Physiology and Pharmacology of Ejaculation

Leptin action on ARC-PVN neural circuit regulates ejaculation behavior by altering sympathetic neuroplasticity

BACKGROUND

Although some studies have revealed the close relationship between leptin and premature ejaculation in clinical practice, whether and how leptin participates in the regulation of ejaculatory behaviors are still unknown.

OBJECTIVE

To explore the role of leptin on ejaculatory behaviors and its underlying mechanism.

MATERIALS AND METHODS

Copulation behavior tests were performed after acute and chronic leptin administration at peripheral and central levels. To compare changes in sympathetic nervous system activity, lumbar sympathetic nervous activity, serum noradrenaline levels, and the distribution of sympathetic fibers in vas deferens and seminal vesicles were analyzed. Construction of virus vector, immunohistochemistry, and optogenetics techniques were used to explore the neural circuit mechanism. The density of dendritic spines in parvocellular region of paraventricular nucleus was measured by Golgi staining.

RESULTS

Acute administration of leptin had no effect on ejaculation behavior in male mice. However, both mount latency and ejaculation latency were significantly shortened, even if serum leptin decreased to normal level, after chronic administration of leptin at peripheral or central level. Additionally, sympathetic fibers in vas deferens and seminal vesicles obviously increased, in which arcuate nucleus‒paraventricular nucleus circuit and glutamatergic neurons in paraventricular nucleus played an important role. Dendritic spine density in parvocellular region increased after chronic leptin administration.

DISCUSSION AND CONCLUSION

The role of leptin in regulating ejaculation behavior was chronic, not acute, in which leptin chronically modulated sympathetic neuroplasticity via arcuate nucleus‒paraventricular nucleus circuit and glutamatergic neurons in paraventricular nucleus and promoted ejaculatory behaviors. Increased dendritic spine density in parvocellular region of paraventricular nucleus may be involved as well.

Spinal cord epidural stimulation for male sexual function in spinal cord injured rats

BACKGROUND

95% of men with spinal cord injuries exhibit difficulties with sexual function, including erectile dysfunction, anejaculation, retrograde ejaculation, poor ejaculatory force, and poor sperm quality.

AIM

The primary goal is to determine if well-established interventions, such as spinal cord epidural stimulation, are a feasible treatment for sexual dysfunction and if locomotor recovery training can be used to improve ejaculatory function in a rodent model of spinal cord injury (SCI).

METHODS

Male Wistar rats underwent thoracic laminectomies (shams), spinal cord transections, or moderate spinal cord contusion injuries. In urethane-anesthetized rodents, terminal spinal cord epidural stimulation was performed to target the mid-lumbar level spinal generator for ejaculation (SGE) in animals with transection spinal cord injuries at 3-, 14-, or 70-days post-injury and in animals with sham surgeries and spinal cord contusions at 70 days post-injury. The impact of locomotor training frequency was examined in two groups of rats with spinal cord contusion, which underwent 1-hr of assisted plantar stepping on a treadmill, training two or five times weekly for 6 weeks. Terminal experiments in all groups were followed by measures of sperm concentration and post-mortem testicular weight and morphology.

OUTCOMES

Spinal cord epidural stimulation consistently induced the expulsion phase of ejaculation, and occasionally the emission phase of ejaculation in rats with chronic SCI.

RESULTS

All animals were most responsive to spinal cord epidural stimulation combined with manual stimulation to induce ejaculation, with chronic injury resulting in the most consistent responses. Locomotor training improved response rates to spinal cord epidural stimulation, with intermittent training resulting in the most consistent induction of both the emission and expulsion phases of ejaculation. Sperm concentration was impacted by injury completeness and time-post injury, which was lowest in the chronic complete transection group of rats. Locomotor training resulted in an overall increase in sperm concentration, with 2 days per week of training resulting in a significant improvement of sperm motility.

CLINICAL IMPLICATIONS

Spinal cord epidural stimulation combined with locomotor training is a feasible intervention for individuals with SCI who seek to regain sexual function.

STRENGTHS AND LIMITATIONS

Although we have anecdotal reports of non-targeted L3 spinal cord epidural stimulation inducing ejaculation in humans having spinal cord injuries, the current outcomes may be underestimated as stimulation was carried out in anesthetized animals.

CONCLUSION

Spinal cord epidural stimulation to target the SGE is a feasible intervention for sexual dysfunction following SCI.

The role of acupuncture in treating premature ejaculation and its probable neurobiological mechanism

BACKGROUND

Premature ejaculation (PE) is one of the most common diseases in andrology and leads to serious male sexual dysfunction. Although several targeted oral drug therapies are used to treat PE, they often face challenges related to imprecise targeting and adverse effects. Acupuncture has shown potential in prolonging ejaculation time and improving couples' sexual quality of life. This review aims to summarize the benefits of acupuncture in treating PE and explore its probable neurobiological mechanisms.

RESULTS

The review included eight clinical trials involving 679 patients, of which 294 were treated with acupuncture. Furthermore, this review analyzed acupuncture points, needle retention time, treatment duration, and their probable neurobiological mechanisms. The proposed mechanisms include stimulating the frontal functional lobe, inhibiting spinal cord neural pathways, regulating serotonin levels, enhancing 5-hydroxytryptamine receptor IB excitability, reducing penile sensitivity, and modulating hormone levels.

CONCLUSIONS

Acupuncture is a viable alternative or complementary therapy for PE, and neurobiological mechanisms appear to play a key role, but further experimental validation is needed.

Recuperación de espermatozoides de la orina en hombres con eyaculación retrógrada

Introducción

La eyaculación retrógrada (ER) es la ausencia total o parcial de emisión del esperma, con la consecuente derivación del semen hacia la vejiga durante la fase de emisión de la eyaculación. Existe un grupo de pacientes en los que la evaluación del eyaculado no es suficiente para su detección. Y, en ocasiones, va a ser necesario recurrir a la utilización de métodos invasivos como la extracción de fluido epididimario, o la biopsia testicular para tratar su infertilidad.

Contenido

El documento define la ER, y los métodos para su diagnóstico. También aborda la detección de espermatozoides en la orina poseyaculado (OPE), la preparación y recuperación de espermatozoides de la orina, y su uso posterior en técnicas de reproducción asistida.

Resumen

El diagnóstico de ER se basa en la detección de espermatozoides en OPE en pacientes con aspermia o con oligozoospermia y volumen seminal bajo o normal. Aunque la presencia de espermatozoides en OPE podría considerarse por sí misma diagnóstica de ER, existe una falta de consenso en cuanto a definir exactamente los criterios diagnósticos y son muy pocos los estudios que los describen. Un correcto diagnóstico de la ER permite utilizar OPE para la obtención de espermatozoides y su posterior uso en técnicas de reproducción humana asistida, evitando técnicas invasivas.

Perspectivas

Un importante número de pacientes con ER puede permanecer sin diagnosticar. Por ello, es fundamental realizar el estudio de ER en pacientes con sospecha, mediante el estudio de la OPE, siendo necesaria una adecuada interpretación de los resultados para su correcto diagnóstico.

The value of 5-HT, leptin, and NE in the classification of premature ejaculation

Background

While premature ejaculation (PE) can be divided into lifelong PE (LPE), acquired PE, natural variable PE (NPE), and subjective PE (SPE), there is no objective method to classify PE.

Aim

To determine the value of serum serotonin (5-HT), leptin, and norepinephrine (NE) levels in the classification of PE.

Methods

From July 2023 to July 2024, we recruited 150 participants and divided them into 4 groups: LPE (43 cases), NPE (32 cases), SPE (35 cases), and non-PE (40 cases) groups. All participants' baseline data, premature ejaculation diagnostic tool score, and intravaginal ejaculation latency time were investigated. In addition, all participants' serum 5-HT, leptin, and NE levels were measured.

Outcome

Serum 5-HT, NE, and leptin levels were compared among all groups.

Results

Serum 5-HT levels were lower and NE and leptin levels were higher in the LPE group compared to the SPE, NPE, and non-PE groups (P < .05). However, serum 5-HT, leptin, and NE levels were not significantly different among the non-PE, NPE, and SPE groups (P < .05). In addition, serum 5-HT <95.0 ng/mL, NE >543.0 ng/L, and leptin >19.8 ng/mL may be predictive indicators of LPE.

Clinical Significance

Based on serum 5-HT, NE, and leptin levels, LPE can be distinguished from SPE and NPE, which provides an objective basis for the treatment of PE.

Strengths and Limitations

There is no effective method to classify PE. The main limitation of this study is the limited sample size.

Conclusion

The serum 5-HT, leptin, and NE levels in PE patients may contribute to the classification of PE.

Sperm recovery from urine in men with retrograde ejaculation

Introduction

Retrograde ejaculation (RE) consists of the reflux backwards, towards the bladder, of the ejaculate, during the emission phase of ejaculation, causing a total or partial absence of sperm emission, with the consequent diversion of semen into the bladder during the emission phase of ejaculation. Evaluating the ejaculate may not be sufficient for identifying RE in some patients. Hence, the management of infertility may involve the use of invasive methods such as epididymal fluid retrieval or testicular biopsy.

