Erectile dysfunction in general medicine practice: prevalence and clinical correlates

Erectile dysfunction (ED) is a common problem in general medical practice affecting especially the elderly and those with cardiovascular disease and diabetes mellitus. A study was undertaken by questionnaire distributed to consecutive adult male attendees at 62 general medical practices. 1240 completed questionnaires were available for analysis. The mean age of participants was 56.4y (range 18-91 y). 488 men (39.4%) reported ED: 119 (9.6%) 'occasionally', 110 (8.9%) 'often', and 231 (18.6%) 'all the time' (complete ED). Among 707 men aged 40-69y 240 (33.9%) reported ED and 84 (11.9%) had complete ED. The prevalence of complete ED increased with age, rising from 2.0% in the 40-49 y age group to 44.9% in the 70-79 y age group. Only 11.6% of men with ED had received treatment. Hypertension, ischaemic heart disease, peripheral vascular disease and diabetes mellitus were frequently associated with ED. 40% of diabetic men aged 60 y or older had ED all the time.

Penile fibrosis in intracavernosal prostaglandin E1 injection therapy for erectile dysfunction

Penile fibrosis (PF) may be a complication of intracavernosal injection therapy (ICI). It has been well documented as a side effect of papaverine, but there have been few reports associating penile fibrosis with prostaglandin E1 (PGE1, Alprostadil). Many authors did not find fibrotic changes in the penis while others reported penile fibrosis as a complication of intracavernosal PGE1 in only 0.76-2.1% of their patients. Recent studies, however, suggest that the incidence may be as high as 15%. Three hundred consecutive patients who returned to our Institute for repeat prescription of PGE1 were asked about penile curvature and deformity and the penis was examined for fibrotic change. Twenty-two were excluded because of concurrent or previous use of papaverine and/or phentolamine, 30 patients had pre-ICI evidence of fibrotic change and 3 had incomplete data. Of the remaining 245 patients, 57 (23.3%) were found to have penile fibrosis. These men, mean age 62 y (21-79), had been self injecting an average of 5.2 times per month (1-16) for an average period of 29.2 months (2-86). The mean dose of PGE1 used was 13 micrograms (2-60) and an average of 65.6 micrograms of PGE1 (3-360) was used per month. The mean total number of injections was 142.4 (8-810) and the mean total amount of PGE1 1703 micrograms (105-11,520). Penile fibrosis is hence a significant complication of intracavernosal PGE1 therapy. It is mandatory to examine patients methodically for fibrotic changes in the penis prior to commencement of treatment and at subsequent regular reviews. Patients should be specifically warned of the possibility of penile fibrosis and should be instructed on self examination so that they may report early changes if and when these occur.

The use of the vacuum erection device in the management of erectile impotence

A retrospective survey was conducted to assess the use, efficacy and acceptance of the Vacuum Erection Device (VED) among 60 impotent men not satisfied with intracavernosal injection therapy. Forty three (72%) men filled out the questionnaires. Thirty nine (81%) of the men abandoned the device, the main reason being that 'it did not work'. One possible explanation for this was patient selection, testing the VED on men who had previously found injection therapy unsatisfactory. Patients' attitudes to the device were unfavourable overall. Sixty four percent of men had at least one minor side effect using the VED, the most common being discomfort. The role of the partner for men using this form of treatment is unresolved. In this study, the VED was no more effective than injections in overcoming erectile dysfunction, but the relative advantages of either treatment needs to be addressed in controlled clinical trials.

A study in patients with erectile dysfunction comparing different formulations of prostaglandin E1. Alprostadil Study Group

PURPOSE

Prostaglandin E1 sterile powder and sterile solution are 2 new formulations of exogenous prostaglandin E1 that are more convenient for auto-injection therapy for erectile dysfunction than the presently used pediatric sterile solution. Therefore, the pharmacodynamic profiles of intracavernous prostaglandin E1 sterile powder and nonalcohol sterile solution were compared with the pediatric sterile solution in men with erectile dysfunction who were known to be stable responders to intracavernous prostaglandin E1.

