Testosterone positively regulates functional responses and nitric oxide expression in the isolated human corpus cavernosum

Polystyrene nanoplastics exposure causes erectile dysfunction in rats

Polystyrene nanoplastics (PS-NPs), emerging and increasingly pervasive environmental contaminants, have the potential to cause persistent harm to organisms. Although previous reports have documented local accumulation and adverse effects in a variety of major organs after PS-NPs exposure, the impact of PS-NPs exposure on erectile function remains unexplored. Herein, we established a rat model of oral exposure to 100 nm PS-NPs for 28 days. To determine the best dose range of PS-NPs, we designed both low-dose and high-dose PS-NPs groups, which correspond to the minimum and maximum human intake doses, respectively. The findings indicated that PS-NPs could accumulate within the corpus cavernosum and high dose but not low dose of PS-NPs triggered erectile dysfunction. Moreover, the toxicological effects of PS-NPs on erectile function include fibrosis in the corpus cavernous, endothelial dysfunction, reduction in testosterone levels, elevated oxidative stress and apoptosis. Overall, this study revealed that PS-NPs exposure can cause erectile dysfunction via multiple ways, which provided new insights into the toxicity of PS-NPs.

Androgens and erectile dysfunction: from androgen deficiency to treatment

INTRODUCTION

Androgens play important roles in regulating the growth and development of the male reproductive system and maintaining libido and erectile function. The specific mechanisms by which androgen deficiency leads to erectile dysfunction (ED) are not yet fully understood.

OBJECTIVES

To understand the mechanisms and treatment of androgen deficiency-related ED.

METHODS

A literature search in the past 10 years was conducted in PubMed and Google Scholar to determine the effects of androgen deficiency on erectile function and the treatment of androgen deficiency.

RESULTS

Androgen deficiency can be caused by hypothalamic-pituitary lesions and injuries, testicular-related diseases and injuries, endocrine and metabolic disorders, the side effects of medication, and age. Androgen deficiency can lead to ED by inhibiting the NOS/NO/cGMP pathway (nitric oxide synthase/nitric oxide/cyclic guanosine monophosphate) and altering the expression of ion channel proteins, as well as by inducing oxidative stress, death, and fibrosis in penile corpus cavernosum cells. Testosterone replacement therapy is effective at improving the serum testosterone levels and erectile function in patients with androgen deficiency. For patients who need to maintain a low androgenic state, erectile function can be improved by lifestyle changes, treatment with phosphodiesterase type 5 inhibitors, low-intensity extracorporeal shock wave therapy, and stem cell therapy.

CONCLUSIONS

Androgen deficiency can affect the structure and function of the penile corpus cavernosum, leading to ED. Areas of further study include how androgen replacement therapy can improve erectile function and how to improve the maintenance of erectile function in patients with hypoandrogenic status.

Cardiometabolic Disorder and Erectile Dysfunction

Erectile dysfunction (ED), which is defined as the inability to attain and maintain a satisfactory penile erection to sufficiently permit sexual intercourse, is a consequence and also a cause of cardiometabolic disorders like diabetes mellitus, systemic hypertension, central obesity, and dyslipidemia. Although there are mounting and convincing pieces of evidence in the literature linking ED and cardiometabolic disorders, impairment of nitric oxide-dependent vasodilatation seems to be the primary signaling pathway. Studies have also implicated the suppression of circulating testosterone, increased endothelin-1, and hyperactivation of Ang II/ATIr in the pathogenesis of ED and cardiometabolic disorders. This study provides comprehensive details of the association between cardiometabolic disorders and ED and highlights the mechanisms involved. This would open areas to be explored as therapeutic targets in the management of ED and cardiometabolic disorders. It also provides sufficient evidence establishing the need for the management of cardiometabolic disorders as an adjunct therapy in the management of ED.

