

Diabetes mellitus (DM) is an increasingly prevalent public health concern. A recent study projected the number of people worldwide with DM to increase from 171 million in 2000 to 366 million in 2030. Although DM is a systemic disease that often leads to end-organ dysfunction of multiple body systems, the effects of the condition on male fertility are often not fully appreciated. DM is associated with multiple risk factors for reduced male fertility potential, including erectile dysfunction, various manifestations of ejaculatory dysfunction, and hypogonadism.

A study of the early changes of the level of calcitonin gene-related Peptide and histopathology of penises of rats with experimentally induced type I diabetes mellitus by streptozocin

Introduction

Diabetes mellitus (DM) is a multiorgan disease that leads to neurovascular complications that disturb the normal erectile function.

Aim

The aim of the current work was to study the early changes occurring in the level of calcitonin gene-related peptide (CGRP) and histopathological changes in penile tissues of uncontrolled diabetic rats.

Materials and Methods

This study was carried on 50 adult male Sprague-Dawley rats divided into two main groups: group I (control, n = 10) and group II (diabetic, n = 40). Type I DM was induced by a single intraperitoneal injection of streptozotocin (60 mg/kg). The tissue level of CGRP and histopathological examination of rat penises were assessed at 2, 4, 6, and 8 weeks after induction of DM.

Results

CGRP was higher in the diabetic group at 4, 6, and 8 weeks than in the control group. However, endothelial changes and decreased smooth muscles mass started only 2 weeks after induction of DM.

Conclusion

Deterioration of histopathological features of the uncontrolled diabetic rats corporeal tissues is time dependent. Furthermore, vascular changes seem to precede the neurological changes. El-Kamshoushi AAM, Abdallah WI, Helal SF, El Azhary NM, and Hassan EM. A study of the early changes of the level of calcitonin gene-related peptide and histopathology of penises of rats with experimentally induced type I diabetes mellitus by streptozocin. Sex Med 2013;1:21–29.

Resveratrol, an activator of SIRT1, restores erectile function in streptozotocin-induced diabetic rats

The high incidence of erectile dysfunction (ED) in diabetes highlights a need for effective treatment strategies. Resveratrol, an activator of silent information regulator 2-related enzymes 1 (sirtuin1, SIRT1), has received attention for its valuable effects in cancer, neurodegenerative diseases, longevity and cardiovascular disease. To explore the effects of resveratrol in diabetes-induced ED, resveratrol was administered to rats with streptozocin (65 mg kg(-1))-induced diabetes. Erectile function, cavernous structure, tissue protein expression of silent information regulator 2-related enzymes 1 (sirtuin1, SIRT1), p53 and forkhead transcription factor O 3a (FOXO3a), superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels in the corpora cavernosa were studied. We found that SIRT1 was expressed in cavernosal tissue, and it was downregulated in the corpora of diabetic rats. The administration of resveratrol upregulated the expression of SIRT1 and restored erectile function. In contrast, resveratrol downregulated the expression of p53 and FOXO3a, which regulate apoptosis and oxidative stress. Furthermore, the resveratrol-treated group showed an improvement in smooth muscle content, SOD activity and MDA levels when compared with the diabetic group. Therefore, the ability of resveratrol to improve diabetes-induced ED is likely related to its activation of SIRT1 expression, thus causing the suppression of apoptosis and resistance towards oxidative stress.

Effects of Korean ginseng berry extract (GB0710) on penile erection: evidence from in vitro and in vivo studies

