Hyperprolactinaemia and impotence

Hyperprolactinemia and male sexual function: focus on erectile dysfunction and sexual desire

The present paper aims to analyze and discuss the available evidence supporting the relationship between male sexual function and elevated prolactin (PRL) levels (HPRL). Two different sources of data were analyzed. Clinical data were derived from a series of patients seeking medical care for sexual dysfunction at our Unit. Out of 418 studies, 25 papers were used with a meta-analytic approach to evaluate the overall prevalence of HPRL in patients with erectile dysfunction (ED) and to study the influence of HPRL and its treatment on male sexual function. Among 4215 patients (mean age 51.6 ± 13.1 years) consulting for sexual dysfunction at our Unit, 176 (4.2%) showed PRL levels above the normal range. Meta-analytic data showed that HPRL is a rare condition among patients with ED (2 [1;3]%). Either clinical and meta-analytic data confirm a stepwise negative influence of PRL on male sexual desire (S = 0.00004 [0.00003; 0.00006]; I = -0.58915 [-0.78438; -0.39392]; both p < 0.0001 from meta-regression analysis). Normalization of PRL levels is able to improve libido. The role of HPRL in ED remains inconclusive. Data from a meta-analytic approach showed that either HPRL or reduced T levels were independently associated with ED rates. The normalization of PRL levels only partially restored ED. HPRL did not significantly contribute to ED severity, in our clinical setting. In conclusion, treating HPRL can restore normal sexual desire, whereas its effect on erection is limited.

Sexual Dysfunction in Patients With Chronic Gastrointestinal and Liver Diseases: A neglected Issue

INTRODUCTION

Normal sexual activity is an important determinant of quality of life. Unfortunately, several chronic health disorders are associated with an impaired sexual function.

OBJECTIVE

To provide coverage of the current literature on prevalence and pathophysiology of sexual dysfunction in patients with gastrointestinal and liver disorders METHODS: A Comprehensive review of the literature on the prevalence of sexual dysfunction in chronic gastrointestinal and liver disorders, assessing the underlying mechanism (s) was performed.

RESULTS

Many gastrointestinal disorders, either functional or organic, are associated with some degree of sexual dysfunction. The main pathogenic mechanisms are: (i) the disease itself causing fatigue, anxiety or depression with a potential alteration of self-esteem; (ii) worry of transmitting a potential infectious agent through sexual activity; (iii) alteration of the endocrine mechanisms which are necessary for normal sexual functioning; (iv) chronic pro- inflammatory conditions which may cause endothelial dysfunction and abnormal vascular responses; (v) iatrogenic.

CONCLUSION

Based on this review, a thorough evaluation of sexual function through validated questionnaires and/or psychological interviews with patients with chronic gastrointestinal disorders should be part of the clinical assessment in order to timely diagnose and possibly treat sexual dysfunction in this clinical setting. L Romano, L Granata, F Fusco, et al. Sexual Dysfunction in Patients With Chronic Gastrointestinal and Liver Diseases: A neglected Issue. Sex Med Rev 2022;10:620-631.

Effect of Vitamin E Therapy on Sexual Functions of Uremic Patients in Hemodialysis

Twenty-four uremic patients on hemodialysis who had never been treated with vitamin E or related drugs and 12 control patients with normal renal function were studied. Hemodialysis patients were randomly divided into two groups; 12 were treated with oral vitamin E (300 mg/day) for eight weeks and 12 uremic patients and 12 controls were given placebo. Serum vitamin E, prolactin, FSH, LH, and free testosterone levels were measured in all patients before and after treatment. After the vitamin E treatment serum prolactin levels were significantly decreased (50.8 vs 15.4 ng/ml, p<0.01). Vitamin E levels were significantly increased (1.11 vs 1.22 mg/dl, p<0.05). Serum FSH, LH and free testosterone were not affected. In the other two groups there were no significant changes. These results show that vitamin E treatment lowers prolactin levels in uremic hemodialysis patients. This might be due to inhibition of central prolactin secretion. Vitamin E inhibits pituitary gland hypertrophy in vitamin E-deficient rats.

Cerebrospinal Fluid Rhinorrhoea in Pituitary Tumours

Three cases of CSF rhinorrhoea due to pituitary tumours are reported and the literature reviewed. The treatment of choice appears to be trans-sphenoidal exploration of the pituitary fossa with insertion of a free muscle graft followed by radiotherapy. The probability of the tumour being a prolactin-secreting adenoma is discussed.

Prolactin and Impotence in Diabetes Mellitus

A study was undertaken to determine whether impotence in some diabetic patients might be due to a coincidental prolactinoma and therefore be potentially treatable. Of 83 consecutive men attending a diabetic clinic, three were found to have persistent mild to moderate hyperprolactinaemia. None of the three was impotent or taking any drug known to be associated with elevated serum prolactin, and anterior pituitary responses and pituitary fossa tomograms did not reveal any abnormality. The mean serum prolactin concentration of the 37 insulin-treated men was not significantly different from that of the 46 men on diet with or without anti-diabetic tablets, nor was there any significant difference between the mean serum prolactin concentrations of the 19 impotent men and of the 64 non-impotent men.