Content

This paper defines RE and methods for its diagnosis. A description is also provided of the techniques used for the detection of sperm in post-ejaculatory urine (PEU), the preparation and retrieval of sperm from urine and their subsequent use in assisted reproductive techniques.

Summary

The diagnosis of RE is based on the detection of spermatozoa in PEU in patients with aspermia or oligozoospermia and low or normal seminal volume. Although the presence of sperm in PEU could be sufficient for a diagnosis of RE, there is a lack of consensus regarding the diagnostic criteria for PEU, and the literature available is very limited. A correct diagnosis of RE allows the use of PEU for recovering sperm and its subsequent use in assisted human reproduction techniques, thus avoiding invasive techniques.

Outlook

A significant number of patients with RE may remain undiagnosed. Therefore, it is essential to conduct an RE study in patients with suspicion, through the analysis of PEU, and to properly interpret the results for accurate diagnosis.

Abnormal percent amplitude of fluctuation in patients with lifelong premature ejaculation is associated with neurotransmitter profiles

Identifying additional imaging biomarkers of lifelong premature ejaculation (LPE) may provide valuable insights into understanding the underlying neural mechanisms of this disorder. Forty-six LPE patients and thirty-five healthy controls (HCs) were enrolled in this study. The Percent Amplitude of Fluctuation (PerAF) method was used to assess differences in brain function in LPE patients compared to HCs during the resting-state. Receiver operating characteristic (ROC) analysis was used to investigate the potential biomarkers based on the imaging findings. Correlation analysis was then applied to examine the relationships between the neuroimaging findings and clinical symptoms. We also investigated whether PerAF alterations in LPE patients were associated with specific neurotransmitter systems. Compared to HCs, LPE patients showed increased PerAF in the middle cingulate cortex (MCC), supramarginal gyrus, Rolandic operculum, parahippocampus/hippocampus (ParaHIPP/HIPP) as well as insula; and decreased PerAF in the precuneus, inferior temporal cortex plus occipital cortex. The MCC and ParaHIPP/HIPP exhibited higher classification performance on ROC analysis. Positive correlations were found between the Premature Ejaculation Diagnostic Tool score and PerAF in the insula, and the International Index of Erectile Function score and PerAF in the precuneus. Additionally, altered PerAF in LPE patients correlated significantly with the spatial distribution of dopamine, acetylcholine and epinephrine pathways. Our findings indicate that LPE patients have PerAF-related changes in certain brain regions associated with visual, sensory and/or emotional processing, and reveal that the abnormal control of ejaculatory function may be related to the combined dysregulation of neurotransmitter systems in LPE patients.

Exploring the impact of sexual positions on ejaculation: Insights from a survey study by the Andrology Working Group of the Society of Urological Surgery in Turkey

BACKGROUND

Sexual position is one of the several aspects that affects ejaculation control, which is essential for sexual pleasure. Still little is known, nevertheless, about the connection between sexual positions and ejaculation duration.

OBJECTIVE

To investigate the impact of various sexual positions on the duration of ejaculation and gain a deeper understanding of the elements that influence the ability to control ejaculation.

METHOD

An online survey was carried out on a sample of 1904 heterosexual men between the ages of 18-65 years. Premature ejaculation (PE) diagnostic tool was used to define PE. Demographic, behavioral, and physiological traits that are linked to PE and non-PE groups were collected. The participants listed their preferred sexual positions and the ones they changed to during ejaculating. Also, analyses were performed between male/female active or deep/shallow thrust positions and PE status.

RESULTS

Although there were no appreciable variations in age or circumcision between PE and non-PE groups, the age of first sexual experience was associated with PE status. Groups also varied in the number of weekly ejaculations, the duration of the favored ejaculations, and the characteristics of the erection. The most preferred sexual posture was the doggy style regardless of the group. When the non-PE group felt to ejaculate, they preferred to change the position significantly more than the PE group (74% vs 67.2%; p < 0.05). However, when participants felt ejaculate, non-PE participants tended to switch to shallow thrusting positions significantly more than PE participants, who preferred deeper positions (27.1% vs. 18%; p < 0.05).

CONCLUSION

This study underlines the relevance of considering sexual positions in controlling PE. Modifying positions during sexual intercourse may offer a non-pharmacological therapeutic alternative for improving ejaculation control. Future studies in this field might help to create tailored PE treatment strategies.

Ethnomedicinal, phytochemical, pharmacological and toxicological profile of Mondia whitei: A review

Mondia whitei is an aromatic plant native to sub-Saharan Africa. This spice is commonly used in the treatment of various diseases, such as hypertension, diabetes, erectile dysfunction, and premature ejaculation. This review was undertaken to provide updated information on the botanical, phytochemical, pharmacological, and toxicological knowledge of this plant of high relevance to African populations. Moreover, its mechanism of action was described based on previous experimental studies. Data were compiled from various online databases such as PubMed, Google Scholar, Scopus, Science Direct, Web of Science, Springer link, Taylor and Francis, and SciFinder. Additionally, books, book chapters and proceedings were used as secondary sources. The chemical structures of phytocompounds were drawn using PubChem Sketcher program. M. whitei contains various phytocompounds, including reducing sugars, triterpenes, steroids, alkaloids, saponins, tannins, phenolics, hydrogen cyanide, carotenoid, oxalate and phytate. Moreover, para-pentylphenyl-benzoate, (-)-Loliolide, 5-chloropropacin, propacin, 2-hydroxy-4-methoxybenzaldehyde, isovanillin, 9-hexacosene, 2-hexen-1-ol, and heptacosane were isolated from this spice. M. whitei has several pharmacological benefits, including aphrodisiac, pro-fertile, pro-erectile, androgenic, antioxidant, antiparasitic, antimalarial, antibacterial, antiviral, antifungal, antiepileptic, anti-inflammatory, analgesic, antidepressant, antidiarrheal, hepatoprotective, antisickling, and anticancer activities. Toxicological studies showed an LD50 of above 5000 mg/Kg and no signs of toxicity after one week of oral treatment. The aphrodisiac effect of this spice is one of its main activities, supported by numerous experimental studies. Because M. whitei delays contractions of the bulbospongiosus muscles, its aphrodisiac effect could be mediated through the modulation of the spinal generator of ejaculation. This can justify its folkloric use in the treatment of premature ejaculation.

Altered regional brain activity and functional connectivity in primary intravaginal anejaculation patients revealed by resting-state fMRI

ABSTRACT

Ejaculation is regulated by the central nervous system. However, the central pathophysiology of primary intravaginal anejaculation (PIAJ) is unclear. The present study aimed to examine the changes in regional brain activity and functional connectivity underlying PIAJ. A total of 20 PIAJ patients and 16 healthy controls (HCs) were enrolled from September 2020 to September 2022 in the Department of Andrology, Nanjing Drum Tower Hospital (Nanjing, China). Magnetic resonance imaging data were acquired from all participants and then were preprocessed. The measures of fractional amplitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo), and functional connectivity (FC) were calculated and compared between the groups. PIAJ patients showed increased fALFF values in the left precuneus compared with HCs. Additionally, PIAJ patients showed increased ReHo values in the left precuneus, left postcentral gyrus, left superior occipital gyrus, left calcarine fissure, right precuneus, and right middle temporal gyrus, and decreased ReHo values in the left inferior parietal gyrus, compared with HCs. Finally, brain regions with altered fALFF and ReHo values in PIAJ patients showed increased FC with widespread cortical regions, which included the frontal, parietal, temporal, and occipital regions, compared with HCs. In conclusion, increased regional brain activity in the parietal, temporal, and occipital regions, and increased FC between these brain regions, may be associated with PIAJ occurrence.

Stress Biomarkers Transferred Into the Female Reproductive Tract by Seminal Plasma Are Associated with ICSI Outcomes

This study aimed to determine whether male stress is related to seminal stress biomarkers and pregnancy achievement in women exposed to their partner's seminal plasma (SP) in the intracytoplasmic sperm injection (ICSI) cycle. In this pilot prospective study, 20 couples undergoing ICSI, as well as 5 fertile sperm donors and 10 saliva donors, were investigated. Women were exposed to their partner's SP via unprotected sexual intercourse during the ICSI cycle and intravaginal application on the day of ovum pick-up (Day-OPU). Semen samples were collected from male partners by masturbation on the Day-OPU. Saliva and serum samples were collected prior to masturbation. Body fluids were frozen at - 80 °C until assayed. Biomarkers of activity of the sympathetic adrenomedullary axis (salivary alpha-amylase and adrenaline), sympathetic neural axis (noradrenaline and dopamine), hypothalamic-pituitary-adrenal (HPA) system (cortisol), and immune system (C-reactive protein and interleukin (IL)-18) were estimated to examine their association with SP composition and clinical pregnancy achievement. The clinical pregnancy rate was 45.0%. In the unsuccessful ICSI group, blunted levels of salivary and serum cortisol were found compared to the successful ICSI group and the fertile sperm donors. With regard to seminal markers, decreased cortisol level and elevated noradrenaline, noradrenaline/cortisol ratio, and lL-18 levels were strongly associated with ICSI failure (areas under the ROC curves were, 0.813, 0.848, 0.899, and 0.828, respectively). These findings confirm that stress response systems activity affects SP composition, which in turn is associated with ICSI outcomes in women exposed to their partner's SP during an ICSI cycle.