Several reports have promoted the root-derived Korean red ginseng (KRG; Panax ginseng) as alternative treatment for erectile dysfunction (ED), and ginsenosides are known to be the principal active ingredients of ginseng. Recent studies showed that ginseng berries produce more ginsenosides than KRG; thus, we investigated the ability of the Korean ginseng berry extract GB0710 to relax the penile corpus cavernosum smooth muscle (CCSM) in this study. As a comparative control, the results were compared to those obtained using KRG. In addition, possible mechanisms of action for GB0710 were investigated. While KRG and GB0710 both displayed dose-dependent relaxation effects on precontracted rabbit CCSM in vitro, GB0710 was shown to be more potent than KRG. The GB0710-induced relaxation could be partially reduced by removing the endothelium. In addition, pre-treatment with several nitric oxide (NO) inhibitors significantly inhibited the relaxation of muscle strips. Furthermore, administration of GB0710 increased intracavernosal pressure (ICP) in a rat in vivo model in both a dose- and duration-dependent manner. Intracellular NO production in human microvascular endothelial cells could be induced by GB0710 and inhibited by N(G)-monomethyl-L-arginine. In conclusion, GB0710 had a greater relaxation effect on rabbit CCSM than did KRG extract, and increased ICP in a rat model in both a dose- and a duration-dependent manner. This relaxing effect might be mediated by NO production.

Short hairpin ribonucleic acid constructs targeting insulin-like growth factor binding protein-3 ameliorates diabetes mellitus-related erectile dysfunction in rats

OBJECTIVE

To investigate the expression of insulin-like growth factor binding protein-3 (IGFBP-3) in penile cavernous of streptozotocin (STZ)-induced DM rats and whether downregulation of IGFBP-3 by intracavernosal injection of short hairpin ribonucleic acid (shRNA) targeting IGFBP-3 could improve the erectile function in DM rats.

MATERIALS AND METHODS

Diabetes was induced in rats by intraperitoneal injection of STZ, and the expression of IGFBP-3 in the penile tissue of adult normal and DM male rats was assayed using reverse transcriptase-polymerase chain reaction and Western blot. Next, shRNA-targeting IGFBP-3 and a scramble sequence were injected into the penile corpora cavernosa of DM rats. At 12 weeks after shRNA-IGFBP-3 administration, the intracavernous pressure in response to electrical stimulation of the cavernous nerves was evaluated. The expression of IGFBP-3 was assayed by Western blot. The concentration of cyclic guanosine monophosphate in the corpus cavernosum was assayed by enzyme-linked immunosorbent assay.

RESULTS

At 12 week after intraperitoneal administration of STZ, IGFBP-3 expression had increased in the penis of the DM rat (P <.05) compared with that of the normal control rats. Among the DM rats, IGFBP-3 expression at the messenger RNA and protein level was significantly inhibited 12 weeks after intracavernous administration of IGFBP-3 shRNA (P <.01). At 12 weeks after shRNA-IGFBP-3 injection, intracavernosal pressure was significantly increased in response to cavernous nerve stimulation (P <.05), and an increase in the concentration of cyclic guanosine monophosphate in the corpus cavernous tissue (P <.01) was detected compared with the "randomer" shRNA treatment group.

CONCLUSION

Gene transfer of shRNA-IGFBP-3 could improve erectile function in STZ-induced DM rats by an increase in the cyclic guanosine monophosphate concentration in cavernous tissue.

Panax notoginseng saponins improve the erectile dysfunction in diabetic rats by protecting the endothelial function of the penile corpus cavernosum

Diabetes mellitus (DM)-associated ED is predominantly due to neurovascular dysfunction mediated by nitric oxide (NO) suppression. Panax notoginseng saponins (PNS) are widely used for treating cardiovascular disease in China. The aim of this study was to evaluate the effects of PNS on penile erection and corpus cavernosum tissues in rats with diabetes-associated ED. Four weeks after PNS treatment, erectile function was assessed by intracavernous pressure (ICP) and mean arterial pressure (MAP) measurements. The level of NO, cyclic guanosine monophosphate (cGMP) and advanced glycation end products (AGEs) in cavernous tissue were assessed. Immunohistochemical staining and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) were performed for detecting endothelial NO synthase (eNOS) and apoptosis, respectively. The results show that ICP/MAP ratio was significantly increased in high-dose (150 mg kg(-1) per day) PNS-treated group compared with the diabetic ED untreated group (DM group). Compared with the untreated group, the expression of eNOS and the levels of NO and cGMP were increased in the PNS-treated groups. Moreover, apoptosis was markedly decreased in the group that received 150 mg kg(-1) per day of PNS. These results suggest that PNS may be used for improving the ED in diabetic rats via the NO/cGMP pathway and restores the function of endothelium in corpus cavernosum.

