Oxytocin (OT) is a female hormone with the main function of facilitating uterine contraction and milk ejection. Recent studies show that OT is involved in multiple signaling pathways in the central and peripheral nerve system and mainly regulates the physiology and activity of reproduction, including male reproduction and sexual behavior. The roles of OT in penile erection are bio-phasic with proerectile effect in the central nerve system while peripherally inhibiting erection. OT also mediates ejaculation, post-ejaculatory detumescence and the post-orgasm refractory period. OT and OT-receptor in the central nerve system will be a new target in the drug development for the treatment of erectile dysfunction, while OT intracavernous injection promises to be an effective therapy for priapism. This review focuses on the effects of OT on male sexual activities.
Humans ; Male ; Oxytocin ; physiology ; Penile Erection ; Sexual Behavior

Studies on nocturnal penile tumescence characteristics in normal men have advantages of further investigations of erection physiology and of impotence research. We conducted a study of nocturnal penile tumescence in 30 Korean healthy males aged 21 to 68 (divided into 5 groups, from 20s to 60s) by means of polysomnographic monitoring to provide normative data on how it is related to man`s sexual function with aging and its range of characteristics for the management of impotence. Analyses of 60 sleep data showed that with aging from 20s to 60s, there was steady decrease in mean values of total tumescence time, total tumescence time/total sleep period time, total tumescence time/total REM period time, amount of maximum REM-related tumescence episodes, frequency of REM-related tumescence, frequency of maximum REM-related tumescence episode, as well as of penile circumferential change and penile rigidity in maximum tumescence episode. These results indicate that there is steady decrease in the quality of nocturnal penile tumescence including frequency, duration, amount and degree with aging from 20s to 60s, which reflects changes of sexual capacity and function in psychosexul aspect. We suppose these normative data will contribute to further clinical investigations of nocturnal penile tumescence and male sexual dysfunction.
Adult* ; Aging* ; Erectile Dysfunction ; Humans ; Male ; Penile Erection* ; Physiology

Erectile dysfunction (ED) results from the interaction of many pathological factors. Studies show that a high incidence of ED is associated with chronic diseases of various systems, and its pathogenesis is not fully understood. This article outlines the progress in recent studies on the impact of chronic diseases on erectile function.
Chronic Disease ; Erectile Dysfunction ; etiology ; Humans ; Male ; Penile Erection ; physiology

OBJECTIVETo evaluate the effect of circumcision on the glans penis sensitivity by comparing the changes of the glans penis vibrotactile threshold between normal men and patients with simple redundant prepuce and among the patients before and after the operation.

METHODSThe vibrotactile thresholds were measured at the forefinger and glans penis in 73 normal volunteer controls and 96 patients with simple redundant prepuce before and after circumcision by biological vibration measurement instrument, and the changes in the perception sensitivity of the body surface were analyzed.

RESULTSThe G/F (glans/finger) indexes in the control and the test group were respectively 2.39 +/- 1.72 and 1.97 +/- 0.71, with no significant difference in between (P > 0.05). And those of the test group were 1.97 +/- 0.71, 2.64 +/- 1.38, 3.09 +/-1.46 and 2.97 +/- 1.20 respectively before and 1, 2 and 3 months after circumcision, with significant difference between pre- and post-operation (P < 0.05).

CONCLUSIONThere is a statistic difference in the glans penis vibration perception threshold between normal men and patients with simple redundant prepuce. The glans penis perception sensitivity decreases after circumcision.

Adult ; Circumcision, Male ; Humans ; Male ; Penile Erection ; physiology ; Sensory Thresholds

In contrast to the spinal control of erection, relatively little is known about the brain control. In the present review, we have outlined the role of brain structures involved in penile erection and provided a synopsis on the brain circuit of erection. Findings from both animal and human studies are discussed. Evidence suggests that the most important structures are the frontal lobe, cingulate gyrus, amygdala, thalamus and hypothalamus. Within the brain circuit of erection, the thalamus serves as a gate-controller in which all relevant information is evaluated and further processed to higher and lower centres.
Brain ; physiology ; Humans ; Male ; Models, Neurological ; Nerve Net ; Penile Erection ; Thalamus ; physiology

OBJECTIVETo explore the relationship between aging and erectile function changes in rats in order to establish a rat model of aging-related erectile dysfunction (ED).