Topological differences of striato-thalamo-cortical circuit in functional brain network between premature ejaculation patients with and without depression

INTRODUCTION

Premature ejaculation (PE), a common male sexual dysfunction, often accompanies by abnormal psychological factors, such as depression. Recent neuroimaging studies have revealed structural and functional brain abnormalities in PE patients. However, there is limited neurological evidence supporting the comorbidity of PE and depression. This study aimed to explore the topological changes of the functional brain networks of PE patients with depression.

METHODS

Resting-state functional magnetic resonance imaging (rs-fMRI) data were acquired from 60 PE patients (30 with depression and 30 without depression) and 29 healthy controls (HCs). Functional brain networks were constructed for all participants based on rs-fMRI data. The nodal parameters including nodal centrality and efficiency were calculated by the method of graph theory analysis and then compared between groups. In addition, the results were corrected for multiple comparisons by family-wise error (FWE) (p < .05).

RESULTS

PE patients with depression had increased degree centrality and global efficiency in the right pallidum, as well as increased degree centrality in the right thalamus when compared with HCs. PE patients without depression showed increased degree centrality in the right pallidum and thalamus, as well as increased global efficiency in the right precuneus, pallidum, and thalamus when compared with HCs. PE patients with depression demonstrated decreased degree centrality in the right pallidum and thalamus, as well as decreased global efficiency in the right precuneus, pallidum, and thalamus when compared to those without depression. All the brain regions above survived the FWE correction.

CONCLUSION

The results suggested that increased and decreased functional connectivity, as well as the capability of global integration of information in the brain, might be related to the occurrence of PE and the comorbidity depression in PE patients, respectively. These findings provided new insights into the understanding of the pathological mechanisms underlying PE and those with depression.

Low frequency neuromuscular electrical stimulation applied to the bulbospongiosus muscle prolongs the ejaculation latency in a rat model

Premature ejaculation (PE) is common, but its true pathophysiology is not clear, and treatments are limited. We aimed to investigate the effect of neuromuscular electrical stimulation applied in different modes and frequencies to the bulbospongiosus muscle on ejaculation parameters. In this study, 24 male Wistar albino rats were used. The rats were equally divided into three groups: control, high-frequency burst (HFB) and low-frequency (LF) (n = 8 each). Neuromuscular electrical stimulation was applied to the rats for 30 min. In the HFB group, this stimulation was applied in the burst mode at 80 Hz frequency using 200 microseconds (µs) transition time. In the LF group, manual stimulation was applied using a 2 Hz frequency and 200 µs transition time. Following the intraperitoneal administration of para-chloroamphetamine at a dose of 5 mg/kg, ejaculation time, increase in basal seminal vesicle pressure, seminal vesicle maximum pressure, number and interval time of seminal vesicle contractions and bulbospongiosus muscle electromyography activities were evaluated over 30 min. There was a significant difference between the groups in terms of ejaculation time (p = 0.002). The ejaculation times of the LF, HFB and control groups were 1344.71 ± 105.9, 908 ± 62 and 672 ± 149.7 s, respectively. The post hoc analysis revealed that the ejaculation time of the LF group was significantly longer than that of the HFB and control groups (p = 0.033 and p = 0.001, respectively). The remaining parameters did not differ significantly between the groups. The results showed that low-frequency (2 Hz) electrical stimulation applied to the male rats significantly prolonged the ejaculation time. It is thus considered that applying neuromuscular electrical stimulation before planned sexual activity can prevent the rhythmic contractions necessary for completing the ejaculatory process by maintaining subtetanic continuous contraction and prolonging the ejaculation time in patients with premature ejaculation complaints.

Commonality and heterogeneity of pacemaker mechanisms in the male reproductive organs

During emission, the first phase of ejaculation, smooth muscle in organs of the male reproductive tract (MRT) vigorously contract upon sympathetic nerve excitation to expel semen consisting of sperm and seminal plasma. During inter-ejaculation phases, the epididymis, seminal vesicles and prostate undergo spontaneous phasic contractions (SPCs), this transporting and maintaining the quality of sperm and seminal plasma. Recent studies have revealed platelet-derived growth factor receptor α-expressing (PDGFRα+) subepithelial interstitial cells in seminal vesicles subserve the role of pacemaker cells that electrically drive SPCs in this organ. PDGFRα+ smooth muscle cells in the epididymis also appear to function as pacemaker cells implicating PDGFRα as a potential signature molecule in MRT pacemaking. The dominant mechanism driving pacemaking in these organs is the cytosolic Ca2+ oscillator. This operates through entrainment of the release-refill cycle of Ca2+ stores, the released Ca2+ ions opening Ca2+-activated chloride channels, including in some cases ANO1 (TMEM16A), with the resultant pacemaker potential activating L-type voltage-dependent Ca2+ channels in the smooth muscle causing contraction (viz. SPCs). A second pacemaker mechanism, namely the membrane oscillator also has a role in specific cases. Further investigations into the commonality and heterogeneity of MRT pacemakers will open an avenue for understanding the pathogenesis of male infertility associated with deterioration of seminal plasma.

The association of reproductive hormones, thyroid function, and vitamin levels with premature ejaculation: A prospective case-control study

PURPOSE

To investigate whether serum hormone (testosterone, prolactin, gonadotropins, and thyroid hormones) and vitamin (vitamin B12, folic acid, and vitamin D) levels are associated with premature ejaculation (PE).

MATERIALS AND METHODS

This prospective case-control study included 126 patients with PE (lifelong PE [LPE] in 94 and acquired PE [APE] in 32) who presented to the urology outpatient clinic between April 2016 and January 2023 and 92 healthy men as a control group. The diagnosis of PE was based on the criteria defined by the International Society for Sexual Medicine. Serum total testosterone (TT), free and bioavailable testosterone, follicle-stimulating hormone, luteinizing hormone, prolactin, thyroid-stimulating hormone, free triiodothyronine, thyroxine (fT4), vitamin B12, folic acid, and vitamin D levels were measured.

RESULTS

Serum TT, fT4, and vitamin D levels were significantly higher in patients with PE than in the control group (p=0.022, p=0.002, and p=0.044, respectively). However, the serum vitamin B12 level was significantly lower in the PE group (p=0.021). In the multivariate logistic regression analysis, only vitamin B12 was found to be an independent risk factor for PE, with an estimated odds ratio of 0.997 (95% confidence interval 0.994-0.999, p=0.036).

CONCLUSIONS

This study demonstrated that lower vitamin B12 levels are associated with the presence of PE. Therefore, we believe that it would be beneficial to consider vitamin B12 levels in the evaluation of patients with PE.

Neurophysiology of male sexual arousal-Behavioral perspective

In the presented review, we analyzed the physiology of male sexual arousal and its relation to the motivational aspects of this behavior. We highlighted the distinction between these processes based on observable physiological and behavioral parameters. Thus, we proposed the experimentally applicable differentiation between sexual arousal (SA) and sexual motivation (SM). We propose to define sexual arousal as an overall autonomic nervous system response leading to penile erection, triggered selectively by specific sexual cues. These autonomic processes include both spinal and supraspinal neuronal networks, activated by sensory pathways including information from sexual partner and sexual context, as well as external and internal genital organs. To avoid misinterpretation of experimental data, we also propose to precise the term "sexual motivation" as all actions performed by the individual that increase the probability of sexual interactions or increase the probability of exposition to sexual context cues. Neuronal structures such as the amygdala, bed nucleus of stria terminalis, hypothalamus, nucleus raphe, periaqueductal gray, and nucleus paragigantocellularis play crucial roles in controlling the level of arousal and regulating peripheral responses via specific autonomic effectors. On the highest level of CNS, the activity of cortical structures involved in the regulation of the autonomic nervous system, such as the insula and anterior cingulate cortex, can visualize an elevated level of SA in both animal and human brains. From a preclinical perspective, we underlie the usefulness of the non-contact erection test (NCE) procedure in understanding factors influencing sexual arousal, including studies of sexual preference in animal models. Taken together results obtained by different methods, we wanted to focus attention on neurophysiological aspects that are distinctly related to sexual arousal and can be used as an objective parameter, leading to higher translational transparency between basic, preclinical, and clinical studies.

