Premature ejaculation (PE) is the most common male sexual dysfunction, which represents a diagnostic as well as a therapeutic challenge for physicians. However, no universally accepted definition is currently available for PE. As a result, physicians continue to diagnose patients with PE according to major guidelines set by the professional societies. These guidelines either recommend the use of validated questionnaires or patient-reported outcomes. Recent efforts directed toward classifying PE may help provide a better understanding of the prevalence and risk factors of this disorder. While the exact etiology of PE has not been clearly elucidated, several risk factors have been strongly reported in the literature. Clearly, to understand the revised definition of PE, its etiology and pathophysiology is necessary to improve the clinical management of this medical condition and form the basis of future research in this regard. In this review, we highlight the past and current definitions of PE and present an appraisal on the classifications and theories suggested for the etiopathogenesis of PE.
Humans ; Male ; Premature Ejaculation/physiopathology*

Premature ejaculation (PE) is a commonest male sexual dysfunction clinically, with a complex pathogenesis and unsatisfactory treatment results. To clarify the etiology of PE is essential for the improvement of the therapeutic effect, and the animal model is an important tool for investigating its pathogenesis and treatment protocols. Currently there are various animal models for this purpose, each with its own characteristics and some suitable for animal experiments only. The application value of an animal model of PE depends on its repeatability, efficiency, and ability of fully simulating the clinical features of humans. This paper presents an overview on the most commonly used animal models of PE, compares their advantages and disadvantages, and provides some evidence for choosing the most suitable ones for PE studies.
Animals ; Disease Models, Animal ; Humans ; Male ; Premature Ejaculation ; physiopathology

Although premature ejaculation (PE) is a common type of male sexual dysfunction, to date we lack a unified definition of PE. The multidimensional definition of PE has been accepted by more and more clinicians. Intravaginal ejaculatory latency time (IELT) is one of the three important dimensions (time to ejaculation, inability to control or delay ejaculation, and negative consequences) for defining PE. Rapid ejaculation is one of the core symptoms of PE and IELT is an objective measurement as well as an important tool for the evaluation of PE. This article reviews estimated IELT, stopwatch-measured IELT, the correlation between estimated and stopwatch-measured IELT, and the factors affecting IELT in the general male population, PE patients, and those complaining of PE.
Coitus ; Ejaculation ; physiology ; Humans ; Male ; Premature Ejaculation ; etiology ; physiopathology ; Reaction Time ; physiology ; Time Factors

Premature ejaculation (PE) is a most common male sexual dysfunction with complex pathogenesis. An increasing number of scholars agree that PE is a disorder associated with abnormal neurobiology, which involves the central neurotransmitter system, peripheral nerve function of the nerve tissue structure, and neurological biochemistry. This review focuses on the neurobiological mechanisms of PE, expecting to gain a deeper insight into the possible etiology, objective and reliable diagnostic methods, and individualized treatment of the disease.
Biochemical Phenomena ; Ejaculation ; Humans ; Male ; Neurotransmitter Agents ; physiology ; Peripheral Nervous System ; physiopathology ; Premature Ejaculation ; etiology

ObjectiveTo investigate the feasibility and practicability of establishing an animal model of primary premature ejaculation using the ejaculation distribution theory.

METHODSWe induced behavioral estrus in 32 ovariectomized female SD rats by subcutaneous injection of 20 μg estradiol benzoate at 48 hours and 500 μg progesterone at 4 hours before mating them with 49 male rats once a week for six times. During the last three opulations, we observed the male animals for mounting latency (ML), intromission latency (IL), ejaculation latency (EL), postejaculation interval (PEI), mounting frequency (MF), intromission frequency (IF), intromission rate (IR), and ejaculation frequency (EF).

RESULTSFinally, 22 of the male rats were included in this study. The mean EF>33 was deemed rapid ejaculation,EF<1 sluggish ejaculation, and EF 1.5－2.5 normal ejaculation. The EL was significantly shorter in the rapid ejaculation group than in the sluggish and normal ejaculation groups. The IF was the lowest in those with rapid ejaculation. No statistically significant differences were observed in the ML among the three groups of rats.

CONCLUSIONSBased on the mean ejaculation frequency, the male rats with rapid ejaculation were easily screened, and this animal model may play an important role in exploring the mechanisms of primary premature ejaculation.

