The metabolic clearance rate and origin of plasma dihydrotestosterone in man and its conversion to the 5-alpha-androstanediols

MANAGEMENT OF ENDOCRINE DISEASE Hyperandrogenic states in women: pitfalls in laboratory diagnosis

Measuring total testosterone level is the first-line approach in assessing androgen excess in women. The main pitfalls in measuring testosterone relate to its low concentration and to the structural similarity between circulating androgens and testosterone, requiring accurate techniques with high specificity and sensitivity. These goals can be achieved by immunoassay using a specific anti-testosterone monoclonal antibody, ideally after an extraction step. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) will be commonly used for measuring testosterone, providing optimal accuracy with a low limit of detection. Yet, the pitfalls of these two techniques are well identified and must be recognized and systematically addressed. In general, laboratories using direct testosterone immunoassay and mass spectrometry need to operate within a quality framework and be actively engaged in external quality control processes and standardization, so as to ensure appropriate interpretation irrespective of the particular laboratory. Circulating testosterone is strongly bound to sex-hormone-binding globulin (SHBG), and SHBG levels are typically low in overweight hyperandrogenic patients. Thus, low SHBG may decrease circulating testosterone to normal values, which will mask androgen excess status. One way to avoid this pitfall, awaiting direct free testosterone assays that are yet to be developed, is to measure SHBG and calculate free testosterone. A few other pitfalls will be discussed in this review, including those of adrenal androgen exploration, with the aim of helping clinicians to better handle laboratory investigation of androgen excess disorders in women.

Dihydrotestosterone: Biochemistry, Physiology, and Clinical Implications of Elevated Blood Levels

Benefits associated with lowered serum DHT levels after 5α-reductase inhibitor (5AR-I) therapy in men have contributed to a misconception that circulating DHT levels are an important stimulus for androgenic action in target tissues (e.g., prostate). Yet evidence from clinical studies indicates that intracellular concentrations of androgens (particularly in androgen-sensitive tissues) are essentially independent of circulating levels. To assess the clinical significance of modest elevations in serum DHT and the DHT/testosterone (T) ratio observed in response to common T replacement therapy, a comprehensive review of the published literature was performed to identify relevant data. Although the primary focus of this review is about DHT in men, we also provide a brief overview of DHT in women. The available published data are limited by the lack of large, well-controlled studies of long duration that are sufficiently powered to expose subtle safety signals. Nonetheless, the preponderance of available clinical data indicates that modest elevations in circulating levels of DHT in response to androgen therapy should not be of concern in clinical practice. Elevated DHT has not been associated with increased risk of prostate disease (e.g., cancer or benign hyperplasia) nor does it appear to have any systemic effects on cardiovascular disease safety parameters (including increased risk of polycythemia) beyond those commonly observed with available T preparations. Well-controlled, long-term studies of transdermal DHT preparations have failed to identify safety signals unique to markedly elevated circulating DHT concentrations or signals materially different from T.

Biochemical and physiological aspects of endogenous androgens

This review attempts to give a synopsis of the major aspects concerning the biochemistry of endogenous androgens, supplemented with several facets of physiology, particularly with respect to testosterone. Testosterone continues to be the most common adverse finding declared by World Anti-Doping Agency accredited laboratories, such samples having an augmented testosterone to epitestosterone ratio. Knowledge regarding the precursors and metabolism of endogenous testosterone is therefore fundamental to understanding many of the issues concerning doping with testosterone and its prohormones, including the detection of their administration. Further, adverse findings for nandrolone are frequent, but this steroid and 19-norandrostenedione are also produced endogenously, an appealing hypothesis being that they are minor by-products of the aromatization of androgens. At sports tribunals pertaining to adverse analytical findings of natural androgen administration, experts often raise issues that concern some aspect of steroid biochemistry and physiology. Salient topics included within this review are the origins and interconversion of endogenous androgens, the biosynthesis of testosterone and epitestosterone, the mechanism of aromatization, the molecular biology of the androgen receptor, the hypothalamic-pituitary-testicular axis, disturbances to this axis by anabolic steroid administration, the transport (binding) of androgens in blood, and briefly the metabolism and excretion of androgens.