The epidemiology of pituitary adenomas in Iceland, 1955-2012: a nationwide population-based study

OBJECTIVE

Pituitary adenomas (PA) are among the most common human neoplasms. To describe the epidemiology and assess the disease burden of clinically significant PAs, population-based studies are needed. Iceland has a small well-defined population. The aim of this study is to describe the epidemiology of PAs in Iceland over an expanded period of time.

DESIGN

This is a retrospective observational study, including all PAs diagnosed in Iceland from 1955 to 2012.

METHODS

Extensive clinical information was gathered in a database. Prevalence rates for all PA subtypes were calculated along with standardized incidence rates (SIR). Sex ratios and relationships with adenoma size, age, and symptoms were assessed.

RESULTS

We identified 471 individuals: 190 men and 281 women. Total prevalence in 2012 was 115.57/100, 000, prolactinomas were most prevalent (54.37/100, 000) followed by non-functioning adenomas (NFPAs) (42.32/100 ,000). Throughout the period, NFPAs were most common (43.0%) followed by prolactinomas (39.9%) and 11.3% had acromegaly and 5.7% Cushing's disease. Women are diagnosed younger with smaller adenomas. Total SIR has increased significantly and is now 5.8/100 000 per year.

CONCLUSION

In this nationwide study spanning six decades, we have confirmed PAs rising prevalence and incidence rates noted in recent studies. We demonstrated higher overall prevalence and incidence rates than ever previously recorded with an increasing predominance of NFPAs, which is not explained by incidental findings alone. There is a relationship with the introduction of imaging modalities, but the vast majority of patients are symptomatic at diagnosis. This underlines the importance of increased awareness, education, and appropriate allocation of resources for this growing group of patients.

Biochemical endocrinology of the hypogonadal male

Hypogonadism in the male results from inadequate testicular function, especially defects in androgen synthesis and secretion, or action. Androgen action is important throughout normal male development: in the fetus, puberty, adult life and old age. Regulation is by variable activity of the hypothalamo-pituitary axis at different phases of the life span. Clinical aspects include: genetic aspects presenting at birth and pubertal failure/arrest. Aspects in adult life embrace sexuality, somatic symptoms and osteoporosis. Acquired causes of hypogonadism may arise from various forms of testicular damage (primary hypogonadism), pituitary and hypothalamic disorders, as well as aetiologies acting at several sites. Measurement of testosterone (T) is crucial to the diagnosis of hypogonadism and the technologies continue to develop, with recent major advances. A growing problem relates to the diagnosis and treatment of hypogonadism in the ageing male. T therapy is available in several forms, with major improvements in more newly available modalities.

Serum and seminal plasma prolactin levels in male attenders of an infertility clinic in Ibadan

Serum and seminal plasma prolactin and testosterone were studied in 51 healthy-looking men who presented at the infertility clinic. They included 20 men with normospermia, 20 with oligospermia and 11 with azoospermia. The mean serum prolactin and gonadotrophin levels of the oligospermics and azoospermics were similar but significantly higher than those of the normospermics. The mean seminal plasma prolactin levels in the three groups were similar. The mean serum testosterone of the azoospermics was significantly higher than those of the oligospermics and normospermics who had similar levels. The seminal plasma testosterone of the oligospermics was similar to that of the azoospermics but significantly higher than that of the normospermics. A significant correlation occurred between serum prolactin and sperm motility. No correlation occurred between the serum and seminal plasma prolactin levels, and seminal plasma testosterone or between serum and seminal plasma testosterone. Seminal prolactin has no correlation with any biophysical parameters. It was concluded that poor spermatogenesis is associated with high serum prolactin in patients with infertility. Serum but not seminal plasma prolactin assay is useful in assessing male infertility.

Sexual function and pituitary axis in insulin treated diabetic men

The prevalence of sexual dysfunction and the pituitary-gonadal function were studied in 72 consecutive diabetic male patients. Sexual dysfunction was found in 43% and in these patients peripheral neuropathy was significantly more frequent than in patients with normal sexual function. Sexual dysfunction was more frequent in patients at the age of 50--55 years than in young diabetics (age 25--30 years). No significant correlation between sexual dysfunction and the duration of the disease and no difference in the serum concentrations of luteinizing hormone, follicle stimulating hormone, prolactin, testosterone and oestradiol-17beta between patients with normal and reduced sexual function was found. It is concluded, that sexual dysfunction is not accompanied by altered serum concentrations of testosterone, oestradiol 17beta, gonadotrophins or prolactin. Sexual dysfunction correlates with peripheral neuropathy, but the high prevalence of dysfunction in males with short duration of diabetes without neuropathy makes other causes likely.