Ascorbic acid attenuates gasoline-induced testicular toxicity, sperm quality deterioration, and testosterone imbalance in rats

The present study evaluated the protective effect of ascorbic acid (ASCB) against gasoline fumes (PET) induced testicular oxidative stress, sperm toxicity, and testosterone imbalance in Wistar rats. Twenty-four (24) male albino rats (75 ± 16 g) were randomized into three experimental groups (N = 8). The control group: received normal saline, PET group: exposed to PET 6 h daily by inhalation in an exposure chamber and PET + 200 mg ASCB/kg body weight group: exposed to PET 6 h daily by inhalation and administered ASCB per os. Treatment of ASCB and PET exposure was done thrice and five times weekly for a period of 10 weeks respectively. ASCB co-treatment prevented PET-induced increases in the oxidative stress markers (glutathione, glutathione S-transferase, superoxide dismutase, catalase, hydrogen peroxide generation, nitric oxide, and lipid peroxidation) and serum testosterone concentration (p < .05). Sperm quality was low and those with damaged heads and tails increased alongside histological injuries in the PET-exposed rats, which were also minimized with ASCB administration. ASCB protected against PET-induced oxidative stress, sperm, and testis damage in rats.

Long-acting glucagon-like peptide 1 receptor agonists boost erectile function in men with type 2 diabetes mellitus complaining of erectile dysfunction: A retrospective cohort study

INTRODUCTION

The pharmacological management of erectile dysfunction (ED) in type 2 diabetes (T2D) is challenging as ED has a multifactorial etiology. The therapeutic potential of certain antihyperglycemic medications, such as glucagon-like peptide 1 receptor agonists (GLP-1RAs), has yet to be entirely studied in this setting.

MATERIAL AND METHODS

A retrospective cohort study was conducted on 108 outpatients (median age 60 [56, 65] years) with T2D complaining of ED. Data were extracted from a database referring to patients with a 1-year follow-up on stable treatment with metformin alone (n = 45) and GLP-1RAs as an add-on to metformin (n = 63). Erectile function was assessed by the 5-item International Index of Erectile Function (IIEF5) at baseline and after 1 year of stable treatment . Values were compared between baseline (T0) and after 12 months of treatment (T12).

RESULTS

ED was confirmed in all at baseline, with an IIEF5 score range between 13 and 19 points. After 12 months of treatment, glucose management was better in patients treated with GLP-1RAs plus metformin (HbA1c T0: 8.3 ± 0.2 vs. HbA1c T12: 7% ± 0.3%, p < 0.0001) than in those on metformin alone (HbA1c T0: 7 ± 0.5 vs. HbA1c T12: 7.3 ± 0.4, p = 0.0007). GLP-1RAs plus metformin over metformin alone resulted in a significant weight loss (-5.82 ± 0.69 kg, p < 0.0001), reduction in waist circumference (-4.99 ± 0.6 cm, p < 0.0001), improvement in HbA1c (-0.56% ± 0.13%, p < 0.0001), and fasting plasma glucose (-25.54 ± 3.09 mg/dL, p < 0.0001), increase in total (+41.41 ± 6.11 ng/dL, p < 0.0001) and free (0.44 ± 0.09 ng/dL, p < 0.0001) testosterone levels, and gain in self-reported erectile function (IIEF5 score: +2.26 ± 0.26, p < 0.0001). The gain in the IIEF5 score was more relevant in patients with higher baseline IIEF5 score (estimated coefficient: 0.16 ± 0.08, p = 0.045), those having carotid stenosis (0.50 ± 0.24, p = 0.045), and showing weight loss from baseline (-0.08 ± 0.03, p = 0.013). The leading determinant of the final IIEF5 score was a 1-year treatment with GLP-1RAs plus metformin over metformin alone (2.74 ± 0.53, p < 0.0001).

DISCUSSION

GLP-1RAs plus metformin over metformin alone improved ED regardless of different background characteristics of patients and partially irrespective of therapeutic targets achieved after 12 months of treatment. GLP-1RAs may have induced positive vasculature effects, resulting in improved erectile function in T2D.

CONCLUSION

Due to the retrospective nature of the study, a potential cause-effect relationship between the use of GLP-1RAs plus metformin over metformin alone in improving ED cannot be verified and confirmed. Randomized clinical trials are needed to provide evidence supporting the use of GLP-1RAs for treating ED in T2D.