The resurgence of the vacuum erection device (VED) for treatment of erectile dysfunction

INTRODUCTION

Vacuum erection devices (VEDs) have been approved in the United States since 1982 and offer a viable alternative to oral phosphodiesterase type 5 inhibitors (PDE5i), injections and transurethral suppositories. Studies have demonstrated efficacy in erectile dysfunction (ED) associated with a variety of conditions. More recently, this modality has been evaluated in initial phosphodiesterase inhibitor nonresponders as well as for post-prostatectomy penile rehabilitation.

AIM

This article provides a detailed overview of the history of VEDs, a review of the literature, and a concise description of their new applications in modern urological practice.

METHODS

A retrospective review of publications relevant to the field of VEDs.

MAIN OUTCOME MEASURES

Review of the historical milestones, evolution, and modern utilization of VEDs in modern urological protocols.

RESULTS

Studies have demonstrated efficacy in ED associated with a variety of conditions. Early penile rehabilitation after surgery for prostate cancer with the VED appears to improve erectile function and penile length. Adverse events are transient and not serious.

CONCLUSIONS

The VED has continued to show efficacy for treatment of ED due to various etiologies and should be considered an attractive second-line therapy. In select cases such post-prostatectomy penile rehabilitation, as well as in men who cannot use a PDE5i, the vacuum device should be considered first-line treatment.

Avanafil for the treatment of erectile dysfunction: a multicenter, randomized, double-blind study in men with diabetes mellitus

OBJECTIVE

To prospectively assess the safety and effectiveness of the investigational phosphodiesterase 5 inhibitor avanafil to treat erectile dysfunction in men with diabetes mellitus.

PATIENTS AND METHODS

This 12-week, multicenter, double-blind, placebo-controlled study conducted between December 15, 2008, and February 11, 2010, randomized 390 men with diabetes and erectile dysfunction 1:1:1 to receive avanafil, 100 mg (n=129), avanafil, 200 mg (n=131), or placebo (n=130). Coprimary end points assessed changes in the percentage of sexual attempts in which men were able to maintain an erection of sufficient duration to have successful intercourse (Sexual Encounter Profile [SEP] 3), percentage of sexual attempts in which men were able to insert the penis into the partner's vagina (SEP 2), and International Index of Erectile Function erectile function domain score.

RESULTS

Compared with placebo, least-squares mean change from baseline to study end in SEP 3, SEP 2, and International Index of Erectile Function erectile function domain score were significantly improved with both avanafil, 100 mg (P≤.002), and avanafil, 200 mg (P<.001). Additional analyses indicated that successful intercourse could be initiated in 15 minutes or less through more than 6 hours after avanafil dosing. Adverse events most commonly reported with avanafil treatment were headache, nasopharyngitis, flushing, and sinus congestion.

CONCLUSION

Avanafil was safe and effective for treating erectile dysfunction in men with diabetes and was effective as early as 15 minutes and more than 6 hours after dosing. The adverse events seen with avanafil were similar to those seen with other phosphodiesterase 5 inhibitors.

TRIAL REGISTRATION

clinicaltrials.gov Identifier NCT00809471.

A review of outcomes of an intracavernosal injection therapy programme

Study Type--Therapy (outcomes research) Level of Evidence 2b. What's known on the subject? and What does the study add? Intracavernosal injection (ICI) therapy is an important treatment option for erectile dysfunction. However, high discontinuation rates have been reported for ICI therapy, and a risk of priapism has long been a concern. There has never been a large sample study performed with multivariate analysis to characterise outcomes of ICI therapy. The present paper reviews ICI therapy outcomes in a very large population of men at a tertiary care Sexual Medicine Clinic over 5 years. Multivariate analysis was used to further characterise these outcomes. The present study shows that for a large percentage of our sample of patients, ICI therapy is a successful treatment strategy. And, while discontinuation rates are still high, many of those not continuing ICI therapy achieved success with phosphodiesterase inhibitors. Also, the incidence of priapism was less in the present study than previously reported.