MATERIALS AND METHODS

Based on the dose used at home, patients were randomized to 1 of 5 dose groups: 0 microgram. (placebo), 2.5 micrograms., 5 micrograms., 10 micrograms. or 20 micrograms. Each patient received a single injection of the same dose of each of the 3 formulations. The primary pharmacodynamic end points were clinical evaluation of erectile response, RigiScan real-time evaluation of erectile response and patient evaluation of erectile response.

RESULTS

No significant differences were identified among the formulations for any of these end points, either by comparison among all active doses or by comparison at each prostaglandin E1 dose level. There was also little or no intra-patient variation in dose response and the inter-dose variation in response between patients was not significant. Pharmacodynamic end points were well intercorrelated, although assessment of erectile response by the patients tended to be more positive than that by RigiScan or clinical evaluation. There were no major side effects. Penile pain on injection and/or during erection occurred in 9 to 17% of the patients according to the formulations. However, penile pain was also reported by 11% of the placebo-treated patients. CONCLUSIONS;: The 3 formulations of prostaglandin E1 showed equivalence and were safe for the treatment of erectile dysfunction with respect to side effects.

Does compression of the base of the penis improve the efficacy of intracavernosal injection of prostaglandin E1 for impotence? A randomized controlled study

The objective of this study was to evaluate the effect on erections of impeding venous blood flow following intracavernosal injections of prostaglandin E1. Dispersion of injected X-ray contrast medium indicated that application of the RMRI penile clamp to the base of the penis retarded venous outflow. The clamp was then tested in impotent men to determine whether their erectile response was enhanced. Erectile response was assessed using a Rigiscan monitor, palpation of the penis by a staff nurse and the patient's subjective impression. The results demonstrate that there is no significant improvement in erectile response following venous compression.

193-nm excimer laser sclerostomy using a modified open mask delivery system in rhesus monkeys with experimental glaucoma

Excimer laser sclerostomy is a new glaucoma filtration procedure in which the argon fluoride excimer laser at 193 nm is delivered ab externo through a modified open mask system incorporating an en-face air jet to dry the target area and preserve hemostasis during ablation and a conjunctival plication mechanism, which allows the conjunctival and scleral wounds created by through-and-through ablation to separate once the mask is removed. No preparatory dissection of the conjunctiva is required. Five 200-microns and five 500-microns sclerostomies were formed by ablation at a pulse repetition rate of 20 Hz and a fluence per pulse of 400 mJ/cm2 in fellow eyes of five rhesus monkeys with experimental glaucoma. Overall, seven of the ten eyes attained a functional result, with intraocular pressures remaining below 21 mmHg for 6 +/- 1 days and rising to the pre-operative level after 10 +/- 3 days without adjunctive antifibroblast medication. The duration of filtration for 200-microns and 500-microns sclerostomies was similar, and parallels that previously observed for posterior lip sclerectomy in the same animal model. The three eyes with no functional result all had incorrectly positioned sclerostomies. Choroidal detachment and significant shallowing of the anterior chamber did not occur. Excimer laser sclerostomy appears to be a viable technique for filtration, provided that mask placement is accurate.

Alcohol burns in the neonate

The case histories of two infants who sustained chemical burns due to contact with alcoholic skin preparation solutions are presented. The skin permeability of the extremely low birthweight infant renders them susceptible to major burns following relatively brief exposure to such solutions. Care is needed in the selection and use of skin disinfection solutions in the neonatal nursery.

The role of intracavernosal vasoactive agents to overcome impotence due to spinal cord injury

Twenty-two spinal cord injured men (mean age 35.2 years) referred because of impotence were treated with intracavernosal vasoactive agents. Papaverine 2-20 mg, papaverine 40 mg plus phentolamine 0.5 mg or prostaglandin E1 (1-20 micrograms) were used. Nineteen responded and were taught to self administer the medication with varying degrees of assistance from their partners. Fourteen men participated in a postal survey; 12 (86%) continued to use the drugs every 1 to 4 weeks and reported satisfaction with the method. Partner responses were positive in half of the group and when not so it influenced the patients to abandon or reduce the frequency of treatment. Counselling was essential to allay anxiety. Clinical management was not compromised and side effects were minimal. Overall we found this treatment effective, safe and worthwhile.