One-drop chemosensing of dapoxetine hydrochloride using opto-analysis by multi-channel μPAD decorated silver nanoparticles: introducing a paper-based microfluidic portable device/sensor toward naked-eye pharmaceutical analysis by lab-on-paper technology

Dapoxetine (DPX) belongs to the selective serotonin reuptake inhibitor (SSRI) class and functions by blocking the serotonin transporter and increasing serotonin activity, thereby delaying ejaculation. Therefore, monitoring of the concentration of DPX in human biofluids is important for clinicians. In this study, application of silver nanoparticles with the morphology of prisms (AgNPrs) for the sensitive measurement of DPX using colorimetric chemosensing and the spectrophotometric method was investigated. Also, DPX was determined in real samples using the spectrophotometry method. Based on the obtained results, all of the detection process in colorimetric assay is related to morphological reform of AgNPrs after it's specific electrostatic and covalent interaction with DPX as analyte. The UV-vis results indicate that the proposed AgNPrs-based chemosensing system has a wide range of linearity (0.01 μM to 1 mM) with a low limit of quantification of 0.01 μM in human urine samples, which is suitable for clinical analysis of this drug in human urine samples. It is important to point out that, this chemosensing strategy showed inappropriate analytical results for the detection of DPX in human urine samples which is a novelty of this platform. Finally, the optimized microfluidic paper-based analytical device (μPAD) was integrated with the colorimetric analysis of DPX to provide a time/color system for estimating analyte concentration by a portable substrate toward in situ and on-site biomedical analysis. Interestingly, the analytical validation tests showed appropriate results with great stability, which may facilitate commercialization of the engineered substrate. For the first time, in order to provide a simple and portable colorimetric/spectrophotometric recognition system to sensitive determination of DPX, an optimized pump-less microfluidic paper-based colorimetric device (μPCD) was introduced and validated for the real-time biomedical analysis of this analyte. According to the obtained results, this alternative approach is suitable for therapeutic drug monitoring (TDM) and biomedical analysis by miniaturized and cost-beneficial devices.

Evaluating the Impact of Benign Prostatic Hyperplasia Surgical Treatments on Sexual Health

Benign prostatic hyperplasia (BPH), a prevalent condition in older men, is often managed through various surgical interventions. This narrative review aims to explore the impact of these surgical treatments on sexual function, a critical aspect of patient quality of life often overlooked in BPH management. The methodology encompassed a thorough review of contemporary surgical techniques for BPH, including prostate resection, enucleation, vaporization, and minimally invasive therapies such as UroLift, Rezum, and Aquablation. Additionally, the focus was on patient-centered outcomes, with a special emphasis on sexual health following surgery. Findings reveal that, while surgical interventions effectively alleviate BPH symptoms, they often have significant repercussions in sexual function, including erectile and ejaculatory dysfunction. However, emerging techniques demonstrate potential in preserving sexual function, underscoring the need for patient-centric treatment approaches. The study highlights the complex interplay between BPH surgery and sexual health, with minimally invasive treatments showing promise in balancing symptom relief and sexual function preservation. In conclusion, the study advocates for an integrated, interdisciplinary approach to BPH treatment, emphasizing the importance of considering sexual health in therapeutic decision-making. This narrative review suggests a paradigm shift towards minimally invasive techniques could optimize patient outcomes, marrying symptom relief with quality-of-life considerations. The need for further research in this domain is evident, particularly in understanding long-term sexual health outcomes following different surgical interventions for BPH.

Orexin receptors in paraventricular nucleus influence sexual behavior via regulating the sympathetic outflow in males

BACKGROUND

Orexins are hypothalamic neuropeptides associated with various neurophysiological activities such as sleep, arousal, and reward. However, there are few studies investigating the relationships between orexin receptors in the paraventricular nucleus and sexual behaviors.

OBJECTIVES

To explore the roles of orexin receptors in the paraventricular nucleus on sexual behaviors and uncover its potential mechanisms in males.

MATERIALS AND METHODS

Orexin A, orexin 1 receptor antagonist SB334867, and orexin 2 receptor antagonist TCS-OX2-29 were microinjected into the paraventricular nucleus to investigate the effects of orexin receptors on copulatory behavior testing of C57BL/6 mice. To explore if ejaculation could activate orexin 1 receptor-expressing neurons in the paraventricular nucleus, fluorescence immunohistochemical double staining was utilized. The levels of serum norepinephrine were measured and the lumbar sympathetic nerve activity was recorded to reflect the sympathetic nervous system activity. Moreover, the bulbospongiosus muscle-electromyogram was recorded and analyzed. To test whether perifornical/lateral hypothalamic area orexinergic neurons directly projected to the paraventricular nucleus, virus retrograde tracing technology was utilized.

RESULTS

Orexin A significantly enhanced sexual performance by shortening the intromission and ejaculation latencies, and increasing the mount and intromission frequencies, while the opposite outcomes appeared with SB334867. However, TCS-OX2-29 had no significant effects on sexual behaviors. Moreover, orexin A increased lumbar sympathetic nerve activity and the levels of serum norepinephrine, while SB334867 decreased lumbar sympathetic nerve activity and norepinephrine, which caused a significant decrease in sympathetic nervous system outflow. Meanwhile, a robust increase in the bulbospongiosus muscle-electromyogram activity was identified after microinjecting orexin A. Furthermore, cFos immunopositive cells were increased and double stained with orexin 1 receptor-expressing neurons in the mating group. Additionally, the retrograde tracing results demonstrated that orexinergic neurons in the perifornical/lateral hypothalamic area directly projected to the paraventricular nucleus.

CONCLUSIONS

Orexin 1 receptor in the paraventricular nucleus could influence the ejaculatory reflex via mediating the sympathetic nervous system activity, which might be of great importance in the treatment of premature ejaculation in the future.

The elusive concept of sexual motivation: can it be anchored in the nervous system?

Sexual motivation is an abstract concept referring to the mechanisms determining the responsivity to sexually relevant stimuli. This responsivity determines the likelihood of producing a sexual response and the intensity of that response. Both responsivity to stimuli and the likelihood of making a response as well as the intensity of response are characteristics of an individual. Therefore, we need to assume that the concept of sexual motivation materializes in physiological mechanisms within the individual. The aim of the present communication is to analyze the requisites for the endeavor to materialize sexual motivation. The first requisite is to provide an operational definition, making the concept quantifiable. We show that parameters of copulatory behavior are inappropriate. We argue that the intensity of sexual approach behaviors provides the best estimate of sexual motivation in non-human animals, whereas the magnitude of genital responses is an exquisite indicator of human sexual motivation. Having assured how to quantify sexual motivation, we can then proceed to the search for physiological or neurobiological underpinnings. In fact, sexual motivation only manifests itself in animals exposed to appropriate amounts of gonadal hormones. In female rats, the estrogen receptor α in the ventrolateral part of the ventromedial nucleus of the hypothalamus is necessary for the expression of sexual approach behaviors. In male rats, androgen receptors within the medial preoptic area are crucial. Thus, in rats sexual motivation can be localized to specific brain structures, and even to specific cells within these structures. In humans, it is not even known if sexual motivation is materialized in the brain or in peripheral structures. Substantial efforts have been made to determine the relationship between the activity of neurotransmitters and the intensity of sexual motivation, particularly in rodents. The results of this effort have been meager. Likewise, efforts of finding drugs to stimulate sexual motivation, particularly in women complaining of low sexual desire, have produced dismal results. In sum, it appears that the abstract concept of sexual motivation can be reliably quantified, and the neurobiological bases can be described in non-human animals. In humans, objective quantification is feasible, but the neurobiological substrate remains enigmatic.

Mating in the cold. Prolonged sperm storage provides opportunities for forced copulation by male bats during winter

In a wide range of heterothermic mammals, hibernation interrupts the reproductive cycle by forcing reproductive delays. In hibernating bats with delayed fertilization, an opportunity for sperm competition is enhanced by extending a time-window between copulations and fertilization. In order to achieve greater fertilization success, males are expected to show adaptations for sperm competition by increasing their opportunities for mating over an extended period. We aimed to clarify the physiological and behavioral characteristics of male bats experiencing increased risks of sperm competition. We investigated the characteristics of the reproductive cycle of the little horseshoe bat (Rhinolophus cornutus), and examined whether males retain reproductive physiology related to sexual behavior, and attempt to copulate with females even during the hibernation period. Field observations and histological examinations of the reproductive cycle confirmed that females, having mated in the autumn, store spermatozoa in the uterus during hibernation and give birth in the early summer to just one offspring per year, thus males face a low certainty of successful fertilization. Although their testes regressed rapidly and their testosterone levels were lower during winter than in autumn, males stored motile spermatozoa in their cauda epididymides from autumn throughout the winter. During hibernation, we found that males occasionally aroused from torpor and attempted to mate forcibly with torpid females. Forced copulations appear to increase a male's chances of obtaining a mate while avoiding pre-copulatory female choice. Epididymal sperm storage could be advantageous for males in allowing them to extend their potential mating period even though their testes have regressed. We also found that some hibernating nulliparous females were ready for fertilization in spring after hibernation, whereas few parous females appeared in the same roost. In contrast to males, forced copulations would be maladaptive for females because they cannot opt for higher-quality males while in torpor. Females that have experienced sexual coercion when young may subsequently avoid hibernacula where adult males are present.

Long COVID and risk of erectile dysfunction in recovered patients from mild to moderate COVID-19

Patients with coronavirus disease 2019 (COVID-19) were shown to have reduced serum testosterone levels compared to healthy individuals. Low testosterone levels are linked with the development of erectile dysfunction (ED). In this case-controlled study, 20 healthy controls and 39 patients with ED 3 months after recovering from mild-to-moderate COVID-19 pneumonia were studied. The patients ranged in age from 31 to 47 years. To identify early and late COVID-19 infections, real-time polymerase-chain reaction (RT-PCR) and COVID-19 antibody testing were done. The levels of luteinizing hormone (LH), follicular stimulating hormone (FSH), total testosterone (TT), free testosterone (FT), free androgenic index (FAI), and sex hormone-binding globulin (SHBG) were measured. The sexual health inventory for patients (SHIM) score was used to measure the erectile function of the patients and controls. When compared to the controls, the TT serum level in long COVID-19 (LC) patients with ED was low (p = 0.01). In contrast to controls, FT and FAI were both lower in LC patients with ED. (p = 0.001). FSH serum levels did not significantly differ (p = 0.07), but in ED patients, LH serum levels were elevated. SHIM scores were associated with low TT (p = 0.30), FT (p = 0.09), and high LH (p = 0.76) in LC patients with ED. Male patients with decreased serum levels of LH and testosterone may have hypothalamic-pituitary-gonadal axis dysfunction, which could lead to the development of LC-induced ED. Therefore, an in-depth research is necessary to confirm the causal link between COVID-19 and ED in LC patients.