Animals ; Disease Models, Animal ; Ejaculation ; Female ; Male ; Premature Ejaculation ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Sexual Behavior, Animal

This study aimed to investigate perceived ejaculatory function/satisfaction before treatment for lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) and to identify associations between specific categories of ejaculatory dysfunctions (EjDs) and LUTS. A total of 1574 treatment-naïve men with LUTS/BPH were included in this study. All patients underwent routine evaluation for LUTS/BPH including the International Index of Erectile Function and a 5-item questionnaire developed to assess ejaculatory volume/force/pain/satisfaction/latency time. Patients who had sexual intercourse over the past 4 weeks were classified as sexually active group. A total of 783 patients were categorized as sexually active group. Decreased ejaculatory volume and force were reported by 53.4% and 55.7% of 783 sexually active men, respectively. There was a strong correlation between ejaculatory volume and force. Ejaculatory pain/discomfort, premature ejaculation (PE), and delayed ejaculation (DE) were reported in 41.0%, 16.3%, and 41.4% of the patients, respectively. Over 40.0% of men without decreased ejaculation volume/force were satisfied with ejaculatory function, whereas approximately 6.0% of men with decreased volume/force were satisfied with ejaculatory function. About 30.0% of men with decreased volume/force had orgasmic dysfunction, while approximately 10.0% of men without decreased volume/force did. Decreased ejaculatory volume or force was associated with LUTS severity after adjusting for other influential factors including testosterone level, erectile function, and prostate size on ultrasonography, but PE or DE or ejaculatory pain/discomfort was not. In conclusion, a considerable portion of men with LUTS/BPH appear to have a variety of EjDs. Ejaculatory volume/force and satisfaction/orgasm do not always appear to be concordant. Ejaculatory volume or force is independently associated with LUTS severity, whereas PE or DE or ejaculatory pain/discomfort is not.
Aged ; Coitus ; Ejaculation ; Humans ; Lower Urinary Tract Symptoms/physiopathology* ; Male ; Middle Aged ; Orgasm ; Pain/etiology* ; Personal Satisfaction ; Premature Ejaculation/physiopathology* ; Prostate/diagnostic imaging* ; Prostatic Hyperplasia/physiopathology* ; Sexual Dysfunction, Physiological/physiopathology* ; Surveys and Questionnaires ; Testosterone/blood*

The nerve electrophysiological tests may differentiate the treatment of primary premature ejaculation (PPE) in our previous studies. However, no study verifies if the results will be affected by abstinence time. From January to December in 2016, fifty PPE patients ejaculated within 2 min and 28 control subjects were enrolled. The nerve electrophysiological tests, including dorsal nerve somatosensory evoked potential (DNSEP), glans penis somatosensory evoked potential (GPSEP), and penile sympathetic skin response (PSSR), were recorded before and immediately after ejaculation. The abstinence day was not correlated with the latencies of SEPs or PSSR neither in PE group (P = 0.170, 0.064, and 0.122, respectively) nor in control group (P = 0.996, 0.475, and 0.904, respectively). No statistically differences were found in the latencies of SEPs and PSSR before and after ejaculation in PE patients (P = 0.439, 0.537, and 0.576, respectively) or control subjects (P = 0.102, 0.198, and 0.363, respectively). Thus, abstinence time does not interfere with the nerve electrophysiological test, which is stable in determining the nerve function of PPE patients.
Adult ; Ejaculation ; Electric Stimulation ; Electrophysiological Phenomena ; Evoked Potentials, Somatosensory ; Humans ; Male ; Middle Aged ; Penis/physiopathology* ; Premature Ejaculation/physiopathology* ; Prospective Studies ; Sexual Abstinence ; Skin/innervation* ; Sympathetic Nervous System/physiopathology* ; Young Adult

Penile hypersensitivity plays an important role in premature ejaculation (PE), but differences in penile sensitivity among subtypes of PE are unknown. Therefore, we compared penile sensory thresholds in PE subtypes of lifelong and acquired PE, PE with and without erectile dysfunction (ED), PE with an intravaginal ejaculation latency time ≤1 min and >1 min, and PE with and without orgasmic pleasure perceptual dysfunction. During August 2014 to January 2016, 136 patients with PE were included. Penile warm, cold, and vibratory thresholds were measured. Data of clinical characteristics, sexual life, Premature Ejaculation Diagnostic Tool (PEDT) score, and the 5-item version of the International Index of Erectile Function (IIEF-5) score were collected. Vibratory thresholds of the PE with ED group were higher in the right coronal sulcus (median amplitude: 4.92 vs 3.65 μ m, P = 0.02) and the right penile shaft (median amplitude: 3.87 vs 3.30 μ m, P = 0.03), while differences in penile sensory thresholds between other subtypes were not significant. The median PEDT score was lower in the PE without ED group (12 vs 14, P < 0.001). The IIEF-5 and PEDT scores were negatively correlated (r = -0.29, P < 0.001). Patients with orgasmic pleasure perceptual dysfunction had a lower median IIEF-5 score (20 vs 21, P = 0.02). Patients with PE and ED had lower penile sensitivity, and ED was associated with more severe symptoms and weaker orgasmic pleasure perception. In men with PE, management of comorbid ED is necessary. In case of side effects in erectile function, topical anesthetics should be cautiously used in men with PE and ED.
Adolescent ; Adult ; Ejaculation ; Erectile Dysfunction/physiopathology* ; Humans ; Male ; Middle Aged ; Orgasm ; Penis/physiology* ; Physical Stimulation ; Pleasure ; Premature Ejaculation/physiopathology* ; Prospective Studies ; Sensory Thresholds ; Sexual Dysfunctions, Psychological ; Sexuality ; Surveys and Questionnaires ; Temperature ; Vibration ; Young Adult

ObjectiveTo investigate the correlation between the premature ejaculation diagnostic tool (PEDT) and International Index of Erectile Function-15 (IIEF-15) in different types of premature ejaculation (PE).