Princeton IV consensus guidelines: PDE5 inhibitors and cardiac health

BACKGROUND

In 1999, 1 year after the approval of the first oral phosphodiesterase type 5 (PDE5) inhibitor for the treatment of erectile dysfunction (ED), the first Princeton Consensus Conference was held to address the clinical management of men with ED who also had cardiovascular disease. These issues were readdressed in the second and third conferences. In the 13 years since the last Princeton Consensus Conference, the experience with PDE5 inhibitors is more robust, and recent new data have emerged regarding not only safety and drug-drug interactions, but also a potential cardioprotective effect of these drugs.

AIM

In March 2023, an interdisciplinary group of scientists and practitioners met for the fourth Princeton Consensus Guidelines at the Huntington Medical Research Institutes in Pasadena, California, to readdress the cardiovascular workup of men presenting with ED as well as the approach to treatment of ED in men with known cardiovascular disease.

METHOD

A series of lectures from experts in the field followed by Delphi-type discussions were developed to reach consensus.

OUTCOMES

Consensus was reached regarding a number of issues related to erectile dysfunction and the interaction with cardiovascular health and phosphodiesterase-5 inhibitors.

RESULTS

An algorithm based on recent recommendations of the American College of Cardiology and American Heart Association, including the use of computed tomography coronary artery calcium scoring, was integrated into the evaluation of men presenting with ED. Additionally, the issue of nitrate use was further considered in an algorithm regarding the treatment of ED patients with coronary artery disease. Other topics included the psychological effect of ED and the benefits of treating it; the mechanism of action of the PDE5 inhibitors; drug-drug interactions; optimizing use of a PDE5 inhibitors; rare adverse events; potential cardiovascular benefits observed in recent retrospective studies; adulteration of dietary supplements with PDE5 inhibitors; the pros and cons of over-the-counter PDE5 inhibitors; non-PDE5 inhibitor therapy for ED including restorative therapies such as stem cells, platelet-rich plasma, and shock therapy; other non-PDE5 inhibitor therapies, including injection therapy and penile prostheses; the issue of safety and effectiveness of PDE5 inhibitors in women; and recommendations for future studies in the field of sexual dysfunction and PDE5 inhibitor use were discussed.

CLINICAL IMPLICATIONS

Algorithms and tables were developed to help guide the clinician in dealing with the interaction of ED and cardiovascular risk and disease.

STRENGTHS AND LIMITATIONS

Strengths include the expertise of the participants and consensus recommendations. Limitations included that participants were from the United States only for this particular meeting.

CONCLUSION

The issue of the intersection between cardiovascular health and sexual health remains an important topic with new studies suggesting the cardiovascular safety of PDE5 inhibitors.

Withania somnifera ameliorates sexual arousal and impotence in stressed sexually sluggish male rats by modulating neurotransmitters and NO/cGMP/PDE5α pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Psychological stress is a growing global threat to male sexual potency and erection efficiency. Withania somnifera (L.) Dunal (WS), also known as Ashwagandha, is a well-known Ayurvedic herb. The roots of Withania somnifera improve the body's ability to handle stress, strengthen the immune system, promote healthy ageing, and have aphrodisiac properties with male sexual stimulation effects. Despite its widespread acceptance as an Ayurvedic stress-relieving drug with beneficial effects on male reproductive health, Withania somnifera has yet to be studied for its potential role in improving the sexual arousal and erectile dysfunction of psychologically stressed sexually sluggish males.

AIM OF THE STUDY

To investigate the therapeutic effects of purified root powder of Withania somnifera on sexual behaviour and erectile efficiency in stressed sexually sluggish male rats.

MATERIALS AND METHODS

Sexually sluggish male rats were screened by premating tests after being exposed to a psychological stressor, restraint stress, 3 h/day for 30 days. Subsequently, these rats were treated with purified root powder of WS (150 or 300 mg/kg/day-PO) or sildenafil (5 mg/kg/day-PO) for 30 days. The rats were sacrificed after 24 h of the last treatment, and the effects on various factors related to sexual behaviour, penile histomorphology, serum hormones, and neurotransmitters associated with sexual arousal and penile erection were examined.