Remote spinal trauma resulting in dorsal column spinal pathway dysfunction and anejaculation

Spinal cord injury (SCI) as the cause of anejaculation is a rare entity. We present the case of a 65-year-old male with a five-year history of intractable anejaculation. Two years prior to onset of his anejaculation, the patient fell from height, causing minor spinal trauma, with sequelae of cervical myelopathy and eventual posterior spinal fusion of C1/C2. Biothesiometry and sensory evaluation revealed diminished somatic sensation of his glans penis in a frequency-dependent pattern. The patient's pudendal sensory loss and anejaculation correlate with his spinal trauma, as evidenced by the lack of peripheral nervous system findings upon neurological exam and imaging.

Clinical Safety of a Pharmaceutical Formulation Containing an Extract of Acmella oleracea (L.) in Patients With Premature Ejaculation: A Pilot Study

Acmella oleracea (L.) R. K. Jansen (Asteraceae) is a plant species widely used in traditional Amazonian medicine to treat sexual dysfunction. The use of this plant has gained popularity because of its sensory properties, such as a tingling sensation. In this study on patients with premature ejaculation, we evaluated the clinical action of a nano-formulation containing an ethanolic extract of A. oleracea inflorescences. Major constituents in the extracts were identified based on gas chromatographic analysis. Participants used a spray preparation based on the A. oleracea extract for 12 weeks, during which they were instructed to apply the product 5 min prior to sexual intercourse. To assess therapeutic efficacy, participants were required to record the mean intravaginal latency time for ejaculation (IELT). During the period of spray treatment, the nano-formulation of A. oleracea increased participant IELT values (M = 293 s) compared with the baseline values (193 s). This nano-formulation reported clinical action in patients with premature ejaculation. It is accordingly considered to have potential application as a therapeutic alternative with benefits for both patients and their partners. Given the small number of participants in this study, further multicenter studies involving a larger number of participants are needed to confirm these observations.

Ejaculatory Duct Obstruction Affects Seminal Vesicle Contractile Efficacy and Smooth Muscle Ultrastructure in a Rat Model

The purpose of this study was to investigate the effects of ejaculatory duct obstruction (EDO) on contractile efficacy, smooth muscle ultrastructure, and α1A and M3 receptors of rat seminal vesicles (SVs). A total of 48 male rats, aged 14-15 weeks, were randomly divided into three groups, namely, the control, complete EDO, and partial EDO. SV tissues were collected at 4 and 8 weeks postoperatively for further experiments. Results revealed a marked reduction in SV contractile efficacy over time following obstruction in the complete EDO group. The contractile force and frequency decreased and increased in the partial EDO group at week 4, respectively, whereas contractile efficacy significantly reduced at week 8. Moreover, obstruction resulted in significant downregulation in expression of α1A and M3 proteins and mRNAs in rats from the complete EDO group over time. Rats in the partial EDO group initially exhibited an increase followed by a decrease. Analysis of the ultrastructure of SV smooth muscles confirmed the above changes. In conclusion, complete EDO can lead to a progressive decrease in contractile efficiency of SVs. On the other hand, partial EDO can first compensate for the contraction of SVs and gradually decompensate afterwards.

Understanding and treating ejaculatory dysfunction in men with diabetes mellitus

Diabetes mellitus is a rapidly rising metabolic disorder with important systemic complications. Global figures have demonstrated the prevalence of diabetes mellitus has almost quadrupled from 108 million in 1980 to 422 million in 2014, with a current prevalence of over 525 million. Of the male sexual dysfunction resulting from diabetes mellitus, significant focus is afforded to erectile dysfunction. Nevertheless, ejaculatory dysfunction constitutes important sexual sequelae in diabetic men, with up to 35%-50% of men with diabetes mellitus suffering from ejaculatory dysfunction. Despite this, aspects of its pathophysiology and treatment are less well understood than erectile dysfunction. The main disorders of ejaculation include premature ejaculation, delayed ejaculation, anejaculation and retrograde ejaculation. Although ejaculatory dysfunction in diabetes mellitus can have complex multifactorial aetiology, understanding its pathophysiological mechanisms has facilitated the development of therapies in the management of ejaculatory dysfunction. Most of our understanding of its pathophysiology is derived from diabetic animal models; however, observational studies in humans have also provided useful information in elucidating important associative factors potentially contributing to ejaculatory dysfunction in diabetic men. These have provided the potential for more tailored treatment regimens in patients depending on the ejaculatory disorder, other co-existing sequelae of diabetes mellitus, specific metabolic factors as well as the need for fertility treatment. However, evidence for treatment of ejaculatory dysfunction, especially delayed ejaculation and retrograde ejaculation, is based on low-level evidence comprising small sample-size series and retrospective or cross-sectional studies. Whilst promising findings from large randomised controlled trials have provided strong evidence for the licensed treatment of premature ejaculation, similar robust studies are needed to accurately elucidate factors predicting ejaculatory dysfunction in diabetes mellitus, as well as for the development of pharmacotherapies for delayed ejaculation and retrograde ejaculation. Similarly, more contemporary robust data are required for fertility outcomes in these patients, including methods of sperm retrieval and assisted reproductive techniques in retrograde ejaculation.

Clinical value of penile sympathetic skin response to assess the efficacy of sertraline in the treatment of patients with sympathetic hyperexcitability in primary premature ejaculation

Background

The pathogenesis of primary premature ejaculation (PPE) is complex, and the pathologic basis may be an overactive sympathetic nervous system.

Aim

To investigate sertraline efficacy in patients with sympathetic hyperexcitability in PPE and clarify the value of penile sympathetic skin response (PSSR) in assessing the efficacy of sertraline for PPE treatment.

Methods

Sixty-three patients with PPE were recruited in the outpatient clinic and asked to take 50 mg of oral sertraline daily for a 4-week treatment period. Changes in intravaginal ejaculation latency time (IELT), Premature Ejaculation Diagnostic Tool, International Index of Erectile Function (IIEF-5), and PSSR latency and wave amplitude were compared before and after treatment.

Outcomes

The principal aim was to determine the relationships among sertraline efficacy, IELT, and PSSR latency and amplitude.

Results

After sertraline treatment, patients with PPE demonstrated a significant decrease in Premature Ejaculation Diagnostic Tool scores (P &lt; .001); a significant increase in IELT, PSSR latency, and wave amplitude (P &lt; .001); and no significant change in International Index of Erectile Function scores (P &gt; .05). Moreover, the latency changes of PSSR were positively correlated with the increment of IELT (r = 0.550, P &lt; .001). In addition, there was some degree of improvement vs pretreatment, although IELT and PSSR latencies were significantly shorter after drug discontinuation when compared with posttreatment (both P &lt; .001).

Clinical Implications

We aimed to find an objective test that accurately reflects the efficacy of treatment for sympathetic hyperexcitability in PPE.

Strengths and Limitations

The strengths include a well-powered study, use of validated instruments, and self-assessment of treatment benefit. The limitations include the single-center design, relatively short-term follow-up, and lack of more comprehensive monitoring between treatment and drug discontinuation.

Conclusion

These findings suggest that sertraline is effective for PPE treatment, that its efficacy can be partially maintained even after drug discontinuation, and that PSSR may be reliable for evaluating treatment success in patients with PPE.

The Role of Sympathetic Nerves in Osteoporosis: A Narrative Review

Osteoporosis, a systemic bone disease, is characterized by decreased bone density due to various reasons, destructed bone microstructure, and increased bone fragility. The incidence of osteoporosis is very high among the elderly, and patients with osteoporosis are prone to suffer from spine fractures and hip fractures, which cause great harm to patients. Meanwhile, osteoporosis is mainly treated with anti-osteoporosis drugs that have side effects. Therefore, the development of new treatment modalities has a significant clinical impact. Sympathetic nerves play an important role in various physiological activities and the regulation of osteoporosis as well. Therefore, the role of sympathetic nerves in osteoporosis was reviewed, aiming to provide information for future targeting of sympathetic nerves in osteoporosis.