OBJECTIVES

• To review the outcomes, adverse events and discontinuation rates of intracavernosal injection (ICI) therapy in men with erectile dysfunction (ED) in a sexual medicine practice over a 5-year period at a tertiary referral centre. • Since 1983, ICI has become a staple therapeutic option and high success rates have been reported. However, priapism is a significant concern and discontinuation rates are estimated to be >50%.

PATIENTS AND METHODS

• Men presenting with ED who were enrolled in our ICI programme between September 2002 and August 2006 were followed at least annually. • Patient demographic information, agents used, erectile function outcomes and adverse events were recorded. • Failure was defined as the inability to have penetrative sex. Discontinuation was defined as patient declaration of such, failure to attend an annual follow-up visit or failure to call for a repeat prescription. • Multivariable analysis was used to define predictors of failure to respond to ICI therapy, as well as predictors of discontinuation within 36 months of starting ICI in those patients responding.

RESULTS

• In all, 1412 patients had complete data and constituted the study population. Most patients were using Trimix and 89% of Trimix users were capable of having sexual intercourse. • Response rates were lower in pelvic radiation and diabetic patients. • However, the discontinuation rate was significant; it was lower in men who had not undergone radical prostatectomy (RP). Of note, many RP patients discontinued ICI because of recovery of natural or phosphodiesterase type 5 inhibitor-assisted erections.

CONCLUSIONS

• ICI therapy is associated with very high success rates even in men with high comorbidity profiles; however, the discontinuation rates, even in men who had not undergone RP, by the end of the third year are significant. • Of note, the recorded priapism rate was extremely low (0.5%).

The effects of long-term administration of tadalafil on STZ-induced diabetic rats with erectile dysfunction via a local antioxidative mechanism

Type 5 phosphodiesterase inhibitors (PDE5Is) are well known being effective via the nitric oxide and cyclic guanosine monophosphate (NO-cGMP) pathway and are widely used in the treatment of diabetic erectile dysfunction (ED). However, it is unclear whether other pathways may be involved in the treatment of diabetic ED with PDE5Is. The purpose of this study was to clarify the role of antioxidants in diabetic ED treatment through the long-term administration of PDE5Is. Three groups of Sprague-Dawley rats were utilized: Group N, the normal control; Group D, streptozotocin (STZ)-induced diabetic rats as a control; and Group D+T, STZ-induced diabetic rats who received oral administration of tadalafil for 8 weeks. Erectile function was assessed by intracavernous pressure (ICP) and mean arterial pressure (MAP) during electrical stimulation of the cavernous nerve before euthanasia. The levels of malondialdehyde (MDA), superoxide dismutase (SOD) and mitochondrial membrane potential (MMP) of cavernous tissue were assessed by biochemical analysis. The morphology of mitochondria was observed by electron microscopy. The ICP/MAP ratio was higher in Group D+T than in Group D (P<0.05). The levels of MDA decreased and the activities of SOD increased in Group D+T in comparison with Group D (P<0.05). The mitochondrial membrane potential level of cavernous tissue in diabetic rats was partially recovered by tadalafil treatment for 8 weeks. The morphology changes of mitochondria were also remarkably ameliorated in Group D+T. Collectively, the long-term administration of tadalafil in diabetic rats partially reduced oxidative stress lesions of the penis via a local antioxidative stress pathway. Long-term dosages of tadalafil given once daily beginning soon after the onset of diabetes may aid in preventing rats from developing diabetic ED.