Late effects of childhood malignancies seen in Western Australia

Eighty-nine pediatric oncology patients, in remission and off treatment for at least 4 years, were reviewed annually in the Late Effects Clinic of Princess Margaret Hospital for Children in Perth, Western Australia. Interval from time of diagnosis to follow-up ranged from 4 to 23 years (mean 10.8 years). Acute lymphoblastic leukemia (ALL) (40%) and Wilms' tumor (27%) were the most common primary malignancies in this group. Late sequelae included musculoskeletal abnormalities (23 children), growth hormone deficiency (11), second tumors (9), learning difficulties (7), puberty and fertility problems (4), and hypothyroidism (4). These complications were most often related to radiation therapy. The need for prolonged, regular follow-up of survivors of childhood malignancy for early detection of late sequelae and subsequent intervention is stressed.

Effects of a sclerosant, ethanolamine, on the venous drainage system of the dog penis

To explore the possibility of using venous sclerosant therapy to overcome venogenic impotence we studied the effects of ethanolamine on the veins draining the dog penis. Following injection of the sclerosant into the deep dorsal vein radiological and histological evidence of occlusion was obtained but by one month recanalization of thrombi had occurred and collateral venous channels had formed. These findings cast doubt on the effectiveness of this sclerosant as a means of treating impotence.

The male menopause. Fact or fancy?

Men over 50 may experience a decline in sexual, physical and intellectual potency. In many respects this is analogous to the menopause, hence the term male menopause. Although this term suggests profound hormonal changes and loss of reproductive capacity these do not occur in men. The hormonal changes are subtle and loss of fertility is relative. Other changes, part of normal ageing, include degeneration of neural tissue, arterial occlusion and loss of tissue turgor.

Effects of acute alcohol on penile tumescence in normal young men and dogs

To determine the cause of the inhibition of sexual function observed in normal subjects with elevated blood alcohol concentrations (BAC), nocturnal penile tumescence (NPT) was monitored in 11 subjects over three consecutive nights. On the third night alcohol was administered (BAC = 0.154 g/100 mL). We observed no effect of alcohol on the size, duration, or number of erections. These results were confirmed in dogs. The latent period, magnitude, and duration of corpus cavernosal pressure changes produced by pelvic nerve stimulation were not affected by mean blood alcohol levels of 0.327 g/100 mL in three dogs. These results suggest that the inhibition of sexual response caused in conscious subjects by the ingestion of alcohol is not due to a suppression of the underlying spinal reflex but may be the result of its effect on perceptual or cognitive sexual mechanisms.

Prostaglandin E1 therapy for impotence, comparison with papaverine

The efficacy of prostaglandin E1 as a pharmacological treatment of erectile dysfunction (impotence) was compared with the standard treatment, papaverine, in a single blind, crossover trial. A total of 129 impotent men received intracavernous injections of either prostaglandin E1 (5 micrograms) or papaverine (18 mg.) 1 month apart. Observations by 1 observer recorded 10 to 20 minutes after injection demonstrated that prostaglandin E1 generated a better erection in 72 men (55.8%) compared to papaverine. Papaverine was more effective than prostaglandin E1 in 23 men (17.8%, chi-square 6.26, p less than 0.025). Subjective assessment by the patients who detected a difference showed that 71 (55%) preferred prostaglandin E1 and 35 (27%) preferred papaverine (chi-square 11.56, p less than 0.001). A total of 34 men achieved full erections with prostaglandin E1 compared to 17 who used papaverine.