Current and emerging treatment options for premature ejaculation

Premature ejaculation (PE) is a prevalent male sexual dysfunction. Current standard treatment regimens include behavioural therapies, topical anaesthetics, dapoxetine and other selective serotonin reuptake inhibitors (SSRIs). Most of the pharmacotherapeutic options target neurotransmitters (such as serotonin and oxytocin) that have a role in the ejaculation mechanism. However, these treatments are mildly effective and only provide a temporary delay in the ejaculation latency time, and PE recurs when the treatment is stopped. Thus, a treatment for PE is urgently needed and research is ongoing to find the ideal PE therapy. The efficacy and safety of topical anaesthetics and SSRIs in delaying ejaculation have been confirmed in many well-designed controlled trials. Both preclinical and clinical studies on new-generation SSRIs are ongoing. Moreover, promising results came from clinical trials in which the efficacy of on-demand PE therapies targeting neurotransmitters other than serotonin, such as α1-adrenoceptor antagonists and oxytocin antagonists, was assessed. Surgical intervention and neuromodulation have been proposed as potential treatment options for PE; however, current PE guidelines do not recommend these treatments owing to safety concerns.

Levosulpiride for Premature Ejaculation: A Systematic Review and Meta-Analysis

Premature ejaculation (PE) is one of the major causes of sexual dysfunction. Levosulpiride is an off-label medicine used to treat PE, but no review on its efficacy exists. A systematic review and meta-analysis was performed to determine the efficacy of levosulpiride in treating PE. Databases PubMed, Science Direct, and Google Scholar were searched. Randomized control trials (RCTs) comparing levosulpiride with placebo or other medicine were selected. Odds ratio (OR) of improved intravaginal ejaculation latency time (IELT) was calculated. A total of 97 articles were retrieved from database search, of which only four RCTs containing 203 men met the selection criteria. All four RCTs were included in systematic review while only two were included in meta-analysis. A high selection and detection bias was found in both of these studies. Meta-analysis also showed the odds of improving IELT in PE patients using levosulpiride to be significantly higher (p < .05) compared with those who used placebo, OR: 100.81, 95% confidence interval (CI) [13.12-774.90], I2 = 0%. Odds of improving IELT for > 5 min (500% improvement) were also significantly higher (p < .05) compared with the placebo groups (OR: 38.88, 95% CI [5.12-295.29], I2 = 0%). The odds of improving IELT for > 1 min, but < 5 min were also significantly higher (p < .05) than placebo groups (OR: 32.84, 95% CI [4.15-259.75], I2 = 0%). Levosulpiride improved IELT, but even so, limited studies are available on this topic. Additional research is thus required to support the present review's findings.

Delayed Ejaculation After Lumbar Spine Surgery: A Claims Database Analysis

STUDY DESIGN

Retrospective cohort.

OBJECTIVES

Delayed ejaculation (DE) is a distressing condition characterized by a notable delay in ejaculation or complete inability to achieve ejaculation, and there are no existing reports of DE following lumbar spine surgery. Inspired by our institutional experience, we sought to assess national rates of DE following surgery of the lumbar spine.

METHODS

We queried the Optum De-identified Clinformatics Database for adult men undergoing surgery of the lumbar spine between 2003 and 2017. The primary outcome was the development of DE within 2 years of surgery. Multivariable logistic regression was performed to identify factors associated with the development of DE.

RESULTS

We identified 117 918 men who underwent 162 646 lumbar spine surgeries, including anterior lumbar interbody fusion (ALIF), posterior lumbar fusion (PLF), and more. The overall incidence of DE was 0.09%, with the highest rate among ALIF surgeries at 0.13%. In multivariable analysis, the odds of developing DE did not vary between anterior/lateral lumbar interbody fusion, PLF, and other spine surgeries. A history of tobacco smoking (OR = 1.47, 95% CI 1.00-2.16, P = .05) and obesity (OR = 1.56, 95% CI 1.00-2.44, P = .05) were associated with development of DE.

CONCLUSIONS

DE is a rare but distressing complication of thoracolumbar spine surgery, and patients should be queried for relevant symptoms at postoperative visits when indicated.

Neurons for Ejaculation and Factors Affecting Ejaculation

Simple Summary

Sexual dysfunctions are rarely discussed in our current society. Males experience different sexual dysfunctions, including erectile, infertility, and ejaculatory dysfunctions. In this review only the ejaculatory dysfunction will be discussed. Ejaculation is defined as the ejection of contents collectively from the vas deferens, seminal vesicle, prostate and Cowper’s glands. It is completely controlled by a population of neurons present in the lumbar spinal cord. The presence of lesion in these neurons ceases the ejaculatory behavior in males. This population of neurons was first identified in rats; however, recently it was confirmed that these neurons are present in human males as well. The issues are known as ejaculatory dysfunction. The following are the different types of ejaculatory dysfunctions: early ejaculation, ejaculation into the urinary bladder, late ejaculation and no ejaculation.

Abstract

Ejaculation is a reflex and the last stage of intercourse in male mammals. It consists of two coordinated phases, emission and expulsion. The emission phase consists of secretions from the vas deferens, seminal vesicle, prostate, and Cowper’s gland. Once these contents reach the posterior urethra, movement of the contents becomes inevitable, followed by the expulsion phase. The urogenital organs are synchronized during this complete event. The L3–L4 (lumbar) segment, the spinal cord region responsible for ejaculation, nerve cell bodies, also called lumbar spinothalamic (LSt) cells, which are denoted as spinal ejaculation generators or lumbar spinothalamic cells [Lst]. Lst cells activation causes ejaculation. These Lst cells coordinate with [autonomic] parasympathetic and sympathetic assistance in ejaculation. The presence of a spinal ejaculatory generator has recently been confirmed in humans. Different types of ejaculatory dysfunction in humans include premature ejaculation (PE), retrograde ejaculation (RE), delayed ejaculation (DE), and anejaculation (AE). The most common form of ejaculatory dysfunction studied is premature ejaculation. The least common forms of ejaculation studied are delayed ejaculation and anejaculation. Despite the confirmation of Lst in humans, there is insufficient research on animals mimicking human ejaculatory dysfunction.

A Comprehensive Guide to Sperm Recovery in Infertile Men with Retrograde Ejaculation

Retrograde ejaculation (RE) is a condition defined as the backward flow of the semen during ejaculation, and when present can result in male infertility. RE may be partial or complete, resulting in either low seminal volume or complete absence of the ejaculate (dry ejaculate). RE can result from anatomic, neurological or pharmacological conditions. The treatment approaches outlined are determined by the cause. Alkalinizing urinary pH with oral medications or by adding sperm wash media into the bladder prior to ejaculation may preserve the viability of the sperm. This article provides a step-by-step guide to diagnose RE and the optimal techniques to retrieve sperm.

Urethral pressure profile during ejaculation in men with spinal cord injury

Ejaculation is often impaired in men with spinal cord injury (SCI). The aim of this prospective study was to assess sequence of sphincteric events and ejaculation dyssynergia during penile vibratory stimulation (PVS) in SCI men. Simultaneous recordings of bladder, bladder neck, prostate and external urethral sphincter pressures were performed using a microtip catheter with 5 pressure transducers. Between 2017 and 2019, ten men participated in the study for a total of 17 procedures. Antegrade ejaculation was found in three men with upper motor neuron (UMN) lesion. Ejaculation was preceded by a progressive increase in all urethral pressures, reaching sustained (plateau) or intermittent peaks above 220 cm H₂0. Antegrade ejaculation occurred after intermittent decreases in pressure at the external urethral sphincter level down to 100 cm H₂0, while the pressure at the bladder neck remained high (up to or above 220 cm H₂0). PVS was ineffective in eliciting ejaculation in seven men. In the five patients with UMN lesions, PVS elicited an increase in the external urethral sphincter pressure (mean 51 cm H₂0), while there was no pressure change in the two patients with lower motor neuron lesions. Due to lack of enough retrograde retrieval attempts, the hypothesis of ejaculatory dyssynergia could not be verified.

Is heart rate variability a risk factor for premature ejaculation?

OBJECTIVE

The purpose of this study is to assess the parameters of heart rate variability, which is an indicator of the change in autonomic nervous system (ANS) activity, in individuals with premature ejaculation (PE).

MATERIAL AND METHODS

This study was performed by comparing 40 patients with PE (mean age, 31.2 ± 4.1 years) and 40 healthy individuals (mean age, 30.4 ± 4.8 years) without PE from May 2018 to December 2019. HRV parameters were compared between men with PE and healthy controls in 24-hour heart rhythm Holter examination.

RESULTS

In the time domain analysis, which is a subgroup of HRV, square root of differences between consecutive normal NN intervals (RMSSD), which is an indicator of parasympathetic activity, was lower in patients with PE compared with controls (P = .025). Moreover, within the frequency domain analysis, high frequency (HF), another indicator of parasympathetic activity, was lower in patients compared with controls (P = .032). Finally, the LF/HF ratio, reflecting sympathetic/parasympathetic activity ratio, was significantly higher in patients compared with controls (P = .008). Furthermore, the multivariate logistic regression analysis showed that LF/HF ratio is independently associated with PE (P = .005). The ROC curve analysis showed that the optimal cut-off value of LF/HF above 2.7 predicted PE at a sensitivity of 77.5% and specificity of 82.5% (positive predictive value: 81.5% and negative predictive value: 78.5%).

CONCLUSION

Different HRV parameters were exhibited in the comparison of patients with PE and normal controls. It suggests that the change in HRV parameters will be an indicator of imbalance in ANS and this imbalance may cause PE. Therefore, HRV analysis can be a diagnostic tool to assess altered ANS activity in patients with PE and may be considered as a rapid screening tool.

