Pituitary-gonadal function during sleep in men with hypoactive sexual desire and in normal controls

There is virtually no information on the psychobiology of hypoactive sexual desire (HSD) in men. This study compares pituitary and gonadal hormones and nocturnal penile tumescence (NPT) during sleep in 17 physically healthy men with HSD and 17 age-matched, nondysfunctional volunteers. There were six HSD men with problems of sexual arousal and 11 with secondary erectile impotence. The subjects, aged 27-55, were studied in a sleep laboratory for 4 nights with the last night devoted to sequential blood sampling every 20 min. The total group of HSD men had significantly lower plasma testosterone, measured hourly through the night, than controls, and there was a positive relation between testosterone and frequency of sexual behavior. There were no differences in free testosterone, prolactin, luteinizing hormone (LH), and estradiol between the HSD and control groups. The NPT parameters of HSD men with secondary impotence were consistently and significantly lower than the nondysfunctional men. These data are discussed with respect to the role of gonadal hormones in male sexual function, the significance of NPT as a window to central biologic events, and to possible heterogeneity of men with hypoactive sexual desire.     

Psychophysiologic correlates of nocturnal penile tumescence in normal males

Despite increasing clinical reliance on nocturnal penile tumescence (NPT) testing for the differential diagnosis of male impotence, little is known at present about the relationship between NPT and other aspects of sleep and waking psychophysiology. This study investigated patterns of NPT, sleep, and EEG hemispheric asymmetry in 20 male subjects, using standard polysomnographic laboratory procedures for the assessment of sleep and NPT, and a method of EEG amplitude integration developed by Goldstein. Additionally, the effects of daytime sexual activity and mood state on the duration and amplitude of NPT were studied. Overall, the results of this study confirmed the well-documented relationship between NPT and stage REM, as well as demonstrating a strong association between NPT phase and nondominant hemisphere activation. Furthermore, this association appeared to strengthen over the course of the night. Hemispheric asymmetry and stage REM were also closely linked throughout. On the other hand, no significant correlations were found between daytime sexual activity or mood state and NPT. It is suggested that concurrent assessment of hemispheric asymmetry may strengthen the diagnostic power of NPT testing in impotence cases involving central organic etiology.     

The role of oxytocin and the paraventricular nucleus in the sexual behaviour of male mammals

The paraventricular nucleus of the hypothalamus contains the cell bodies of a group of oxytocinergic neurons projecting to extrahypothalamic brain areas and to the spinal cord, which are involved in the control of erectile function and copulation. In male rats, these neurons can be activated by dopamine, excitatory amino acids, nitric oxide (NO), hexarelin analogue peptides and oxytocin itself to induce penile erection and facilitate copulation, while their inhibition by gamma-aminobutyric acid (GABA) and GABA agonists and by opioid peptides and opiate-like drugs inhibits sexual responses. The activation of paraventricular oxytocinergic neurons by dopamine, oxytocin, excitatory amino acids and hexarelin analogue peptides is apparently mediated by the activation of nitric oxide (NO) synthase. NO in turn activates, by a mechanism that is as yet unidentified, the release of oxytocin from oxytocinergic neurons in extrahypothalamic brain areas. Paraventricular oxytocinergic neurons and mechanisms similar to those reported above are also involved in the expression of penile erection in physiological contexts, namely, when penile erection is induced in the male by the presence of an inaccessible receptive female, which is considered a model for psychogenic impotence in man, as well as during copulation. These findings show that paraventricular oxytocinergic neurons projecting to extrahypothalamic brain areas and to the spinal cord and the paraventricular nucleus play an important role in the control of erectile function and male sexual behaviour in mammals.     

MMPI evaluation of erectile dysfunction: failure of organic vs. psychogenic decision rules

This study examined previously published decision rules to ascertain the empirical utility of the MMPI in discriminating between organic and psychogenic erectile dysfunction. Subjects were 41 males who were being evaluated for prosthesis implant surgery. The mean overall 1-2-3 MMPI profile revealed diffuse somatic complaints, depression, and denial. Results indicate that the MMPI failed to discriminate between organic and psychogenic subgroups. Men with psychogenic erectile dysfunction evidenced neither significantly more nor less psychopathology on the MMPI than did those with objective organic findings.     