Neurotrophic effect of bone marrow mesenchymal stem cells for erectile dysfunction in diabetic rats

It has been demonstrated that intracavernous injection of bone marrow-derived mesenchymal stem cells (BM-MSCs) had beneficial effects on improving erectile function in type-1 diabetic rats. This study was designed to investigate the neurotrophic effect of BM-MSCs for type-1 diabetic rats. Streptozocin-induced type-1 diabetic rats were randomly divided into three groups: diabetic group, BM-MSCs-treated group and BM-MSCs-conditioned medium-treated group. At the 3d, 1 and 2w time points after BM-MSCs injection, three randomly selected rats in MSCs group were sacrificed and penile samples were harvested to detect BM-MSCs in penile tissue. Four weeks after intracavernous injection of BM-MSCs or BM-MSCs-conditioned medium, intracavernous pressure (ICP) was assessed to evaluate the erectile function. Immunohistochemistry was used to track labelled BM-MSCs in penile tissue and to detect neuronal nitric oxide synthase (nNOS) and neurofilament (NF) positive fibres in penile dorsal nerve. Enzyme lined immunosorbent assay (ELISA) was used to measure the concentrations of vascular endothelial growth factor (VEGF), nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in BM-MSCs-conditioned medium. BM- MSCs secreted detectable levels of VEGF, BDNF and NGF. Intracavernous injection of BM-MSCs improved erectile function in diabetic rats. The functional improvement was accompanied by promoted nNOS and NF positive nerve fibres within penile dorsal nerve in type-1 diabetic rats. Histological data revealed a time-dependent decrease in the number of BM-MSCs in the corpus cavernosum following injection. Furthermore, the beneficial effect of BM-MSCs was partially repeated by BM-MSCs-conditioned medium. Intracavernous injection of BM-MSCs is effective in improving nerve regeneration in diabetic rats. Paracrine effects of BM-MSCs are probably involved in the improvement.

Does diabetes mellitus-induced bladder remodeling affect lower urinary tract function? ICI-RS 2011

AIMS

Due to an increase in aging population and changing eating habits diabetes mellitus (DM) type II is a rapidly increasing condition worldwide. Although not so detrimental as other co-morbidities, uropathy contributes to a significantly reduced quality-of-life in those affected. The purpose of this ICS-RS report is to highlight clinical and basic research data to outline directions for further research and possible treatment approaches.

METHODS

This report is based on a think tank presentation and discussion at the ICI-RS 2011, original research data and literature research.

RESULTS

Clinical and experimental data confirm that detrusor overactivity, both neurogenic and myogenic, and changes in transmitter regulation leading to a hyper- excitability of the detrusor are the major findings in diabetic neuropathic bladders. These findings seem to be related to an earlier stage of DM, whereas detrusor underactivity appears to be linked to later stages of DM. Detrusor smooth muscle cells seem to be modulated directly by hyperglycemia. Data support the theory that hyperglycemia-induced oxidative stress in the detrusor smooth muscle and that micro- and macrovascular events are also responsible for urologic complications of DM.

CONCLUSIONS

DM causes bladder remodelling leading to uropathy in a mulitfactorial way. Future research should focus on the effects of DM as a function of time and develop novel animal models looking at defined aspects as well as interaction of different aspects- such as oxidative stress in neurogenic, myogenic and urothelial components and the role of inflammation and hypoxia caused by vascular complications.

Mobilisation of endothelial progenitor cells: one of the possible mechanisms involved in the chronic administration of melatonin preventing erectile dysfunction in diabetic rats

Diabetes-induced oxidative stress plays a critical role in the mobilisation of endothelial progenitor cells (EPCs) from the bone marrow to the circulation. This study was designed to explore the effects of chronic melatonin administration on the promotion of the mobilisation of EPCs and on the preservation of erectile function in type I diabetic rats. Melatonin was administered to streptozotocin-induced type I diabetic rats. EPCs levels were determined using flow cytometry. Oxidative stress in the bone marrow was indicated by the levels of superoxide dismutase and malondialdehyde. Erectile function was evaluated by measuring the intracavernous pressure during an electrostimulation of the cavernous nerve. The density of the endothelium and the proportions of smooth muscle and collagen in the corpus cavernosum were determined by immunohistochemistry. The administration of melatonin increased the superoxide dismutase level and decreased the malondialdehyde level in the bone marrow. This effect was accompanied by an increased level of circulating EPCs in the diabetic rats. The intracavernous pressure to mean arterial pressure ratio of the rats in the treatment group was significantly greater, compared with diabetic control rats. The histological analysis demonstrated an increase in the endothelial density of the corpus cavernosum after the administration of melatonin. However, melatonin treatment did not change the proportions of smooth muscle and collagen in the corpus cavernosum of diabetic rats. Chronic administration of melatonin has a beneficial effect on preventing erectile dysfunction (ED) in type I diabetic rats. Promoting the mobilisation of EPCs is one of the possible mechanisms involved in the improvement of ED.