Ejaculatory dysfunction in men with diabetes mellitus

Diabetes mellitus (DM) is a metabolic disorder that is characterized by elevated blood glucose levels due to absolute or relative insulin deficiency, in the background of β-cell dysfunction, insulin resistance, or both. Such chronic hyperglycemia is linked to long-term damage to blood vessels, nerves, and various organs. Currently, the worldwide burden of DM and its complications is in increase. Male sexual dysfunction is one of the famous complications of DM, including abnormal orgasmic/ejaculatory functions, desire/libido, and erection. Ejaculatory dysfunction encompasses several disorders related to DM and its complications, such as premature ejaculation, anejaculation (AE), delayed ejaculation, retrograde ejaculation (RE), ejaculatory pain, anesthetic ejaculation, decreased ejaculate volume, and decreased force of ejaculation. The problems linked to ejaculatory dysfunction may extend beyond the poor quality of life in diabetics as both AE and RE are alleged to alter the fertility potential of these patients. However, although both diabetes patients and their physicians are increasingly aware of diabetic ejaculatory dysfunction, this awareness still lags behind that of other diabetes complications. Therefore, all these disorders should be looked for thoroughly during the clinical evaluation of diabetic men. Besides, introducing the suitable option and/or maneuvers to treat these disorders should be tailored according to each case. This review aimed to explore the most important findings regarding ejaculatory dysfunction in diabetes from pre-clinical and clinical perspectives.

Sexual dysfunction due to pudendal neuralgia: a systematic review

Background

The pudendal nerve is considered as the main nerve of sexuality. Pudendal neuralgia is an underdiagnosed disease in clinical practice. The aim of this systematic review is to highlight the role of pudendal neuralgia on sexual dysfunction in both sexes.

Methods

A PubMed search was performed using the following keywords: “Pudendal” AND “Sexual dysfunction” or “Erectile dysfunction” or “Ejaculation” or “Persistent sexual arousal” or “Dyspareunia” or “Vulvodynia”. The search involved patients having sexual dysfunction due to pudendal neuralgia. Treatment received was also reported.

Results

Five case series, seven cohort studies, two pilot studies, and three randomized clinical trials were included in this systematic review. Pudendal nerve and/or artery entrapment, or pudendal neuralgia, is a reversible cause of multiple sexual dysfunctions. Interventions such as anesthetic injections, neurolysis, and decompression are reported as potential treatment modalities. There are no studies describing the role of pudendal canal syndrome in the pathophysiology or treatment of delayed ejaculation or penile shortening.

Discussion

Pudendal neuralgia is an underestimated yet important cause of persistent genital arousal, erectile dysfunction (ED), premature ejaculation (PE), ejaculation pain, and vulvodynia. Physicians should be aware of this entity and examine the pudendal canal in such patients before concluding an idiopathic cause of sexual dysfunction.

Aging-related markers in rat urine revealed by dynamic metabolic profiling using machine learning

The process of aging and metabolism is intimately intertwined; thus, developing biomarkers related to metabolism is critical for delaying aging. However, few studies have identified reliable markers that reflect aging trajectories based on machine learning. We generated metabolomic profiles from rat urine using ultra-performance liquid chromatography/mass spectrometry. This was dynamically collected at four stages of the rat's age (20, 50, 75, and 100 weeks) for both the training and test groups. Partial least squares-discriminant analysis score plots revealed a perfect separation trajectory in one direction with increasing age in the training and test groups. We further screened 25 aging-related biomarkers through the combination of four algorithms (VIP, time-series, LASSO, and SVM-RFE) in the training group. They were validated in the test group with an area under the curve of 1. Finally, six metabolites, known or novel aging-related markers, were identified, including epinephrine, glutarylcarnitine, L-kynurenine, taurine, 3-hydroxydodecanedioic acid, and N-acetylcitrulline. We also found that, except for N-acetylcitrulline (p < 0.05), the identified aging-related metabolites did not differ between tumor-free and tumor-bearing rats at 100 weeks (p > 0.05). Our findings reveal the metabolic trajectories of aging and provide novel biomarkers as potential therapeutic antiaging targets.

Changes in salivary proteins can reflect beneficial physiological effects of ejaculation in the dog

The objective of this study was to study the changes in salivary proteins that occur in the dog after the ejaculation process. Saliva samples from eight dogs before and after induced ejaculation were analyzed by proteomic using Tandem Mass Tag (TMT) labeling and LC-MS/MS analysis. A total of 33 salivary proteins showed significant changes after the ejaculation process. The up-regulated proteins that showed changes of higher magnitude were mucin-7 (MUC-7), peroxiredoxin-4 (PRDX4) and galectin-3 (LEGALS3) whereas proteins such as alpha-1-acid glycoprotein (A1G1) and alpha-1B-glycoprotein (A1BG) were the most down-regulated. MUC-7 and PRDX4 expression in saliva after ejaculation could be associated with the protective "environment" created by the organism to exert pr 3o-fertility activities and antioxidants benefits in spermatozoa. Also LEGALS3 increment could be associated with an improvement of wellbeing and could contribute to a positive global effect in the body. Down-regulations of A1G1 and A1GB proteins found in saliva after ejaculation could be associated with a reduction in systemic inflammation. Overall it can be concluded that, changes in proteins in saliva that are produced after ejaculation can reflect a state of increase immune defenses, improvement of antioxidant status and low inflammation.

In Vitro Contraction of Isolated Cauda Epididymal Duct Smooth Muscle as a Complimentary Approach to Physiological, Pathological, Toxicological, and Pharmacological Studies on Epididymal Function

Contraction of cauda epididymal duct (CE) smooth muscle is one of the very first events of the seminal emission phase of ejaculation. The contraction of CE smooth muscle is governed by a complex interaction of hormones, autacoids, and by the neurotransmitters released from the epididymal intramural nerve endings, and any impairment in the CE smooth muscle contraction has the potential to impair male fertility. Apart the obvious pathophysiological and toxicological importance of CE smooth muscle contraction, modulation of CE contraction has pharmaceutical interest offering a druggable target to development of drugs to improve/impair male fertility. The in vitro contraction experiments constitute a valuable approach to an in-depth evaluation of functional and molecular changes resulting from pathologies or drug exposure. Therefore, this chapter consists in a description of in vitro pharmacological reactivity contractility of the epididymal duct in a controlled medium, maintained at 30 °C of temperature and continuously bubbled with 95% O₂ and 5% CO₂ to obtain cumulative concentration-response curves that has been fundamental to some of our investigations on epididymal physiology, toxicology, and pharmacology.

Abnormal Thalamic Metabolism in Patients With Lifelong Premature Ejaculation

BACKGROUND

Although some recent neuroimaging studies have indicated the abnormal brain structure or function in patients with lifelong premature ejaculation (LPE), whether and how the abnormal thalamic function participates in processing sexual behavioral information are still unclear in patients with LPE.

AIM

The aim of this study was to assess the changes in the thalamus metabolism and structural integrity in patients with LPE.

METHODS

We performed a multimodal magnetic resonance approach in a 3.0 T system, including proton magnetic resonance spectroscopy (¹H-MRS), diffusion tensor imaging, and volumetric analysis to detect the differences in thalamic metabolism and structure between 20 patients with LPE and 15 healthy controls.

OUTCOMES

We analyzed and correlated the clinical symptoms of the subjects with significant ¹H-MRS-based features. Peak areas of N-acetylaspartate, choline, creatine (Cr), and glutamate/glutamine (Glu) were calculated with the LCModel software.

RESULTS

Diffusion tensor imaging and volumetric analysis of thalami showed no differences between the 2 groups. On the contrary, ¹H-MRS study disclosed that both Glu concentrations and Glu/Cr ratio values in the thalami of patients with LPE were remarkably increased when compared with healthy controls (P < .01 for both variables). In addition, both the intravaginal ejaculatory latency time score and Chinese Index of Sexual Function for Premature Ejaculation-5 score were negatively related to increased Glu concentrations and Glu/Cr ratio values.

CLINICAL IMPLICATIONS

Glutamatergic activity changes of thalamus may be an underlying indicator for evaluating sensory conduction efficiency in patients with LPE.

STRENGTHS & LIMITATIONS

The present study first found the abnormal thalamic metabolism in patients with LPE and contributed to a better understanding of the LPE etiology. Limitations include a cross-sectional study design with small samples and no examination of other brain areas.

CONCLUSION

Our findings show that the increase in glutamatergic activity of thalamus is related to LPE, suggesting that the increased Glu neurotransmission in the thalamus may contribute to the development of premature ejaculation. Xia J-D, Chen F, Zhang Q-J, et al. Abnormal Thalamic Metabolism in Patients With Lifelong Premature Ejaculation. J Sex Med 2021;18:275-283.

Spontaneous Ejaculation: A Focused Review for the Clinicians

INTRODUCTION

The process of ejaculation has important meanings not only for its association with orgasm but also for the timing to ejaculate in the context of sexual activity. Spontaneous (involuntary) ejaculation (SE) without any sexual stimulation is a distressing symptom. Our understanding of SE is limited. Unfortunately, many physicians are not aware of these cases.