Arteriogenic erectile impotence

Organic causes of erectile impotence, including penile arterial insufficiency, is far more frequent than previously assumed. The aim of this review (based on the literature and previous works of the author) is to define arteriogenic erectile impotence, and to describe its pathophysiological and clinical features, the diagnostic approach, differential diagnostic aspects and possible treatment of this type of impotence. Erectile impotence is inability to react to relevant sexual stimulation, with a change in pelvic and penile hemodynamics that will increase the pressure in the cavernous bodies thus enabling vaginal intromission without special precautions; as well as inability to maintain this pressure ordinarily until ejaculation occurs. Arteriogenic erectile impotence is erectile impotence caused by insufficient arterial blood supply to the cavernous bodies regardless of the arterial disease or abnormality responsible for the insufficiency. The normal mechanism of erection is not fully understood. Accumulation of blood under pressure in the cavernous body is brought about by dilation of the arteries to the cavernous spaces and closure of the drainage from the cavernous body. The drainage blockade is active and located just inside the tunica albuginea at the origin of the emissary veins. The mechanism is probably related to the smooth muscles of the cavernous body which become relaxed at the start of erection. Furthermore, passive out-flow restriction probably supporting the active closure when the cavernous body is distended. The autonomic nerves regulating the erection come from Th10-L2 and S2-S4 and pass the pelvic plexus. The target organ neurotransmitters are probably vasoactive intestinal polypeptide and catecholamines. Penile arterial insufficiency can be demonstrated by penile blood pressure measurement either as a simple measurement, or, better, as pelvic steal test and hyperemic stress test. Ultrasonic Doppler pulse curve analysis is another way of demonstrating penile arterial insufficiency. Visualization of the arterial disease causing penile arterial insufficiency requires bilateral selective internal iliac arteriography.(ABSTRACT TRUNCATED AT 400 WORDS)     

Reliability of NPT scoring and visual estimates of erectile fullness

We report the reliability of nocturnal penile tumescence (NPT) scoring and visual estimates of erectile fullness performed by a group of eight registered polysomnographic technologists (RPSGTs). We achieved overall good to excellent interrater reliability (as measured by coefficients of variation, CVs) for seven widely used electrographic measures of NPT activity: number of episodes, categorization of episodes (full or partial), total tumescence changes, tip change, base change, duration of episode, and duration of 80% maximum tumescence. In two different visual estimate trials using photographs, separated by 2 weeks, female technologists (n = 4) made mean visual estimates of erectile fullness that were significantly higher than those of male technologists (n = 4). In addition, the CVs among the female technologists on visual estimates was consistently lower than those of the males. Higher correlations, however, were found between male technologists' estimates of fullness versus buckling force than for female technologists' estimates. Thus, the gender of a technologist may affect visual estimates of erectile fullness during NPT assessment.     

Nocturnal penile tumescence in healthy 20- to 59-year-olds: a revisit

This report presents data on normative nocturnal penile tumescence (NPT), based on a study of 48 healthy men aged 20-59 years, without complaints of erectile dysfunction. In general, the current measures show good concordance with those reported by Karacan and colleagues in 1976. The effect of "pathology-free" aging (from age 20 to 59) on electrographic measures of NPT is relatively modest, accounting for 8.4-14.4% of the variance. Furthermore, no age effect on visual estimates of erectile fullness or on buckling force estimates of penile rigidity were present. Maximum buckling force and maximum erectile fullness showed stability across the four decades of the Pittsburgh sample.     

Reliability and validity of the Florida Sexual History Questionnaire

The Florida Sexual History Questionnaire (FSHQ) is a brief 20-item questionnaire designed to assess male sexual dysfunction. The validity and reliability of the scale were examined in 33 diabetic impotent males and 58 nondiabetic, age-equivalent nonimpotent males. The FSHQ was found to have high internal consistency and split-half reliability and significantly discriminated between nonimpotent and impotent subjects. Among diabetic impotent subjects, some of the test items were correlated significantly with physiological measures of sexual functioning. However, the FSHQ failed to discriminate between diabetics diagnosed as having organic or psychogenic impotence. This latter finding is discussed within the context of recent suggestions that it may not be possible to draw a clear dichotomy between organic and psychogenic impotence.     