Prolactinomas in men: clinical characteristics and the effect of bromocriptine treatment

Thirty-seven men with prolactin (PRL) producing pituitary adenomas were studied to elucidate if patient's delay might cause the predominance of large tumours in men as compared to women in whom microadenomas predominate. We found two clinical subgroups; one presented with short duration of symptoms, dominated by local signs from the growth of notably large tumours, the other exhibited a long history of disease with hypogonadism as the dominating symptom. There was a correlation between tumour size and PRL levels. The age at the time of diagnosis showed no correlation to duration of symptoms, size of adenoma or PRL levels. Four patients with small adenomas, moderate hyperprolactinemia and short duration of symptoms showed signs of hypergonadotropic hypogonadism. Surgery or irradiation, performed in 14 patients, did not normalize PRL levels. Bromocriptine was equally beneficial in the two clinical subgroups, improving clinical symptoms and normalizing PRL levels in all but three patients. The study shows that the predominance of large tumours in men does not depend on patient's or doctor's delay, but on a high frequency of presumably rapidly growing PRL producing tumours. In the majority of patients, these tumours do not give signs of hypogonadism before the tumour is revealed by local signs of tumour growth.

Gynecomastia with sulpiride

OBJECTIVE

Neuroleptic agents have been associated with gynecomastia, but evidence for a causal link is insufficient. We describe a case of unilateral gynecomastia without galactorrhea in a 38-year-old man during sulpiride treatment for generalized anxiety disorder. The patient had been treated with sulpiride (100 mg/day) for about 5 months by a primary care physician. In this patient, no specific endocrine alterations were found, except for a marked increase in prolactin (PRL) level and slight decrease in testosterone (T)/estradiol (E2) ratio. Drug withdrawal led to a reduction of the lump. Sulpiride is a substituted benzamide with selective dopaminergic blocking activity. From the marked increase in PRL level and the slight decrease in T/E2 ratio observed during sulpiride therapy, it is proposed that sulpiride may induce gynecomastia by inhibiting hypothalamic-pituitary function directly, and/or indirectly through hyperPRLemia.

Seizures, hormones and sexuality

Sexual disorders (both hyposexuality and sexual dysfunction) are common in people with epilepsy, occurring in up to two-thirds of patients. However, characteristically, patients do not spontaneously report these problems. Nocturnal penile tumescence testing suggests that the erectile dysfunction has a neurophysiological component. The aetiology remains uncertain but is likely to be multifactorial, involving neurological, endocrine, iatrogenic, cognitive, psychiatric and psychosocial factors. Epilepsy-related factors include the age of onset/duration of epilepsy along with the seizure type and focus. In addition, seizure frequency might be relevant as successful epilepsy surgery can result in an improvement in sexual functioning despite remaining on anticonvulsant medication. Endocrine changes (raised sex hormone binding globulin and reduced free testosterone) have been reported in men with epilepsy, especially when treated with hepatic-enzyme inducing antiepileptic drugs. Studies have not been performed evaluating anticonvulsants that do not induce hepatic enzymes such as lamotrigine. The association between these endocrine changes and hyposexuality is not known. The relationship between seizures, hormones and anticonvulsant medication in women is explored, focusing on issues such as catamenial epilepsy, the menopause, hormone replacement therapy and the polycystic ovarian syndrome. Suggestions for future research and treatment issues are discussed.

The "low-dose" concept and the paradoxical effects of prolactin on grooming and sexual behavior

The effects of prolactin on animal behavior include the stimulation of novelty-induced grooming in rats. This effect has been demonstrated in hyperprolactinaemic animals bearing pituitary homografts under the kidney capsule or after intracerebroventricular (i.c.v.) administration of prolactin. Since plasma prolactin levels in hyperprolactinaemic rats are similar to those of animals injected with low doses of rat prolactin, we studied the effects of this hormone injected subcutaneously (s.c.) in a dose range of 5-50 microg/kg. Novelty-induced grooming was enhanced only in rats injected with 5 or 10 microg/kg rat prolactin, whereas no effect was observed after the s.c. injection of the higher dose. The sexual behavior of male rats is also affected by prolactin. Male rats with normal mating activity showed enhanced sexual behavior when injected s.c. with rat prolactin (5, 10 or 50 microg/kg). In animals with poor sexual performance or in impotent rats, prolactin (5 or 10 microg/kg, but not 50 microg/kg) restored the full pattern of sexual behavior. An increased lordosis quotient was also observed in ovariectomized rats treated with prolactin 5 or 10 microg/kg. These results suggest that, besides the duration of hyperprolactinaemia, the effective level of plasma prolactin is important for the expression of the behavioral effects of this hormone.

Libido and hormones

Libido is the drive to have a sexual activity. Gonadal hormones play a major role in activating and maintaining libido in both men and women. Other hormones, though, interact with them in influencing sexuality, such as prolactin and also brain neurotransmitters. The role of hormones declines with age and sexuality becomes more mind-induced. Nevertheless, some aspects of sexuality remain linked to hormones. For example, a reduction of central arousability is typical of hypogonadal state. However, it is not clear at what level of androgen deficiency the loss of libido begins and if adequate external stimuli can overcome a partial deficiency.