RESULTS

WS treatment improves prosexual and sexual behaviour in psychologically stressed sexually sluggish male rats by increasing non-contact erections and mounts, intromission, and ejaculation frequencies, while decreasing sexual exhaustion by decreasing post-ejaculation intervals and latencies. WS also modulates neurotransmitters and hormones associated with sexual desire and stress, including dopamine, serotonin, corticosterone, and prolactin. Additionally, there was also a dose-dependent increase in serum LH, FSH, and testosterone levels. The administration of WS to sexually sluggish rats resulted in significant improvements in penile histomorphology, specifically by increasing the ratio of smooth muscle (SM) to collagen. Furthermore, in sexually sluggish rats, WS treatment increased the expression of markers associated with penile erection facilitation, such as nNOS, eNOS, p-Akt, nitric oxide, acetylcholine, and cGMP. Notably, WS treatment decreased the expression of penile PDE5α in these rats in a dose-dependent manner. Remarkably, the therapeutic effects of WS are comparable to those of sildenafil.

CONCLUSIONS

Purified root powder of Withania somnifera was found to improve sexual arousal and erection efficiency in stressed, sexually sluggish male rats. This improvement was achieved by modulating the HPG and HPA axes as well as the NO/cGMP/PDE5α pathway involved in penile erection. Thus, our findings strongly support the potent therapeutic potential of purified root powder of WS in improving the sexual health of stressed sexually sluggish rats.

Understanding human aging and the fundamental cell signaling link in age-related diseases: the middle-aging hypovascularity hypoxia hypothesis

Aging-related hypoxia, oxidative stress, and inflammation pathophysiology are closely associated with human age-related carcinogenesis and chronic diseases. However, the connection between hypoxia and hormonal cell signaling pathways is unclear, but such human age-related comorbid diseases do coincide with the middle-aging period of declining sex hormonal signaling. This scoping review evaluates the relevant interdisciplinary evidence to assess the systems biology of function, regulation, and homeostasis in order to discern and decipher the etiology of the connection between hypoxia and hormonal signaling in human age-related comorbid diseases. The hypothesis charts the accumulating evidence to support the development of a hypoxic milieu and oxidative stress-inflammation pathophysiology in middle-aged individuals, as well as the induction of amyloidosis, autophagy, and epithelial-to-mesenchymal transition in aging-related degeneration. Taken together, this new approach and strategy can provide the clarity of concepts and patterns to determine the causes of declining vascularity hemodynamics (blood flow) and physiological oxygenation perfusion (oxygen bioavailability) in relation to oxygen homeostasis and vascularity that cause hypoxia (hypovascularity hypoxia). The middle-aging hypovascularity hypoxia hypothesis could provide the mechanistic interface connecting the endocrine, nitric oxide, and oxygen homeostasis signaling that is closely linked to the progressive conditions of degenerative hypertrophy, atrophy, fibrosis, and neoplasm. An in-depth understanding of these intrinsic biological processes of the developing middle-aged hypoxia could provide potential new strategies for time-dependent therapies in maintaining healthspan for healthy lifestyle aging, medical cost savings, and health system sustainability.

Sex-specific effects of daily tadalafil on diabetic heart kinetics in RECOGITO, a randomized, double-blind, placebo-controlled trial