Complications associated with penile implants used to treat impotence

The complications associated with a variety of penile prostheses used in the treatment of 302 men with erectile dysfunction are described. Infection of the prostheses resulted in their removal from 11 patients (3.6%), antibiotic therapy and replacement in five men. Mechanical failures required reoperation in 43 men (14.2%); however, recent advances in prosthesis design have reduced this type of malfunction. Adverse psychological reactions prompted removal of the prostheses from two men. Despite these complications, this surgery is remarkably effective.

Treatment of impotence by intrapenile injections. A comparison of papaverine versus papaverine and phentolamine: a double-blind, crossover trial

The efficacy of papaverine, and a combination of papaverine and phentolamine as a pharmacological treatment of impotence was compared in a double-blind, crossover trial. A total of 40 impotent men received intracavernous injections of papaverine (40 mg.) or a combination of papaverine (20 mg.) and phentolamine (0.5 mg.) at monthly intervals. Observations at 20 minutes after injection demonstrated that papaverine caused full erections in 27 per cent of the men and partial erections in 65 per cent. The combined injection resulted in full erections in 48 per cent of the men and 52 per cent had partial erections. The difference was significant (Z equals 2.29, p less than 0.05).

The role of dynamic corpora cavernosography in the management of impotence

Sixty eight impotent men underwent corpora cavernosography and corpora cavernosal pressure measurements during saline infusion. Nineteen of the men had internal pudendal arteriograms. Correlation between the cavernosograms and saline infusion induced pressure measurements was "good" in 56/66(84%), "approximate" in 5/66(8%) and there was no correlation in 5/66(8%). Two patients were excluded for technical reasons. The spread of results and the good correlation of the two tests speaks for the accuracy of the method. It was of value in diagnosis and will be of paramount importance if veno occlusive surgery becomes a reliable method of treatment.

Treatment of impotence by intrapenile injections of papaverine and phenoxybenzamine: a double blind, controlled trial

The efficacy of papaverine and phenoxybenzamine as a pharmacological treatment of impotence was compared in a double blind, crossover, placebo controlled trial. Thirty-four impotent men received intra-cavernosal injections of papaverine (60 mg), phenoxybenzamine (6 mg) or normal saline (10 ml) at monthly intervals. Observations by EJK up to 45 minutes after injection demonstrated that papaverine caused full erections in 35% of men and partial erections in 62%. Phenoxybenzamine injection resulted in full erections in 20% of men and 62% had partial erections. The differences were not significant. Despite 82-97% of patients attaining some degree of erection in the clinical setting only six of the patients decided to use this mode of treatment for more than three months. Sexual function during the month after injection was better with either drug when compared with placebo.

Epithelial bridging on burn patients following primary excision and grafting

Early tangential excision and primary grafting of full thickness and deep partial thickness burns has become a widely accepted practice, however, little attention has been paid to the epithelial bridging phenomenon, which occurs most frequently at the edge of these wounds. Over 5 years, 923 burn patients were treated and 407 were grafted, of whom 13 developed sufficiently severe epithelial bridging to require deroofing under general anaesthetic. Histological sections show that the bridges are derived from hair follicles. We advocate that patients with epithelial bridges should be observed in the outpatient department for many weeks and surgical intervention should only be used when they fail to resolve spontaneously.

Experience in the management of erectile dysfunction using the intracavernosal self-injection of vasoactive drugs

We report the results of a survey of 75 patients with erectile dysfunction, all of whom were treated by self-injection of the corpora cavernosa with vasoactive agents. At the time of the survey each patient had been self-injecting at home for at least 3 months. Of the patients 62 were followed for 3 to 21 months. Patients used this form of treatment with minimal assistance from our clinic staff. It was acceptable to them with few complications except for prolonged erections in 11 per cent of the men. Fifteen patients (24 per cent) with psychogenic impotence reported spontaneous improvement in erections during treatment and 4 discontinued treatment for this reason. Another 26 patients (42 per cent) continue to use self-injection as the definitive mode of treatment for erectile dysfunction.