Bromocriptine for infertile males with mild hyperprolactinemia: hormonal and spermatogenic effects

To clarify the influence of hyperprolactinemia on spermatogenesis and steroidogenesis in infertile male patients, the serum prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, and estradiol concentrations were and the effect of bromocriptine treatment on spermatogenesis was examined. A total of 1234 patients were evaluated and 147 men had hyperprolactinemia. Of these, only 30 had PRL concentrations more than twice the upper limit of normal and most of them had a little excess over the upper limit. For 10 of these 30, serum hormone concentrations were measured and semen was analyzed before and after bromocriptine administration. No relationship between the PRL and other hormone concentrations was found. No changes were noted in the LH, FSH, testosterone, or estradiol concentrations, or in the sperm density and motility after treatment. The mean PRL decreased from 26.5 +/- 4.5 to 1.4 +/- 1.8 ng/mL. In infertile men who are mildly hyperprolactinemic, bromocriptine administration does not improve semen analysis, although it does normalize the PRL.

Hyperprolactinaemia in males: a heterogeneous disorder

BACKGROUND

The literature suggests that men with prolactinomas typically present with pressure effects of large pituitary tumours and/or the clinical features of hypogonadism. A definitive study of the clinical features of hyperprolactinaemia in males is, however, lacking

AIMS

To identity the clinical, biochemical and radiological features of hyperprolactinaemia in males.

METHODS

Retrospective review of the case notes of 53 adult males with prolactinoma or idiopathic hyperprolactinaemia diagnosed 1980-1995.

RESULTS

The mean age of the patients was 41 years (range 19-75). The presenting symptom was endocrine in nature in 57% of patients (loss of libido/potency 47%, gynaecomastia 6%, galactorrhoea 2%, sparse beard growth 2%), pressure effects of pituitary tumour in 28% (headache 13%, visual loss 13%, diplopia 2%), while 15% of patients presented incidentally. On physical examination, galactorrhoea was present in 8% of patients, gynaecomastia in 23% and abnormally sparse body hair in 21%. Testicular volume was normal (> or = 15 mL) in all but two patients, both of whom had evidence of delayed pubertal development. Visual loss was present in 17% of patients. Serum prolactin ranged from 800 to 1.7 million mU/L (median 20,000 mU/L, reference range < 500), and serum testosterone from 0.7 to 19.3 nmol/L (mean 7.8 nmol/L, reference range ten-35). Pituitary imaging by computed tomography (45%) or magnetic resonance imaging (55%) demonstrated macroadenomas in 70% of patients, microadenomas in 15%, and no detectable tumour in 15% of subjects. On bromocriptine treatment (47 subjects), 89% of patients reported improved sexual function. Follow up imaging in 36 patients with abnormal scans at presentation revealed tumour shrinkage in 89% of cases.

CONCLUSIONS

Hyperprolactinaemia in males is a heterogeneous disorder. The majority of patients have prolactin-secreting macroadenomas, but there is wide variation in presenting symptoms, physical signs and results of biochemical and imaging investigations. Bromocriptine treatment is associated with symptomatic improvement and a reduction in tumour size in most cases.

Hyperprolactinemia in men with asthenozoospermia, oligozoospermia, or azoospermia

The role of serum prolactin (PRL) in male infertility is still unclear. To assess the clinical significance of PRL determination during infertility studies, serum hormones and semen samples from 167 men attending the Andrology Clinic were analyzed, and PRL seric values were correlated with volume, sperm count, motility, viability, and morphology. The range of PRL levels (ng/mL) was 7.3 +/- 2.1 in the control group (n = 46), 13.9 +/- 6.6 in asthenozoospermic (n = 51), 12.6 +/- 7.8 in oligozoospermic (n = 42), and 10.9 +/- 4.8 in azoospermic patients (n = 28). Significantly higher (p < .0001) levels of PRL were found in the men with asthenozoospermia, oligozoospermia, and azoospermia. In the 121 infertile patients with abnormal semen analysis, serum PRL levels were below 14.0 ng/mL (normal mean + 3 SD) in 81 (66.9%) and above this level in 40 (33.1%) cases. Serum FSH and LH concentrations in azoospermic men were significantly higher (p < .0001) when compared with those of the control group, which indicates some disturbance of the spermatogenic process, and estradiol was significantly higher (p < .02) in oligozoospermic patients. No significant differences were found in serum testosterone. Twenty-one patients with idiopathic oligoasthenozoospermia and hyperprolactinemia were treated with 2.5 mg of bromocriptine daily for 6 months, resulting in a nonmeasurable effect on their sperm analysis. In conclusion, two-thirds of patients with oligozoospermia, asthenozoospermia, and azoospermia have normal PRL levels. Infertility in men due to moderate hyperprolactinemia could be associated with these sperm disturbances, but bromocriptine was of no therapeutic utility.

Endocrine screening for sexual dysfunction using free testosterone determinations

PURPOSE

Controversy exists concerning the need for routine endocrine screening in impotent men. Debate also continues as to what hormonal studies are necessary, the role of the free fraction of testosterone and whether a history of decreased libido or testicular atrophy can predict these endocrinopathies.