Comparison of sildenafil with strontium fructose diphosphate in improving erectile dysfunction against upregulated cavernosal NADPH oxidase, protein kinase Cε, and endothelin system in diabetic rats

Objectives

Phosphodiesterase type 5 inhibitors are potent in relieving erectile dysfunction (ED), however, they are less satisfactory in diabetic patients, probably due to the pro-inflammatory biomarkers caused by diabetes. Therefore, it was interesting to compare the effects of sildenafil with strontium fructose 1,6-diphosphate (FDP-Sr) on cavernosal vascular activity and expressions of pro-inflammatory biomarkers in diabetic rats.

Methods

Male Sprague-Dawley rats were injected with streptozocin (60 mg/kg, i.p.) to develop diabetes. The animals were diabetic for eight weeks with sildenafil (12 mg/kg per day) or FDP-Sr (200 mg/kg per day) being administered for the last four of those eight weeks.

Key findings

Sildenafil was more effective in relieving reduced vascular dilatation (relevant to ED), but less in attenuating over-expressions of NADPH oxidase p22, p47 and p67 subunits, and ETA/BR (endothelin receptor type A and type B) in the diabetic cavernosum. In contrast, FDP-Sr was less effective in improving ED, but more effective in normalizing the abnormal NADPH oxidase and ETA/BR.

Conclusions

The activated NADPH oxidase and upregulated ETAR and ETBR due to diabetic lesions played a minor or moderate role in ED. By offering extra ATP, FPD-Sr suppressed these abnormalities, however, sildenafil did not. A combined therapy of sildenafil with FDP-Sr may be more effective in relieving ED in diabetic patients through normalizing pro-inflammatory cytokines and improving the nitric oxide/cGMP pathway in the cavernosum.

Erectile dysfunction and diabetes: a review of the current evidence-based medicine and a synthesis of the main available therapies

AIM

This review aimed to provide an update of the epidemiology, pathophysiology and management of erectile dysfunction (ED) in diabetes patients.

METHODS

Data on the management of ED in diabetes patients in the literature were analyzed using Medline, and by matching the following keywords: diabetes; erectile dysfunction; endothelial dysfunction; cardiovascular disease; phosphodiesterase inhibitors; intracavernous injection; and penile prosthesis.

RESULTS

ED has a higher incidence in diabetic patients. The pathophysiology is multifactorial, involving endothelial dysfunction, specific complications of diabetes and psychological factors. Recent studies have shown that ED is able to predict future cardiovascular events not only in non-diabetics, but also in patients with diabetes. ED could also be a potential marker to screen for silent coronary artery disease. The management of ED has been revolutionized by the discovery of phosphodiesterase type-5 (PDE5) inhibitors, the first-line therapeutic options for diabetic men with ED that are efficient and safe. As a second line, intracavernous injections remain a gold-standard treatment, although a vacuum device can be used as well. In cases of failure, penile prosthesis may be considered. Hypogonadism, commonly found in diabetics, may require identification and treatment. Optimalized glycaemic control, management of associated co-morbidities and lifestyle modifications are essential in all patients. As ED and diabetes negatively impact male self-esteem, and generate depression and anxiety, the psychological treatment of patients is also likely to be beneficial.

CONCLUSION

The aetiology of diabetic ED is multifactorial. Endothelial dysfunction is the link between diabetes-induced ED and coronary artery disease. A global approach is needed for the successful management of diabetic ED.