The number of spermatozoa, the number of ovulations per ewe, and immunization against androstenedione affect fertility and prolificacy of sheep

Ewes that were untreated, fed lupins or fed lupins and immunized against androstenedione were artificially inseminated. The percentage of ewes pregnant at 36-45 days after insemination (fertility) was 8% higher in ewes that had more than one ovulation than in those that had only one ovulation. Maximum fertility was achieved with 50 x 10(6) spermatozoa and this did not vary with the number of ovulations that ewes had. Among the pregnant, twin-ovulating ewes, embryo survival increased as the number of spermatozoa inseminated increased from 25 x 10(6) to 400 x 10(6). Immunization of ewes against androstenedione increased ovulation rate but reduced fertility, and reduced embryo survival among twin-ovulation ewes.

Prolonged erections following intracorporeal injection of medications to overcome impotence

We describe the management of 17 men who developed prolonged erections following the intracorporeal injection of vasoactive drugs (e.g. papaverine) for the treatment of erectile dysfunction. Twelve men who had psychogenic impotence developed prolonged erections following injection compared with 5 who had an organic aetiology. The aspiration of 20 to 50 ml of blood from the penis together with the intracorporeal injection of 1 to 2 mg metaraminol is an effective treatment of this complication.

Autonomic control and vascular changes during penile erection in monkeys

The mean pressure in the unstimulated corpus cavernosum of monkeys was 12.1 mm Hg. Pelvic nerve stimulation at 8 to 10 Hz produced penile extension and the mean pressure increased to 64.3 mm Hg (47-84% of carotid artery pressure) after a latency of 10 s. On stopping stimulation, recovery to resting levels occurred within 2 min. The response was not blocked by atropine or propranolol. Blood flow through two 19 gauge needles inserted into the corpus cavernosum increased in parallel with the pressure changes, indicating that arterial inflow increased. Stimulation of either hypogastric nerves or the sympathetic chain produced penile retraction but increased corpus cavernosal pressure. The response to pelvic nerve stimulation was partially blocked. It was concluded that both of these nerves contract penile erectile tissue within the corpus cavernosum and constrict arterial inflow.

Vascular changes during penile erection in the dog

1. The vascular effects of pelvic nerve stimulation on the penis were studied in dogs anaesthetized with sodium pentobarbitone and halothane. Changes in pressure and blood flow were measured through scalp vein needles inserted into the erectile bodies. 2. The penis contains two types of erectile body, which responded independently during erection induced by pelvic nerve stimulation. Pressure in the corpus spongiosum increased immediately upon stimulation, but only reached one-third of the more delayed pressure response of the corpora cavernosa. 3. At rest, arterial inflow resistance into the corpora cavernosa was high, whereas venous outflow resistance was low. Pelvic nerve stimulation (10-50 V, 10-16 Hz, 1 ms) caused an immediate increase in arterial flow, an increase in corpus cavernosal pressure (CCP), and a decrease in venous outflow. Saline infusion experiments showed there was active venous occlusion. Upon cessation of stimulation, these parameters returned to pre-stimulation levels. 4. The time taken to reach 50% of maximum change in arterial inflow was significantly less than for CCP, which was significantly less than for venous outflow. Occlusion of the aorta 1 min after cessation of stimulation decreased the pressure in the arterial tree supplying the corpora cavernosa, but CCP remained elevated, indicating that both inflow and outflow resistances were high. Thus, inflow resistance had returned to its pre-stimulation state before outflow resistance. 5. Direct measurements of blood flow through the corpus cavernosum were made with a hydrogen probe. There was a transient increase in blood inflow as CCP increased during pelvic nerve stimulation. There was some blood flow while CCP was elevated, indicating that the venous occlusion was not complete. 6. Sympathetic chain stimulation caused an increase in arterial resistance, and a decrease in CCP and venous resistance. 7. Infusions of acetylcholine (330 micrograms min-1) and vasoactive intestinal polypeptide (1-3.3 micrograms min-1) decreased arterial resistance and increased CCP and venous resistance. 8. This study suggests that during pelvic nerve-induced erection, arterial flow into the corpus cavernosum increases, followed by an increase in CCP and an actively controlled decrease in venous outflow.(ABSTRACT TRUNCATED AT 400 WORDS)