MATERIALS AND METHODS

We reviewed 508 consecutive men who presented with sexual dysfunction within a 22-month period. Testosterone data were available for 268 patients (53%) and prolactin data were available for 170 (33%).

RESULTS

Hypogonadism, defined as 2 abnormal total testosterone levels, was found in 42 of our 268 patients (15.6%). A history of decreased libido by patient questionnaire and/or testicular atrophy on physical examination could not predict these cases. A normal free fraction of testosterone saved further unnecessary endocrine evaluation in 50% of patients with hypogonadism. Hypoprolactinemia was noted in 3 of 170 patients (1.8%).

CONCLUSIONS

Routine endocrine screening remains a necessary part of the evaluation for sexual dysfunction. A history of decreased libido and/or testicular atrophy on physical examination cannot predict hypogonadism. Measurement of free fraction of testosterone will further lessen unnecessary endocrine evaluations by 50% and should become standard practice in screening for hypogonadism. Prolactin levels are necessary only in patients with hypogonadism and/or a history of decreased libido.

Diabetic sexual dysfunction

Although the overall incidence of erectile dysfunction in the general population between the ages of 40 and 70 years is 52%, men with diabetes mellitus have impotence at an earlier age and with a significantly higher prevalence, ranging as high as 75%. Numerous advances have been made in understanding the physiologic and biochemical mechanisms controlling penile erection. Improved clinical techniques for the diagnosis and treatment of impotence, including dynamic vascular testing, intracavernosal pharmacotherapy, and microsurgical revascularization, have allowed us to enter a new and exciting era in the quest for a more complete understanding of erectile dysfunction.

Routine prolactin measurement is not necessary in the initial evaluation of male impotence

The authors determined the prevalence of hyperprolactinemia in impotent men in a community setting and assessed the cost of case detection with routine estimation of serum prolactin. They recruited 299 consecutive patients with impotence and determined the hormonal levels (prolactin, luteinizing hormone, follicle-stimulating hormone, and testosterone). Pituitary gland imaging was done when the prolactin level was elevated. Simultaneous prolactin and testosterone levels were available for 212 patients. Three patients (1.4%) had elevated prolactin levels but none had pituitary tumor. Two of these had low testosterone levels. Overall, 51 patients (24.1%) had low testosterone levels. Cost of selective prolactin estimation in patients with low testosterone levels resulted in a net saving of $2,574 per case detected. The authors conclude that the prevalence of hyperprolactinemia in impotence is low. Routine measurement of prolactin levels in impotence is not indicated. Selective determination in patients with low testosterone reduces the cost of diagnostic evaluation.

Impotence: diagnosis and management of male erectile dysfunction

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Sexual function in women with hypothalamo-pituitary disorders

The extent to which hypothalamo-pituitary disorders in women affect sexual desire and sexual functions was investigated. Sexual functions and sexual appreciation were assessed in a comprehensive interview of 48 women with well-defined hypothalamo-pituitary disorders. Data about sex life were correlated to blood hormone levels and diagnosis. In most of the women (64.8%), the first clinical symptom indicating a hypothalamo-pituitary dysfunction began in the age group 16 to 35. In 43 patients (89.6%), the initial symptom was menstrual irregularities. Altogether 45 (93.8%) of the women declared that they had or had had significant sexual problems. Two of the three women who did not report sexual problems had never had intercourse. Thirty-eight (79.2%) of the women had developed a lack of or a considerable decrease in sexual desire. Problems with lubrication or orgasm were reported by 31 (64.6%) and 33 (68.7%) of the women, respectively. Normal menstrual pattern, young age, and intrasellar tumor growth correlated better with normal sexual desire and sexual functions than did normal prolactin levels and normal testosterone levels. However, at the time of interview, only 7 women had hyperprolactinemia. Serum testosterone values correlated significantly only with masturbation.

Successful gonadotrophin treatment of hypogonadism in postoperative patients with macroprolactinoma and persistent hyperprolactinaemia

We report on two males with prolactinoma in whom hyperprolactinaemia and hypogonadism persisted for several years postoperatively despite the administration of a dopamine agonist or bromocriptine. In these patients, a GnRH test revealed no response in the levels of serum LH or FSH. An hCG stimulation test provoked no response in the serum levels of testosterone. Case 1, who was 28 years old at the first visit, received parenteral testosterone and appreciable virilization of the genitalia was noted within a few months. When he married and desired to father a child, the treatment was switched to hCG/hMG combined therapy and spermatozoa appeared subsequently in the ejaculate, although their numbers were low. His wife conceived and delivered a healthy baby girl. Case 2 was a single young man who presented with hypogonadotrophic hypogonadism and hyperprolactinaemia. He was started on hCG injections three times per week and the maturation of his genitalia was advanced rapidly. Semen analyses showed sperm concentration and motility to be within the normal range. Post-treatment GnRH test revealed no improvement in gonadotrophin responses for LH or FSH. In both cases, the hCG test repeated after the gonadotrophin treatment showed normal basal and stimulated testosterone levels. During the course of gonadotrophin treatment in these cases, serum prolactin levels remained elevated, and it is suggested that, in the two cases, the hypothalamo-pituitary function was disturbed by the tumour or its manipulation and the capacity of the pituitary gland to secrete gonadotrophin was impaired. Under such circumstances with persisting hyperprolactinaemia, hCG and/or hCG/hMG combination treatment can induce normal virilization and advance spermatogenesis sufficiently to achieve fertility.