性操作焦虑对阴茎勃起障碍的影响研究

勃起障碍 (ｅｒｅｃｔｉｌｅｄｙｓｆｕｎｃｔｉｏｎ ,简称ＥＤ)是指阴茎勃起的持续时间和 /或强度在性交中不能达到令人满意的程度 ,是夫妻性生活失败的常见原因。根据勃起障碍发生的病因学 ,分为心因性勃起障碍与混合性勃起障碍[1] 。在临床治疗中 ,由于心理性因素较器质性因素更为隐蔽的特点 ,常造成治疗者束手无策之局面。据Ｂｈｕｇｒａ(1988)统计 ,其诊所亚裔男女患者流失率分别为 5 2 .3%和 5 0 % ,西方男女患者的流失率分别为 4 7.5 %和 30 %。在笔者所在的门诊中 ,一次求诊者不下 6 0 %。心因性ＥＤ困扰个人、家庭、影响夫妻之间的…     

性别角色对心因性勃起障碍的影响研究

目的 :了解心因性ED的性别角色取向及对心因性ED患者的影响 ,增进对特定文化背景下的中国人的性心理和行为模式的理解 ,为有效的预防及制定性治疗方案提供依据。方法 :以“勃起障碍评定量表”、“Bem性别角色调查表”为研究工具 ,在临床上对 74名受试者 (30名心因性ED患者和 4 4名正常对照 )进行测试 ,测试结果直接由测试软件转移到统计软件后作统计分析。结果 :心因性ED患者更倾向于女性气质的性别认同 ,性别角色呈现女性化类型的被试在性活动中呈现出低唤起能力及低满意度。结论 :了解患者的性别角色类型及其形成过程是临床治疗中不可忽视的一个方面。     

Cardiac autonomic function during sleep in psychogenic and organic erectile dysfunction

The present study investigated the sympathetic/parasympathetic balance during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep in patients with psychogenic and organic erectile dysfunction. The cardiac autonomic balance was assessed from the power of the low frequency (LF) and high frequency (HF) spectral components of heart-rate variability in 11 patients with psychogenic erectile dysfunction and 11 patients with organic erectile dysfunction as determined by monitoring sleep-related erections. Spectral analysis of heart-rate variability was calculated for at least four successive 4-min epochs of electrocardiogram recordings during NREM sleep and for all available 4-min epochs during REM sleep. Statistical analysis revealed that organic patients had a significantly higher LF/HF ratio (P < 0.01) during both stages of sleep, which resulted from a significantly lower power in the HF component (P < 0.004) and higher power in the LF component (P < 0.01) in these patients, in both REM and NREM sleep stages. These results demonstrate that patients complaining of daytime sexual dysfunction and found by sleep-related erection monitoring to suffer from organic erectile dysfunction, have altered cardiac autonomic balance during both stages of sleep.     

Evaluation and Treatment of Patients with Impotence

Impotence is a common problem of adult males. Thorough history from both partners, physical examination, and laboratory work uncover a small minority who are suffering from an organic cause. The majority of such patients have a psychological basis for the condition. In the absence of demonstrated organic disease, psychiatric consultation is indicated. Surgery is helpful in erectile impotence.     

Erectile dysfunction and symptoms of sleep disorders

STUDY OBJECTIVES: Sleep apnea often is associated with impotence and/or erectile dysfunction (ED). The purpose of this study was to test whether a presentation for ED confers a pretest probability for obstructive sleep apnea hypopnea syndrome (OSAHS). DESIGN: A self-report survey for sleep complaints was conducted in consecutive male patients (>16 years of age) presenting to a urologic practice site. SETTING: The survey was provided to new and follow-up out-patients over a 2 month period of time. Other information collected included the presenting complaint, the clinical diagnosis for ED, and history of preexisting medical conditions. PARTICIPANTS: N/A. INTERVENTIONS: N/A. MEASUREMENTS and RESULTS: 285 males [91% of the sample: 50 years old (range 16-82) and body mass index, 27.3 (range 16.8-52.5)] completed the survey. 181 (63%) had complaints of ED; of those, 76% had a final diagnosis of organic and 8.2%, psychogenic or both psychogenic and organic ED. Of all respondents, 35.4% reported persistent snoring, 14% reported persistent waketime sleepiness or fatigue, and 26.8% were at "high risk" (Netzer et al., 1999) for OSAHS. Some were high risk for insomnia (13.6%) and restless legs syndrome or for narcolepsy (2% each). There was a correlation between those with ED complaints (p<0.014) or those with a final diagnosis of organic ED (p<0.029) and snoring. In a logistic model that included age, snoring, and preexisting conditions, only age, depression, and history of hypercholesterolemia, were found to vary significantly among those with and without ED. CONCLUSIONS: Urology patients will report a variety of sleep problems, but neither persistent snoring nor suspected OSAHS is correlated uniquely to ED.     