OBJECTIVES

The objective of this study is to describe the etiopathogenesis, clinical features, diagnosis, and treatment options for SE.

METHODS

We searched the literature for publications on "SE," "spontaneous emission" or "involuntary ejaculation," and factors influencing SE in the PUBMED/MEDLINE, Scopus, Cochrane Library, EMBASE, PsycINFO, ProQuest, Academic Search Complete database, Google Scholar, and CINAHL databases from inception to August 2020.

RESULTS

The literature search yielded 36 relevant publications reporting on 43 patients with SE. Attempts to explain the cause of pathologic SE have included 4 etiological groups (spinal cord lesions, psychological causes, rabies, and drug-induced). The underlying mechanisms responsible for induction of SE may include increased adrenergic activity, overactivity in dopaminergic system, decreased serotonergic activity, damage of descending inhibitory pathway, or penile hyperexcitability. SE may occur in the absence of an identifiable trigger or may be triggered by non-sexual circumstances (micturition, defecation, glans touch, anxiety, panic attack, or school examinations). Treatment options include psychoanalytic treatment, paroxetine, citalopram, sertraline, silodosin, and anxiolytics. In drug-induced SE, dose reduction and drug withdrawal with or without switching to another drug may relief SE.

CONCLUSIONS

SE is one of the least reported ejaculatory dysfunction. The key feature shared in common by these men is SE without any sexual thoughts or fantasies, may be triggered by non-sexual contexts, rarely associated with orgasm or erection. Treatment by psychoanalytic treatment and pharmacotherapy may be helpful. Further research might explore the definite underlying mechanisms. Abdel-Hamid IA, Ali OI. Spontaneous Ejaculation: A Focused Review for the Clinicians. Sex Med Rev 2021;9:406-422.

Central Mechanisms of Apomorphine and m-Chlorophenylpiperazine on Synergistic Action for Ejaculation in Rats

BACKGROUND

We previously reported that the combination of the dopamine (DA) receptor agonist apomorphine and the 5-hydroxytryptamine (5-HT₂) receptor agonist m-chlorophenylpiperazine (m-CPP) in rats potently and selectively facilitates the ejaculatory response through activation of D₂-like and 5-HT_2C receptors, respectively.

AIM

The aim of this study was to clarify the target level of the proejaculatory effects induced by combination of these agonists.

METHODS

For in vivo behavioral studies, apomorphine and m-CPP were given intracerebroventricularly and intrathecally alone or in combination with either drug administered systemically. Male rats were acclimated to observational cages bedded in paper towels, and the occurrence of ex copula ejaculation was assessed by evaluating the presence and weight of ejaculatory plugs dropped from the tip of the penis to the paper towels or adhered to the tip of the penis at 30 min after drug administration. For in vitro contraction studies, seminal vesicles isolated from rats were suspended in an organ bath to test contractile responses to drug combinations, and the effects of the combined drugs on the contractile response of noradrenaline were also tested.

MAIN OUTCOME MEASURES

The presence and weight of ejaculatory plugs produced by drug-induced ejaculation and the contractile responses of the seminal vesicle were evaluated.

RESULTS

Intrathecal m-CPP (10 μg), but not intracerebroventricular m-CPP, evoked the synergistic effects on ejaculation when used in combination with systemically administered apomorphine (0.1 mg/kg, subcutaneous). Moreover, the synergy between m-CPP and apomorphine was completely abolished by the intrathecal 5-HT_2C receptor antagonist SB242084 (10 μg). Intrathecal or intracerebroventricular apomorphine (1-10 μg) evoked proejaculatory effects in combination with systemically administered m-CPP (0.3 mg/kg, intraperitoneal). The selective peripherally acting D₂-like receptor agonist carmoxirole did not evoke ejaculation when used in combination with m-CPP. Furthermore, isolated rat seminal vesicles were completely insensitive to the combination of apomorphine and m-CPP.

CONCLUSION

These results indicated that the synergistic effects of the drugs on ejaculation were induced at the central level but not at peripheral sites. Our findings also suggested that the 5-HT_2C receptor mediated the stimulation of the spinal ejaculatory pattern generator and was synergistically potentiated by the spinal DA receptor and that activation of the supraspinal DA receptor was also involved in mediating these synergistic effects. Yoshizumi M, Yonezawa A, Kimura Y, et al. Central Mechanisms of Apomorphine and m-Chlorophenylpiperazine on Synergistic Action for Ejaculation in Rats. J Sex Med 2021;18:231-239.

Aberrant default mode network and auditory network underlying the sympathetic skin response of the penis (PSSR) of patients with premature ejaculation: A resting-state fMRI study

INTRODUCTION

Hyperactivity of the sympathetic nervous system is considered as an important component involved in the pathological mechanisms of premature ejaculation (PE). However, the neural mechanisms of PE with high sympathetic activity are still not well understood.

METHODS

The activity of the sympathetic innervations in the penis was evaluated by the sympathetic skin response of the penis (PSSR) with an electromyograph and evoked potential equipment. Resting-state functional magnetic resonance imaging (fMRI) data were acquired from 18 PE patients with high sympathetic activity (sPE), 17 PE patients with normal sympathetic activity (nsPE), and 24 healthy controls (HC). We investigated the neural basis of sPE based on the measure of regional homogeneity (ReHo). Moreover, the correlations between brain regions with altered ReHo and PEDT scores and PSSR latencies in the patient group were explored.

RESULTS

Altered ReHo values among three groups were found in the temporal, cingulated, and parietal cortex in the default mode network (DMN), as well as the temporal cortex in the auditory network (AUD). Compared with HC, Patients with sPE had increased ReHo values of brain regions in DMN, AUD, and decreased ReHo values of brain regions in DMN. In addition, increased ReHo values were found in DMN of patients with nsPE, while decreased ReHo values were found in DMN and the attention network (AN). Moreover, sPE patients had increased ReHo values in AUD and decreased ReHo values in DMN when compared with nsPE patients. Finally, altered ReHo values of brain regions in DMN and AUD were associated with PEDT scores and PSSR latencies in the patient group.

CONCLUSION

Our results suggested that PE patients had abnormal ReHo values in DMN, AUD, and AN. Patients with sPE were characterized by increased neuronal activity in AUD and decreased activity in DMN. This highlighted the significances of DMN, AUD, and AN in the pathophysiology of PE and also provided potential neuroimaging biomarkers for distinguishing sPE from nsPE and HC.

Gene Variants in Premature Ejaculation: Systematic Review and Future Directions

INTRODUCTION

A growing number of genetic association studies have been performed to investigate the association between the genetic susceptibility alleles and the risk of premature ejaculation (PE); however, the results remain inconclusive.

OBJECTIVES

This systematic review aimed: (i) to determine whether an association exists between gene(s) or allelic variant(s) and PE; (ii) to assess whether the associations are consistent across studies in magnitude and direction, and (iii) to identify any limitation, gap, or shortcoming in the included studies.

METHODS

The literature search was conducted in PubMed, MEDLINE, Scopus, Cochrane Library, EMBASE, Academic Search Complete, Google Scholar, and CINAHL databases.

RESULTS

Different gene variants associated with PE were assessed. 25 genetic association studies met the inclusion criteria that investigated 11 genes, 2,624 men with PE compared with 9,346 men as controls, twins, and siblings. 19 studies demonstrated a significant association with PE, whereas 4 studies denied such a relationship. SLC6A4 gene polymorphism was investigated in 11 studies (7 studies demonstrated a significant relationship with PE, and 4 studies denied such a relationship). Dopamine transporter gene (DAT1) polymorphism was investigated in 4 studies exhibiting a significant relationship. Androgen receptor gene polymorphisms were investigated in 2 studies, 1 with a significant relationship and the other with a non-significant relationship. Oxytocin gene polymorphisms and tryptophan hydroxylase 2 gene polymorphisms were investigated in 2 studies with a significant relationship.

CONCLUSION

While this review has highlighted several genes that may be potentially associated with PE such as SLC6A4, limitations such as variance in study methods, lack of robust findings, small sample sizes, lack of reproducibility, quality of reporting, and quality of assessment remain a major concern. Further efforts such as standardizing reporting, exploring complementary designs, and the use of genome-wide association studies technology are warranted to test the reproducibility of these early findings. Mostafa T, Abdel-Hamid IA, Taymour M, et al. Gene Variants in Premature Ejaculation: Systematic Review and Future Directions. Sex Med Rev 2020;8:586-602.

Regular penis-root masturbation, a novel behavioral therapy in the treatment of primary premature ejaculation

The primary premature ejaculation (PPE) is a common male sexual disorder. We proposed a novel behavioral therapy for PPE through regular penis-root masturbation (PRM). Nine heterosexual men with PPE completed the self-controlled study. After a 3-month PRM training, the median intravaginal ejaculatory latency time (IELT) increased from 60 s to 180 s (P = 0.018), and the mean Premature Ejaculation Diagnostic Tool (PEDT) score decreased from 14.8 ± 3.7 to 12.8 ± 4.1 (P = 0.074). Five out of eight patients had the prolonged dorsal nerve somatosensory evoked potential (DNSEP). The results suggest that PRM has a short-term therapeutic effect. Randomized controlled trials are needed to validate the efficacy.