Psychopathological aspects of neuroendocrine diseases: possible parallels with the psychoendocrine aspects of normal aging

Psychological impairments can occur during the course of major endocrine diseases. These impairments range from mild affective-cognitive-behavioral disturbances to frank psychoses. The former are rather specific for each hormonal disorder and disappear with the hormonal correction. The latter, instead, seem to be quite nonspecific and include depression, mania, schizophrenia-like and organic brain syndromes which appear at random in each endocrinopathy, not always regressing with hormonal recovery, and apparently correlating more with the severity than with the nosographic classification of the metabolic disturbances. It is suggested that age-related physiological changes of hormonal and psychological patterns mimic those occurring in neuroendocrine diseases and that, possibly, common brain biochemical changes may underlie the two phenomena.

The effect of ovine prolactin on the epididymal sialic acid concentration in male rats

1. Previous experiments have shown that the level of sialic acid in the epididymis is influenced by factors originating in the testis. 2. To exclude interference from these factors, both orchidectomized and duct-ligated rats were used to study the potential role of prolactin in the epididymis. 3. When ovine prolactin was injected in orchidectomized rats, a dose-related increase in the level of sialic acid was observed in the epididymis. 4. That this action of prolactin is independent of androgen was confirmed by studies using bromocriptine, which decreases circulating endogenous prolactin. 5. The physiological role(s) of epididymal sialic acid production in response to prolactin remain to be established.

Is routine endocrine testing of impotent men necessary?

Endocrine screening of impotent men is performed in an effort to identify a treatable cause of impotence. However, the prevalence of endocrinopathy in this patient population is low. We determined whether any historical or physical findings obtained during the initial office visit would identify a subgroup of patients at risk for endocrinopathy to decrease the cost of endocrine screening. The results of routine endocrine screening of 330 consecutive impotent patients formed the basis of this study. A total of 7 patients (2.1%) had endocrinopathy. Testicular atrophy was observed in 5 of these 7 patients and 6 reported decreased libido. All of the patients with endocrinopathy had either decreased libido or bilateral testicular atrophy. Our results indicate that the cost of impotence evaluation can be decreased by screening only those patients with clinical signs of hypogonadism, that is either decreased libido or bilateral testicular atrophy.

Effects of uncomplicated acute myocardial infarction on biochemical parameters of stress and sexual function

The blood levels of several "stress indicators" (prolactin [PRL], growth hormone [hGH], total catecholamines, and adenosine 3',5'-cyclic monophosphate [cAMP]) were measured in men during the first 2 weeks of uncomplicated acute myocardial infarction (AMI) and during a 3-month follow-up period. PRL levels were significantly elevated during the first day, and hGH was elevated during the week after the AMI. The levels returned to the control baseline values thereafter. The levels of the total catecholamines and cAMP in blood remained normal throughout the study period. Sexual function during the 3-month follow-up was measured in 29 patients, using a specially designed questionnaire. Impotence was found in five patients and decreased libido in four. No correlation was noted between PRL values, the other stress indicators, and sexual dysfunction. A trend toward increased incidence of sexual dysfunction was found among patients with recurrent AMI.

Age-related changes in hormones in impotent men. Jefferson Sexual Function Center

A total of 818 impotent men were evaluated in a multidisciplinary Sexual Function Center for reproductive hormone levels. Data are presented demonstrating an overall rate of endocrinopathy at 19.3 percent. Various age-dependent trends in the incidence of abnormal levels are noted. Hypogonadism as well as hyperpituitarism appear to increase in incidence with increasing age. Hyperprolactinemia, however, seems to be relatively constant in occurrence. Because of the likelihood of detecting endocrine abnormalities, a recommendation is made for routine hormonal screening of all patients complaining of impotence.

Paedophilia and hyperprolactinaemia

The case of a man presenting with paedophilia who has found to be hyperprolactinaemic is described. There is possibly a link between paedophilia and endocrine disorders.