Experience with the Nesbit procedure in the treatment of penile curvature

Thirteen men who had undergone Nesbit's operation for penile curvature were assessed to determine the efficacy of the procedure. Ten patients had Peyronie's disease and three had a congenital curvature. Follow-up ranged from 8 months to 28 months. The degree of penile curvature was improved in twelve patients at the time of follow-up. The three men with a congenital curvature were all satisfied, whereas only seven of the 10 with Peyronie's disease were satisfied with the results of surgery. Two men believed that the operation had reduced their erectile function and a third man felt that the operation had not improved his penile deformity. Patients with a penile curvature associated with deteriorating erectile function should be counselled that a Nesbit's procedure will not improve their potency and that the insertion of a malleable penile prosthesis may be necessary.

Autonomic control of penile erection in the dog

1. In anaesthetized dogs, resting mean penile artery pressure (p.a.p.) and corpus cavernosum pressure (c.c.p.) were 70-100% and 10-15% of mean systemic blood pressure, respectively. 2. Stimulation of the pelvic nerve at 10 Hz produced an immediate drop in p.a.p. and c.c.p., followed 10-30 s later by a rise in c.c.p. to the level of p.a.p. This level was 60-90% of systemic pressure, and was maintained throughout stimulation. 3. The threshold for a rise in c.c.p. was 3-5 Hz. Atropine (1 mg/kg), phentolamine (200 micrograms kg-1) and propranolol (200 micrograms kg-1) had no effect on the response to pelvic nerve stimulation. 4. C.c.p., p.a.p. and their changes in response to pelvic nerve stimulation were not significantly altered by either stimulation or section of the hypogastric nerves. 5. Cutting the sympathetic chain on both sides at L5, or administration of phentolamine, had no effect on resting c.c.p. or p.a.p. However, subsequent responses to pelvic nerve stimulation were enhanced. 6. When the pelvic nerve was stimulated during excitation of the sympathetic chain, there was still an initial drop in p.a.p. and c.c.p. but the subsequent increase in c.c.p. was delayed or abolished. These effects were mimicked by close arterial injection of phenylephrine and blocked by alpha-adrenergic antagonists. 7. This study suggests that erections in response to pelvic nerve stimulation result from an initial increase in volume of the corpus spongiosum, followed 20 s later by a stiffening of the corpus cavernosum as its pressure increases. Only the latter process is inhibited by activity of the sympathetic fibres.

Pharmacology of the erectile tissue of the canine penis

To assess the role of different neuroeffector systems in penile erection, pharmacological agents were tested in vitro using strips of corpus cavernosum tissue from the dog. Alpha-adrenoceptor agonists, K+ or histamine caused concentration-dependent contraction. Tyramine caused a poorly sustained contraction, as did nicotine in some cases. In precontracted preparations, relaxation was caused by beta2-adrenoceptor or muscarinic cholinoceptor agonists, or by vasoactive intestinal peptide. The results suggest that a noradrenergic alpha-adrenoceptor system maintains penile flaccidity in the dog. Penile erection may result from the activation of inhibitory beta2-adrenergic, muscarinic and/or peptidergic systems.

Human anti-luteinizing hormone-releasing hormone antibodies in patients treated with synthetic luteinizing hormone-releasing hormone

One hundred sixty-three patients who were given synthetic LH-RH therapeutically underwent monitoring of serum IgG anti-LH-RH antibodies. Five of the patients showed specific binding to antibodies. Development of anti-LH-RH antibodies was not limited to those patients with a congenital deficiency of LH-RH. Urticarial responses occurred in four patients, only one of whom had IgG antibodies. Patients who had IgG antibodies or an urticarial response underwent monitoring of their serum IgE anti-LH-RH antibodies, but none had a positive binding response. The refractory state which has been reported in patients in whom similar antibodies to LH-RH develop was not invariably observed among these patients.