Effects of pinacidil on isolated human corpus cavernosum penis

Intracavernous injection of vasoactive agents causing vasodilatation is widely recognized in the diagnosis and treatment of erectile dysfunction. However, papaverine, the drug most commonly used for this purpose, may produce priapism and fibrotic lesions, and alternatives without these disadvantages are desirable. In this study we investigated the effects of pinacidil, a vasodilator drug supposed to act through the opening of K+ channels, on isolated human corpus cavernosum penis. Besides abolishing spontaneous contractile activity, pinacidil effectively relaxed preparations precontracted by noradrenaline 10(-6) M and inhibited contractions induced by electrical field stimulation of nerves. Furthermore, pinacidil depressed contractions induced by low-K+ solutions (less than or equal to 20 mM) and concentration-dependently increased the efflux of 86Rb from preloaded tissue. The results suggest that pinacidil is effective in relaxing isolated human erectile tissue, probably by way of increased K+ permeability and subsequent hyperpolarization. Clinical testing seems justified in order to find out if K(+)-channel openers can be used in the pharmacological treatment of impotence.     

Erectile dysfunction: an overview

Erectile dysfunction is a common (affecting 10-20 million menin the USA) and multifactorial disease due to organic and/orpsychological factors that strongly impairs the quality of lifein man. During the past decade many advances in the understandingof pathophysiology of erectile dysfunction have been made andnew therapeutic strategies have become available. It has beenestablished that an insufficient production of nitric oxideby penile nerve terminals and/or vascular endothelium may resultin an impaired erection or complete impotence. Nowadays, intracavernousinjection of vasoactive drugs represents a standardized approachfor the diagnosis, and the treatment of choice, for erectiledysfunction, but is not widely accepted by the patients. Thepossibility of treating erectile dysfunction with intraurethraladministration of prostaglandin-E₁ has recently become availablein the USA, and is a therapy more acceptable to the patients.Other non-invasive medical therapies are undergoing evaluation.     

Corporeal blood gas changes according to duration of drug-induced prolonged erection.

The corporeal blood gas changes in accordance with the duration of the prolonged erection which developed after intracorporeal pharmacotherapy with papaverine and phentolamine were investigated in 62 impotence patients. The picture of the corporeal blood taken from 15 psychogenic impotence patients (a control group) at 10 minutes after intracavernous injection when they showed full erections was arterial but there was pCO2 rise and pH drop compared to femoral artery blood taken simultaneously. As the erection lasted longer, significant gas changes of the cavernous blood began to appear (p < 0.0001): increase in pCO2 and decrease in pO2 from 4 hours, decrease in pH from 5 hours, decrease in O2 saturation from 6 hours. Erections lasting for more than 16 hours showed significantly worse hypoxia (p < 0.05). Therefore, to prevent hypoxia and metabolic acidosis, drug-induced prolonged erection would be better decompressed before it lasts for more than 4 hours.     

Noradrenergic innervation of the penis in control and streptozotocin-diabetic rats: evidence of autonomic neuropathy

The noradrenergic sympathetic innervation of the penis of control and 4-month streptozotocin-diabetic rats was examined with the glyoxylic acid histofluorescence method. Noradrenergic varicosities were found in the corpora cavernosa in a dense subtunical plexus and in the perisinusoidal and trabecular regions of the erectile tissue, in the corpus spongiosum in perisinusoidal tissue, around large arteries and veins, and around small tortuous arterioles and small draining veins of the corpora cavernosa and spongiosum. Noradrenergic varicosities were diminished in number and fluorescent intensity in all regions of the penis of diabetic rats compared with controls. The subtunical plexus was absent, perisinusoidal and trabecular varicosities were sparse, and only occasional intermittent, discontinuous, dull fluorescent fibers or plexuses were found around the vessels. Quantitation with high-performance liquid chromatography revealed a significant reduction of norepinephrine in the penis of diabetic rats compared with controls. The present study suggests that long-term streptozotocin diabetes in the rat is accompanied by sympathetic autonomic neuropathy of the penis that seems to parallel changes in the noradrenergic content of penile corpora of men with diabetes and erectile impotence. The streptozotocin-diabetic rat merits further study to explore the relationship between noradrenergic innervation of the penis and erectile tissue.     