METHODSEighty male Wistar rats were equally divided into four age groups (3-, 6-, 12- and 18-month) and treated with intragastric administration of sildenafil citrate (Sn) for penile erection tests. Twenty 3-month-old female Wistar rats were randomized to four groups as oestrous rat models. We recorded the rate and frequency of penile erections of the male rats in different age groups.

RESULTSThe rates of penile erection were 85%, 75%, 40% and 30% and erectile frequencies were 2.27 +/- 0.80, 2.00 +/- 0.61, 1.40 +/- 0.51 and 1.29 +/- 0.49 in the 3-, 6-, 12- and 18-month rats, respectively, with statistically significant differences among different age groups (P < 0.01). And their erectile function exhibited a tendency to decrease with the increase of age. Besides, comparison of the 3-month with the 6-, 12- and 18-month groups showed significantly reduced erectile function in the 18-month rats (P < 0.05) but no remarkable difference between the 3-month and the 6- and 12-month groups (P > 0.05).

CONCLUSIONAging is one of the main risk factors of rat erectile dysfunction, and 18-month-old male rats are qualified for the establishment of the rat model of aging-related erectile dysfunction.

Aging ; physiology ; Animals ; Erectile Dysfunction ; physiopathology ; Male ; Models, Animal ; Penile Erection ; physiology ; Rats ; Rats, Wistar

OBJECTIVESTo evaluate modified cystectomy with preservation of erectile and ejaculatory functions in men with nonmalignant bladder disease.

METHODSSeven cases with average age of 27 years presented with bladder disease necessitating cystectomy, including 2 cases of tuberculous contractile bladder, 1 case of extensive polypoid cystitis glandularis, 4 cases of late stage of neurogenic bladder. All patients wished to maintain erectile and ejaculatory functions after the operation. We performed a modified simple cystectomy with preservation of the vasa deferens, seminal vesicles, prostate and neurovascular bundles, as well as construction of an Indiana pouch or ileal neobladder.

RESULTSAverage operative time was 5 h 45 min without perioperative complications in this group. Follow-up ranged from 9 to 60 months. Erectile and ejaculatory functions were normal in all cases. All patients remained completely continent and no dysuria in neobladder, and there was no difficulty in inserting catheter to empty pouch. Upper urinary tract was in good condition 3 and 24 months after operation.

CONCLUSIONSModified cystectomy with preservation of the vasa deferens, seminal vesicles, prostate and neurovascular bundles is an effective and reliable option for the patients who wish to maintain their fertility and erectile function after surgery.

Adult ; Cystectomy ; methods ; Ejaculation ; physiology ; Humans ; Male ; Middle Aged ; Penile Erection ; physiology ; Urinary Bladder Diseases ; surgery

Humans ; Male ; Parkinson Disease ; physiopathology ; Penile Erection ; physiology ; Receptors, Dopamine ; physiology ; Spinal Cord ; physiology ; physiopathology ; Urinary Bladder ; physiology

Prolactin is a polypeptide hormone which mainly acts on the reproductive system and plays an important role in penile erection and ejaculation. Prolactin receptors have a variety of short forms apart from the classic long form, which are widely expressed in male reproductive glands. High levels of prolactin can induce erectile dysfunction and results in secondary male infertility, which are mainly associated with the inhibition of dopaminergic activity, reduction of the testosterone level, and contraction of the cavernous smooth muscle. Moreover, low levels of prolactin can result in ejaculatory dysfunction. This article updates the views on the expressions of prolactin receptors in the male reproductive system, the effects of prolactin on penile erection and ejaculation, and its action mechanisms.
Ejaculation ; physiology ; Erectile Dysfunction ; Humans ; Infertility, Male ; Male ; Muscle, Smooth ; physiopathology ; Penile Erection ; physiology ; Prolactin ; physiology ; Receptors, Prolactin ; physiology ; Reproduction

OBJECTIVETo investigate the efficacy of tadalafil on nocturnal penile tumescence (NPT).

METHODSThirty-four patients with organic erectile dysfunction (ED) were treated with oral tadalafil at the dose of 10 mg/3 d before bedtime. A month later, 14 of the patients were observed for NPT by nocturnal electrobioimpedance volumetric assessment (NEVA).

RESULTSThe parameters of erectile function significantly improved in the 14 patients (P < 0.05).

CONCLUSIONOral administration of minute dose of tadalafil can improve NPT in organic ED patients.

Adult ; Carbolines ; administration & dosage ; therapeutic use ; Erectile Dysfunction ; drug therapy ; Humans ; Male ; Penile Erection ; physiology ; Tadalafil