Cyclic GMP-phosphodiesterase type 5 (PDE5) inhibition has been shown to counteract maladaptive cardiac changes triggered by diabetes in some but not all studies. We performed a single-center, 20-week, double-blind, randomized, placebo-controlled trial (NCT01803828) to assess sex differences in cardiac remodeling after PDE5 inhibition in patients with diabetic cardiomyopathy. A total of 122 men and women (45 to 80 years) with long-duration (>3 years) and well-controlled type 2 diabetes mellitus (T2DM; HbA1c < 86 mmol/mol) were selected according to echocardiographic signs of cardiac remodeling. Patients were randomly assigned (1:1) to placebo or oral tadalafil (20 mg, once daily). The primary outcome was to evaluate sex differences in cardiac torsion change. Secondary outcomes were changes in cardiovascular, metabolic, immune, and renal function. At 20 weeks, the treatment-by-sex interaction documented an improvement in cardiac torsion (-3.40°, -5.96; -0.84, P = 0.011) and fiber shortening (-1.19%, -2.24; -0.14, P = 0.027) in men but not women. The primary outcome could not be explained by differences in cGMP concentrations or tadalafil pharmacodynamics. In both sexes, tadalafil improved hsa-miR-199-5p expression, biomarkers of cardiovascular remodeling, albuminuria, renal artery resistive index, and circulating Klotho concentrations. Immune cell profiling revealed an improvement in low-grade chronic inflammation: Classic CD14⁺⁺CD16^- monocytes reduced, and Tie2⁺ monocytes increased. Nine patients (14.5%) had minor adverse reactions after tadalafil administration. Continuous PDE5 inhibition could offer a strategy to target cardiorenal complications of T2DM, with sex- and tissue-specific responses. Further studies are needed to confirm Klotho and hsa-miR-199-5p as markers for T2DM complications.

Androgenic steroids dysregulation and the risk of coronary artery disease

INTRODUCTION

Endogenous testosterone deficiency or excess anabolic-androgenic steroids (AAS) have been linked to alter the physiology of different organs in the body, more specifically, the vasculature of coronary arteries. Despite the health-related concerns of using synthetic testosterone derivatives, such as AAS, there has been a tremendous increase in the use of AAS among athletes and bodybuilders.

AREAS COVERED

We have highlighted the three main mechanisms that AAS increase the risk of coronary artery disease (CAD): altering the homeostasis of lipid metabolism which results in dyslipidemia and subsequently atherosclerosis, disturbing the function of platelet which results in platelet aggregation and subsequent thrombosis, and increasing the risk of coronary vasospasm by affecting the physiological function of vascular bed.

EXPERT OPINION

Despite the restriction of AAS in specific clinical conditions such as testosterone deficiency and cancer therapy, many amateurs' athletes misuse the AAS. Although there has been a strong association between the AAS misuse and risk of developing CAD, the more valued approach would be a randomized clinical double-blind trial. The suggested primary endpoint would be an occurrence of adverse cardiovascular events, such as myocardial infarction, cerebrovascular accidents, and death. Increasing awareness of the risk of missing AAS among high-risk groups is imperative.

Cardiovascular/Stroke Risk Assessment in Patients with Erectile Dysfunction-A Role of Carotid Wall Arterial Imaging and Plaque Tissue Characterization Using Artificial Intelligence Paradigm: A Narrative Review

PURPOSE

The role of erectile dysfunction (ED) has recently shown an association with the risk of stroke and coronary heart disease (CHD) via the atherosclerotic pathway. Cardiovascular disease (CVD)/stroke risk has been widely understood with the help of carotid artery disease (CTAD), a surrogate biomarker for CHD. The proposed study emphasizes artificial intelligence-based frameworks such as machine learning (ML) and deep learning (DL) that can accurately predict the severity of CVD/stroke risk using carotid wall arterial imaging in ED patients.

METHODS

Using the PRISMA model, 231 of the best studies were selected. The proposed study mainly consists of two components: (i) the pathophysiology of ED and its link with coronary artery disease (COAD) and CHD in the ED framework and (ii) the ultrasonic-image morphological changes in the carotid arterial walls by quantifying the wall parameters and the characterization of the wall tissue by adapting the ML/DL-based methods, both for the prediction of the severity of CVD risk. The proposed study analyzes the hypothesis that ML/DL can lead to an accurate and early diagnosis of the CVD/stroke risk in ED patients. Our finding suggests that the routine ED patient practice can be amended for ML/DL-based CVD/stroke risk assessment using carotid wall arterial imaging leading to fast, reliable, and accurate CVD/stroke risk stratification.