Ovulation induction with pulsatile gonadotrophin releasing hormone (GnRH)

Anovulatory infertility has been successfully treated in 7 out of 13 women by means of pulsatile gonadotrophin releasing hormone (GnRH) therapy. Women with primary or secondary amenorrhoea received a bolus of GnRH (2.1-20 micrograms) subcutaneously once every 60, 90 or 120 min around the clock from a programmable, battery operated, syringe driver worn under the clothing. Duration of treatment varied from 1 week to 8 months (mean 2.5 months); 7 women ovulated and 2 conceived in the first month of treatment. We conclude that anovulatory women with normal prolactin levels, who are refractory to clomiphene with or without HCG, and who are unlikely to respond to anything but human pituitary FSH and HCG may now be treated with GnRH.

Treatment of cryptorchidism with pulsatile luteinizing hormone-releasing hormone (LH-RH)

This preliminary report describes a new method of treating bilateral cryptorchidism that may modify the need for surgical intervention. Four of five boys (3 1/2, 3 1/2, 7, 11 and 12 1/2 years of age) given hourly subcutaneous pulses of luteinizing hormone-releasing hormone (LH-RH, 10 to 100 micrograms/day, given in a 3-min pulse every hour) showed evidence of testicular descent after 3 to 19 weeks. The battery-operated, programmable syringe driver was well tolerated by the boys, and the daily insertion of the scalp-vein needles was managed at home by their parents.

A pharmacological and ultrastructural study of the rabbit gubernaculum testis

This study provides an ultrastructural and pharmacological description of the contractile apparatus of the rabbit gubernaculum testis. This organ contained an abundance of innervated striated muscle as well as sparse populations of smooth muscle cells that were associated with blood vessels. Investigation of the pharmacological properties of isolated preparations of rabbit gubernaculum confirmed that striated muscle was the major contractile component in this tissue. Results also indicate that a significant proportion of these muscle fibres contained multiple neuromuscular junction sites. This study supports the suggestion that the gubernaculum testis may be sufficiently contractile to induce testicular descent.

Impotence--the team approach to investigation and surgical treatment

A multidisciplinary study group was established to assess impotent patients. One hundred and forty-eight patients were fully assessed and 25 potent volunteers underwent measurement of nocturnal penile tumescence (NPT). This report describes the selection process and results of surgical implantation of the American Medical Systems (AMS) inflatable and the Jonas silver-silicone prostheses.

Hypophysial responses to continuous and intermittent delivery of hypopthalamic gonadotropin-releasing hormone

In rhesus monkeys with hypothalamic lesions that abolish gonadotropic hormone release by the pituitary gland, the constant infusion of exogenous gonadotropin-releasing hormone (GnRH) fails to restore sustained gonadotropin secretion. In marked contrast, intermittent administration of the synthetic decapeptide once per hour, the physiological frequency of gonadotropin release in the monkeys, reestablishes pituitary gonadotropin secretion. This phenomenon is attributable to the pattern of GnRH delivery rather than to the amounts of this hormone to which the cells of the pituitary are exposed. Moreover, the initiation of continuous GnRH administration in animals with lesions and in which gonadotropin secretion is reestablished by intermittent GnRH replacement can result in a "desensitization" or "down regulation" of the processes responsible for gonadotropin release.

On the sites of the negative and positive feedback actions of estradiol in the control of gonadotropin secretion in the rhesus monkey

Ovariectomized rhesus monkeys bearing hypothalamic lesions which had abolished endogenous LHRH production, as evidenced by a profound reduction in gonadotropin secretion, but in which LH and FSH secretion was reestablished by a chronic intermittent iv infusion of synthetic LHRH (1 microgram/min for 6 min every hour) were used to investigate the sites of the negative and positive feedback actions of estradiol in the control of gonadotropin secretion. The administration of estradiol to such animals, while continuing the LHRH replacement regimen, resulted in a decline in circulating LH and FSH levels, followed by an unambiguous discharge of these hormones. The time course of this biphasic pattern of gonadotropin secretion was remarkably similar to that observed in response to estradiol administration in otherwise intact ovariectomized animals. These results suggest that, in the rhesus monkey, estradiol can exert both its negative and positive feedback actions on gonadotropin secretion at the level of the pituitary gland.