Seminal prolactin and its relationship to sperm motility in men

Semen assessment and levels of serum and seminal plasma prolactin (PRL) were determined in 81 men. In subjects with both normal sperm concentrations and normal sperm motility, the levels of serum and seminal plasma PRL were 14.7 +/- 1.48 and 10.0 +/- 1.05 ng/ml (mean +/- standard error of the mean, SEM, P less than 0.05), respectively. This difference is not observed either in subjects with polyzoospermia with normal sperm motility, or in those with oligozoospermia. Serum PRL was higher in azoospermia and also in subjects with lower levels of seminal citric acid. Seminal plasma PRL was directly related to sperm motility (r = 0.70, P less than 0.01) and inversely related to sperm concentration (r = -0.42 P less than 0.05). Seminal PRL was increased in subjects with higher levels of seminal citric acid and decreased in subjects with lower levels of corrected seminal fructose. Serum and seminal plasma PRL did not change significantly in subjects with different concentrations of serum testosterone.

Neuropeptides and male sexual behavior

Evidence is rapidly accumulating that a number of neuropeptides are involved in the central control of male sexual behavior. This is consistent with their neuroanatomical distribution, i.e., in CNS loci previously implicated in the control of this behavior such as the medial preoptic area, and with recent findings that the peptide content of some of these regions is regulated by testosterone or its metabolites. Most of the work has been done using rats, but relevant human studies have been included whenever such material has been available. At this point there are relatively few studies which directly demonstrate the involvement of peptides in this behavior. Inhibitory and facilitatory actions, however, have been demonstrated following injections of peptides, peptide antisera, or antagonists into the CNS of male rats. Significant new developments include demonstrations that injections of substance P and A-MSH directly into the medial preoptic area can facilitate this behavior, while ventricular injection of an oxytocin antagonist can produce a powerful inhibition. The emerging picture is that GnRH, oxytocin, A-MSH and substance P stimulate, while CRF, beta-endorphin, prolactin, and neuropeptide Y are inhibitory. The inhibitory peptides CRF, beta-endorphin and prolactin are related, as they are released in response to stress. This may be relevant to the low level of sexual motivation in some depressed men. Questions concerning sites of action and mechanisms of action which mediate the behavioral effects which have been demonstrated remain largely unanswered.

Prolactinomas presenting as primary amenorrhoea and delayed or arrested puberty: response to medical therapy

Fourteen patients presented with arrested pubertal development associated with prolactin-secreting pituitary tumours; serum prolactin ranged from 4000-104,300 mU/l in the ten females and 920-68,000 in four males. Skull X-ray showed a markedly expanded pituitary fossa in eight patients. CT scan and/or air encephalography showed macroadenomas in nine, of whom seven had large suprasellar extensions to their tumours, yet only five had complained of headache and only two had visual field defects. All were treated with bromocriptine (7.5-60 mg/day) which lowered prolactin substantially in all and into the normal range in 11 (range less than 60-3090, median 105 mU/l). Puberty thereafter progressed spontaneously in 13, but in one patient, whose prolactin did not suppress completely, menarche could be induced only with clomiphene. Anterior pituitary function improved on bromocriptine. In seven patients with macroadenomas, tumour shrinkage into the pituitary fossa was complete and in two others incomplete shrinkage was followed by transsphenoidal hypophysectomy. Seven patients received pituitary irradiation, six after bromocriptine-induced shrinkage and one after transsphenoidal surgery. At follow-up 6 months to 10 years (median 5 years) after presentation, ten remain on bromocriptine with a suppressed serum prolactin, one has a normal prolactin after surgery, and three are off bromocriptine with residual hyperprolactinaemia (418-4680 mU/l). To date, four females have become pregnant and one male has fathered two children. Prolactinomas are an important, albeit rare, cause of arrested puberty and should therefore be sought. Most patients respond well to bromocriptine, with or without pituitary irradiation.

Drug-induced sexual dysfunction

A large body of data, as well as clinical experience, link prescribed medications and substances of abuse with sexual dysfunction. This review surveys the relevant literature and summarises key points relating various classes of medications and their possible sexual side effects. Surprisingly, there were very few carefully designed, well organised, systematic studies of the effects of medication upon sexual performance. The preponderance of data is in the form of either case studies or collections of patient reports of side effects. As a result, there are great variations in the reported rates of sexual disturbances associated with the administration of a given medication. A further difficulty is the lack of precision in the use of terms which describe the various sexual disorders. A final problem is the almost total lack of data concerning both disordered and normal sexual functioning in females.

Effects of chronic sulpiride-induced hyperprolactinemia on plasma testosterone and its responses to hCG in normal men

To elucidate the effects of sulpiride-induced (300 mg daily) long-term (64 days) hyperprolactinemia on basal and hCG-stimulated plasma testosterone (T), hCG was given to five normal men five times at 2-week intervals (before sulpiride administration and at 2, 4, 6 and 8 weeks). Mean integrated hCG responses of plasma T did not change significantly as compared with baseline. However, mean (+/- SEM) basal plasma levels of T decreased significantly (P less than 0.05) from 1011 +/- 148 ng/dl to 852 +/- 13 at 2 weeks, 520 +/- 53 at 4 weeks, 572 +/- 137 at 6 weeks and 554 +/- 140 at 8 weeks. These results suggest that sulpiride-induced hyperprolactinemia (73.8 ng/ml, the average of mean values obtained at 2, 4, 6 and 8 weeks) for 64 days does not suppress secretion of T in response to hCG in spite of a decrease in basal plasma T concentrations. It is unlikely that the low concentrations of plasma T are due to direct effects of hyperprolactinemia on the testis.