SUMMARY

We conclude that ML and DL methods are very powerful tools for the characterization of CVD/stroke in patients with varying ED conditions. We anticipate a rapid growth of these tools for early and better CVD/stroke risk management in ED patients.

Priming metabolism with the type 5 phosphodiesterase: the role of cGMP-hydrolyzing enzymes

The cyclic guanosine monophosphate (cGMP) signaling system is one of the most prominent regulators of many physiopathological processes in humans and rodents. It has been strongly established as an accomplished cellular signal involved in the regulation of energy homeostasis and cell metabolism, and pharmacological enhancement of cGMP has shown beneficial effects in metabolic disorders models. cGMP intracellular levels are finely regulated by phosphodiesterases (PDEs). The main enzyme responsible for the degradation of cGMP is PDE5. Preclinical and clinical studies have shown that PDE5 inhibitors (PDE5i) have beneficial effects on improving insulin resistance and glucose metabolism representing a promising therapeutic strategy for the treatment of metabolic disorders. This review aims to describe the molecular basis underlying the use of PDE5i to prompt cell metabolism and summarize current clinical trials assessing the effects of PDE5i on glucose metabolism.

The Etiology and Pathophysiology Genesis of Benign Prostatic Hyperplasia and Prostate Cancer: A New Perspective

Background: The etiology of benign prostatic hyperplasia and prostate cancer are unknown, with ageing being the greatness risk factor. Methods: This new perspective evaluates the available interdisciplinary evidence regarding prostate ageing in terms of the cell biology of regulation and homeostasis, which could explain the timeline of evolutionary cancer biology as degenerative, inflammatory and neoplasm progressions in these multifactorial and heterogeneous prostatic diseases. Results: This prostate ageing degeneration hypothesis encompasses the testosterone-vascular-inflamm-ageing triad, along with the cell biology regulation of amyloidosis and autophagy within an evolutionary tumorigenesis microenvironment. Conclusions: An understanding of these biological processes of prostate ageing can provide potential strategies for early prevention and could contribute to maintaining quality of life for the ageing individual along with substantial medical cost savings.

Effects of androgen on extracellular vesicles from endothelial cells in rat penile corpus cavernosum

BACKGROUND

The explicit mechanism of erectile dysfunction caused by low androgen status is unknown. It was reported that eNOS was expressed in extracellular vesicles (EVs). Androgen may regulate erectile function by affect the release of EVs from endothelial cells.

OBJECTIVES

To investigate whether androgen affects the production of EVs and nitric oxide (NO) in endothelial cells of rat penile corpus cavernosum.

MATERIALS AND METHODS

Endothelial cells of rat penile corpus cavernosum were isolated and purified from 6-week-old healthy male Sprague Dawley (SD) rats. Endothelial cells were treated with different concentrations of dihydrotestosterone (DHT) in a cell culture medium as follows: no-androgen group (NA group, DHT 0 nmol/L), very-low androgen group (VLA group, DHT 0.1 nmol/L), low androgen group (LA group, DHT 1 nmol/L), and physiological concentrations androgen group (PA group, DHT 10 nmol/L). After 24 h, EVs of supernatant in each group were isolated and identified. The content of EVs and NO in the supernatant and the expression of CD9, CD63, TSG101, and eNOS in EVs were detected.

RESULTS

Positive expression of CD9, CD63, TSG101, and eNOS was found in isolated EVs. The concentration of EVs was lower in the NA group compared with other groups (p < 0.01). The expression of eNOS and the concentration of NO was lower in the NA group than that in other groups (p < 0.05); it was lower in the VLA group than that in the LA group (p < 0.05) and lower in LA group than that in PA group (p < 0.05). When the concentration of DHT in endothelial cell culture medium ranged from 0 to 10 nmol/L, the concentration of DHT was positively correlated with the content of EVs and NO.

CONCLUSION

Decrease in eNOS-expressing EVs is one mechanism of NO reduction in endothelial cells of rat corpus cavernosum caused by low androgen levels.