METHODSWe performed a cross-section survey among 352 PE patients received in the andrology clinic from December 2014 to December 2015 and 104 healthy men from the health examination center using basic demographic information (as on age, height, weight, education status, occupation, income, etc.), PEDT results, and IIEF-15 scores of the subjects.

RESULTSThe PE patients had remarkably higher PEDT and lower IIEF-15 scores than the healthy men (P<0.01). The PEDT score of the PE patients was negatively correlated with their total IIEF-15 score as well as with the scores in the domains of erectile function, sexual intercourse satisfaction, and overall satisfaction after adjusted for age (P<0.01). The patients with acquired PE (APE) showed a lower IIEF-15 score than those with lifelong PE (LPE) (P<0.01). The PEDT score of the APE patients was correlated negatively with the total IIEF-15 score (r=－0.391, P<0.01) and the scores in the domains of erectile function (r=－0.362, P<0.01) and overall satisfaction (r=－0.621, P<0.01), but not correlated with intercourse satisfaction, sexual orgasm, or sexual desire. The PEDT score of the LPE group was correlated negatively with intercourse satisfaction (r=－0.286, P<0.05) but not correlated with either the total IIEF-15 score or the scores in the domains of erectile function, overall satisfaction, sexual orgasm, or sexual desire.

CONCLUSIONSPE patients have a higher PEDT score and a lower IIEF-15 score than normal males. The PEDT score of APE patients is significantly correlated with the total IIEF-15 score, while that of LPE patients is correlated not with the total IIEF-15 score but with intercourse satisfaction.

Adult ; Andrology ; Case-Control Studies ; Coitus ; psychology ; Cross-Sectional Studies ; Erectile Dysfunction ; physiopathology ; Humans ; Libido ; Male ; Middle Aged ; Penile Erection ; physiology ; Personal Satisfaction ; Premature Ejaculation ; diagnosis ; physiopathology ; Surveys and Questionnaires

Objective: To explore the feasibility and practicability of establishing a rat model of premature ejaculation (PE) by injection of 8-OH-DPAT into the subarachnoid space of the lumbosacral spinal cord segments. METHODS: Twenty-four male Wistar rats were equally randomized into a PE model and a blank control group. The PE model was established by injection of 8-OH-DPAT in 10 ml normal saline at 0.8 mg per kg of the body weight per day into the subarachnoid space of the lumbosacral spinal cord segments and the control rats were injected with the same volume of normal saline only, both for 4 weeks. Another 24 female Wistar rats were injected subcutaneously with benzoic acid estradiol at 20 μg to induce estrus at 36 hours before mated with the male animals. At 2 and 4 weeks, the male rats were mated with the female ones for 30 minutes each time and meanwhile observed for their mating behavior indicators, such as mount latency, intromission latency, ejaculation latency, mount frequency, intromission frequency, and ejaculation frequency. RESULTS: Compared with the controls, the PE model rats showed a significantly lower ejaculation latency (［712.35 ± 36.77］ vs ［502.35 ± 46.72］ s, P<0.05), mount latency (［11.22 ± 3.60］ vs ［8.69 ± 2.48］ s, P<0.05), mount frequency (13.28 ± 0.24 vs 7.53 ± 1.84, P<0.05), and intromission latency (［22.33 ± 2.45］ vs ［12.08 ± 1.39］ s, P<0.05), but a remarkably higher ejaculation frequency (2.01 ± 0.48 vs 4.26 ± 0.89, P<0.05). No statistically significant difference was observed between the control and model animals in the intromission frequency (7.49 ± 2.21 vs 6.45 ± 1.89, P>0.05). CONCLUSIONS A rat model of premature ejaculation was successfully established by injection of 8-OH-DPAT into the subarachnoid space of the lumbosacral spinal cord segments, which is of great significance for further study of the mechanism of premature ejaculation.
8-Hydroxy-2-(di-n-propylamino)tetralin ; administration & dosage ; Animals ; Benzoic Acid ; administration & dosage ; Disease Models, Animal ; Ejaculation ; Estradiol ; administration & dosage ; Estrus ; Feasibility Studies ; Female ; Injections, Spinal ; Male ; Premature Ejaculation ; chemically induced ; physiopathology ; Rats ; Rats, Wistar ; Sexual Behavior, Animal ; Spinal Cord ; Subarachnoid Space