Diabetes, erectile dysfunction, and sleep-related erections

Sleep-related erections were assessed in conjunction with polysomnography in 100 diabetic and 400 nondiabetic men with complaints of erectile problems. We also measured bulbocavernosus reflex latency, heart rate response to deep breathing, postural-related blood pressure changes, penile arterial sufficiency, and brachial blood pressures. To investigate the relationship between diabetes and erectile capacity, the results obtained from men with and without diabetes were compared. Men with diabetes had fewer sleep-related erections, less tumescence time, diminished penile circumference increase, and lower penile rigidity than nondiabetic men. These diabetes-related differences were found regardless of the maximum penile rigidity observed. The diabetic group had less heart rate response to deep breathing and lower penile blood pressures than the nondiabetic group, but only among men with maximum penile rigidity less than 500 g. These data indicate that both neurological and vascular mechanisms are involved to a greater degree in organic diabetic impotence than in the organic erectile dysfunction that occurs in nondiabetic men. Finally, the pattern of lower values for measures of nocturnal tumescence among diabetic men, compared to nondiabetic men, occurred in all age groups, except the oldest. Among impotent men, age 65 years or older, no difference was found between men with and without diabetes. This suggests that diabetes may foreshadow some of the age-related pathophysiological processes associated with erectile dysfunction.     

Intracavernous prostaglandin E1 in erectile dysfunction

Summary Prostaglandin E1 (PGE₁) is a naturally occurring substance that is present in a variety of mammalian tissues, including the semen of fertile men. Its use in the diagnosis and treatment of erectile dysfunction has been extensively studied. In doses of 10–20 g, PGE₁ produces full erections in 70–80% of patients with erectile dysfunction. In diagnostic use PGE₁ is employed as a simple office test and in conjunction with various hemodynamic tests. Self-injection of PGE₁, either with the patient or his partner administering the injection, is a minimally invasive and effective treatment for erectile dysfunction in patients with organic or psychogenic erectile dysfunction. Its use is contraindicated in patients with sickle cell anemia, severe coagulopathy, schizophrenia or severe psychiatric disorder, poor manual dexterity, severe venous incompetence, or severe systemic disease. As calculated from data in the published literature, the most frequent side effects are pain at the injection site or during erection (occurring in 16.8% of patients), hematoma/ecchymosis (1.5% of patients), and prolonged erection/priapism (1.3% of patients). The potential for prolonged erection/priapism, the most serious side effect, can be minimized by careful titration of the dose and through patient education. Systemic side effects occur rarely during PGE₁ use. During extended use, patients should be monitored for potential long-term side effects, such as fibrosis and angulation.Abbreviations ED erectile dysfunction - PGE₁ prostaglan-din E₁     

Stresses in the normal and diabetic human penis following implantation of an inflatable prosthesis

The prevalence of impotence in diabetes mellitus ranges as high as 75%. The implantation of an inflatable penile prosthesis (IPP) is frequently carried out to restore erectile function. However, clinical studies have demonstrated that severe post-implantation penile pain during erection is a common complication in diabetic men. A biomechanical model of the penis/prosthesis complex is developed, based on cross-sectional anatomy, to simulate the internal stress distribution due to interaction of the prosthesis with both normal and diabetic penile tissues. The material properties of the model components are adopted from experimental data. The model is solved by using commercial finite-element software for a characteristic inflation loading of the penile prosthesis. Elevated structural stresses during erection are found in the dorsal aspect of the tunica albuginea (normal 5.1-31.5 kPa, diabetic 5.1-70 kPa post-implantation). Following IPP implantation, stresses in the diabetic penis are almost as twice as high as those in the normal one and can cause a painful sensation owing to nerve stimulation or to ischaemia in regions of compressed vascular tissue.