Influences of prolactin upon spermatogenesis and spermatozoa during in vitro fertilization in mice

Hyperprolactinemia, induced by pituitary isografts for 20 weeks in male mice and confirmed by radioimmunoassay using anti-mouse prolactin serum, did not impair spermatogenesis in the testis and maturing processes of spermatozoa in the epididymis. Incubation of freshly obtained epididymal spermatozoa for 90 min in culture media containing various levels of mouse prolactin did not yield any adverse effects on percentage motility rates of epididymal spermatozoa. When the level of mouse prolactin in the preincubation medium for epididymal spermatozoa was 100 ng/ml, the rate of fertilization by these preincubated spermatozoa in the subsequent in vitro fertilization experiment was significantly lowered compared with that observed in controls. However, when the level of prolactin in preincubation media was 10 ng/ml, no significant reduction in the rate of fertilization occurred. The present experiments seem to indicate the existence of some differences in the effects of prolactin on male germ cells until they reach the tail of the epididymis and on the processes of capacitation and/or fertilization by epididymal spermatozoa after they leave the epididymis.

The endocrinology of varicoceles

There is good evidence of an associated abnormality in testicular hormone production and spermatogenesis in some men with varicoceles. This abnormality can be demonstrated with dynamic tests of the hypothalamic-pituitary-testicular axis and by measuring seminal plasma androgen levels. A high proportion of oligozoospermic men who have abnormal hormone profiles will respond favorably to correction of their varicosities. Several oligozoospermic men with varicoceles have normal hormonal profiles. To date, in our unit, none of these men has had an improvement in seminal characteristics after varicocelectomy. This result would suggest that these men have incidental varicoceles. It is not clear what the testicular defect is leading to abnormal spermatogenesis in these men. Clearly, more studies are required in this group of men and in the men with sperm densities greater than 30 X 10(6)/ml, the majority of whom have normal responses to GnRH infusion. More information is needed regarding the intratesticular control of hormone production and spermatogenesis. As our knowledge of the paracrine system within the testis increases, so should our understanding of the mechanisms involved in the association of varicoceles and infertility.

Serum and seminal plasma prolactin concentrations in men with normospermia, oligospermia, or azoospermia

Semen analyses were performed and serum and seminal plasma prolactin (PRL) concentrations were determined in 165 samples from 120 men seen with their wives because of infertility. The mean (+/- standard deviation) serum and seminal plasma PRL concentrations were 6.5 +/- 3.3 and 7.5 +/- 3.1 ng/ml, respectively. The mean concentrations of PRL in serum and seminal plasma were similar in groups of men divided by sperm concentration. Seven men had an increased serum PRL concentration. Three of these 7 men had sperm concentrations less than 20 million/ml and none of these 7 men had an increased seminal plasma PRL concentration. Four men had an increased seminal plasma PRL concentration; the serum PRL concentration, sperm concentrations, and motilities were normal in all 4. No man had a decreased serum or seminal plasma PRL concentration. Increased serum PRL concentrations were found infrequently and the increase was slight (23.2 ng/ml or less). Seminal plasma PRL concentrations were related directly to sperm concentrations and motilities, relationships that were statistically significant.

Hyperprolactinemia and impotence

One hundred impotent men and 15 sexually active male volunteers served as the source for this study. Serum prolactin was estimated in all cases using radioimmunoassay technique. Cases with hyperprolactinemia were treated with bromocriptine for 3 months. Hyperprolactinemia was detected in three patients only (3%), with no findings of pituitary tumors. Treatment with bromocriptine markedly reduced the level of serum prolactin together with improvement of sexual libido and potency. The mere presence of 3 cases only with hyperprolactinemia among 100 impotent subjects suggested that hyperprolactinemia is not one of the main causes of impotence.

The effect of ethanol on prolactin release from pituitary cells in vitro

Exposure to ethanol is recognized to cause reproductive impairment in man and animals. Since elevated levels of prolactin will interfere with normal functioning of the hypothalamic-pituitary-gonadal axis, and since ethanol has been shown by others to lead to increased prolactin secretion in vivo, the present in vitro study was undertaken to determine whether there is a direct effect of ethanol (ETOH) on prolactin release. Prolactin release from anterior pituitary cells maintained in monolayer culture and exposed to either no ethanol or media containing ethanol at concentrations of 50, 100, 200, or 400 mg% was measured at 1, 4, 24, 48, 72 hours in incubation. Ethanol added directly to pituitary cells stimulated prolactin release at all time points examined. Significant stimulation occurred with addition of low and mid-range ethanol concentrations (50-200 mg%); no augmented prolactin secretory response was seen with the highest ethanol concentration used (400 mg%). This pattern of response was maintained throughout the entire 72 hour incubation period. Thus, the effect of ethanol on prolactin secretion is mediated, at least in part, at the anterior pituitary level.