Studies on the relationship between FSH and germ cells: evidence for selective suppression of FSH by testicular extracts

The evidence supporting the relationship between the seminiferous epithelium and circulating FSH levels has been reviewed and provides support for the concept that the testis produces a factor capable of specifically controlling FSH concentrations. Detailed quantitative histological studies of the seminiferous epithelium have demonstrated a highly significant inverse relationship between the number of spermatogonia per tubule cross-section and serum FSH levels in men with testicular disorders.

Selective suppression of FSH by testicular extracts

Studies were undertaken to determine the effects of intravenous infusions of bovine testicular extracts on plasma levels of FSH and LH in castrate male sheep. Decapsulated bovine testes were homogenized with phosphate buffer, the homogenates centrifuged at 30,000 X g for 30 min, and the supernatants extracted with diethyl ether. The aqueous extracts were filtered using Diaflo XM-100 membranes and the ultra-filtrates lyophilized. The extracts were infused over 24 hours, and plasma FSH and LH were measured prior to, during, and after the infusion. Control studies using infusions of saline and liver extracts demonstrated no decrease in FSH levels in 6 out of 7 controls, while LH levels tended to rise. Following infusions with the testicular extracts, the levels of FSH were selectively decreased to between 42% and 85% of baseline levels, and they subsequently remained suppressed for at least 24 hours. These results suggest that the testis is the site of production of a water-soluble, non-steroidal substance which exerts an inhibitory effect on the production and/or release of FSH.

Regulation of gonadotrophin secretion in rams from birth to sexual maturity. I. Plasma LH, FSH and testosterone levels

Plasma LH, FSH and testosterone concentrations were measured by radioimmunoassays in male crossbred Merino/Corriedale sheep from birth to 45 weeks of age. FSH levels were 11 and 22 ng/ml at birth, increased to peak levels (mean value of 47 ng/ml) at 5 weeks and fluctuated between 25 and 35 ng/ml for the next 40 weeks. Similarly, LH (less than 0-5 ng/ml) and testosterone (less than 38 ng/100 ml) levels were low at birth and were significantly elevated by 5 weeks of age. LH values varied betwen 0-9 and 3-0 ng/ml for the next 30 weeks and then a secondary rise occurred reaching levels of 2-4 ng/ml by the 41st week after birth. Concentrations of LH subsequently fell to levels observed in adult rams. Testosterone levels rose gradually between the 5th and the 25th week, and then increased rapidly to values of 270-517 ng/100 ml by the 41st week after birth, a time coincident with the peak LH levels. Histological examination of testicular biopsies demonstrated that Sertoli cell maturation occurred 17-21 weeks after birth and was followed by activation of spermatogenesis leading to the presence of spermatozoa in the seminiferous epithelium by 39-42 weeks of age.

Regulation of gonadotrophin secretion in rams from birth to sexual maturity. II. Response of the pituitary-testicular axis to LH-RH infusion

The response of the pituitary-testicular axis to LH-RH infusion was investigated in rams from birth to sexual maturity. During early postnatal life ram lambs were responsive to LH-RH stimulation and heightened pituitary sensitivity was observed in rams aged 2-3 months. It is suggested that a change in sensitivity of the pituitary-testicular axis occurs at this time and perhaps represents the time of initiation of the pubertal process.

The HCG stimulation test in men with testicular disorders

The rise in plasma testosterone levels following stimulation with human chorionic gonadotrophin (3000 i.u./day for 4 days) has been used as a test of interstitial cell function in normal men and men with testicular disorders. The large majority of patients with testicular disorders resulting in infertility, showed a subnormal testosterone response to stimulation. The most marked impairment was noted in those patients with the biopsy appearance of germinal cell arrest and Sertoli cell only syndrome.