A highly specific heterologous enzyme immunoassay for 5 alpha-androstane-3 alpha, 17 beta-diol 17-glucuronide (androstanediol-17G) and developmental patterns of urinary androstanediol-17G excretions

We established a highly specific enzyme immunoassay (EIA) for 5 alpha-androstane-3 alpha, 17 beta-diol 17-glucuronide (androstanediol-17G). Rabbit antisera raised against 5 alpha-androstane-3 alpha, 11 alpha, 17 beta-triol 17-glucuronide 11-glutaryl bovine serum albumin and a heterologous tracer of androstanediol-17G conjugated with horseradish peroxidase at the glucuronic acid group were used. The EIA showed excellent specificity: there were no remarkable cross-reactivities with related androgens. The assay range for urine samples was 0.3-30 ng/ml. Recoveries of standards added to samples were 100-108%. Intra-assay and inter-assay coefficients of variation were 2.9-4.4% and 5.7-7.9%, respectively. The EIA was applied to urine samples of 407 males and 322 females to determine developmental patterns and normal ranges of androstanediol-17G excretions in 11 age groups (0 y, 1 y, 2-3 y, 4-5 y, 6-7 y, 8-9 y, 10-11 y, 12-13 y, 14-15 y, 16-17 y, and over 18 y). Urinary androstanediol-17G/creatinine (androstanediol-17G/Cre) ratios in both sexes were high in infancy, tended to decrease during childhood, and began to increase near adolescence. While androstanediol-17G/Cre ratio in girls increased at 8-9 y and reached a plateau during adolescence, that in boys increased at 10-11 y and continued to increase throughout adolescence. Androstanediol-17G/Cre ratios in girls were higher than those in boys at 6-7 y (P < 0.05) and at 8-9 y (P < 0.01). Androstanediol-17G/Cre ratios in boys were higher than those in girls at 12-13 y and at older ages (P < 0.01). These developmental patterns are parallel to age-related changes in androgenicity and serum androstanediol-17G, suggesting that urinary androstanediol-17G/Cre ratio could be a good marker for androgenicity in childhood.

Hormone profiles in young adults with epilepsy treated with sodium valproate or lamotrigine monotherapy

PURPOSE

Treatment with sodium valproate (VPA) may be associated with polycystic ovarian syndrome (PCOS) in some women with epilepsy. By comparing hormone profiles in young adults taking VPA or lamotrigine (LTG) as monotherapy, this study aimed to explore whether a pharmacologic effect of VPA could be responsible for this observation.

METHODS

Hormone profiles in men and women taking VPA (n = 40) or LTG (n = 36) monotherapy for epilepsy were compared. None of the women were receiving hormonal contraception or replacement. Patients gave details of seizure type and frequency, menstrual cycle, and medical and drug history. Body mass index was calculated, and fasting insulin, glucose, cholesterol, triglycerides (TG), high- and low-density lipoproteins, testosterone, dihydroepiandosterone (DHEA), androstenedione, sex hormone-binding globulin (SHBG), free androgen index (FAI), luteinising hormone (LH), follicle-stimulating hormone (FSH), and antiepileptic drug (AED) concentrations were measured.

RESULTS

There were no differences between treatment groups for both sexes in age and seizure control. Only four obese VPA-treated women were hyperinsulinaemic (p = 0.05); three with abnormal menstrual cycles; one with raised testosterone. Testosterone (p = 0.02), FAI (p = 0.03), and TG (p = 0.02) levels were higher, however, in women taking the drug. Obese patients of both sexes (p = 0.01) and VPA-treated men (p = 0.03) had higher insulin concentrations.

CONCLUSIONS

VPA therapy may be associated with subclinical elevation in fasting insulin levels. Testosterone and TG levels were higher in VPA-treated women compared with the levels in those taking LTG. However, only a minority of obese females exhibited biochemical characteristics suggestive of PCOS. Biochemical screening may allow women at risk of developing PCOS to avoid VPA.

Effects of replacing meat with soyabean in the diet on sex hormone concentrations in healthy adult males

A randomised crossover dietary intervention study was performed to evaluate the effects of replacing meat protein in the diet with a soyabean product, tofu, on blood concentrations of testosterone, dihydrotestosterone, androstanediol glucuronide, oestradiol, sex hormone-binding globulin (SHBG), and the free androgen index (total testosterone concentration/SHBG concentration x 100; FAI). Forty-two healthy adult males aged 35-62 years were studied. Diets were isoenergetic, with either 150 g lean meat or 290 g tofu daily providing an equivalent amount of macronutrients, with only the source of protein differing between the two diets. Each diet lasted for 4 weeks, with a 2-week interval between interventions. Fasting blood samples were taken between 07.00 and 09.30 hours. Urinary excretion of genistein and daidzein was significantly higher after the tofu diet (P < 0.001). Blood concentrations of sex hormones did not differ after the two diets, but the mean testosterone:oestradiol value was 10% higher (P = 0.06) after the meat diet. SHBG was 3% higher (P = 0.07), whereas the FAI was 7% lower (P = 0.06), after the tofu diet compared with the meat diet. There was a significant correlation between the difference in SHBG and testosterone:oestradiol and weight change. Adjusting for weight change revealed SHBG to be 8.8% higher on the tofu diet (mean difference 3 (95% CI 0.7, 5.2) nmol/l; P = 0.01) and testosterone:oestradiol to be significantly lower, P = 0.049). Thus, replacement of meat protein with soyabean protein, as tofu, may have a minor effect on biologically-active sex hormones, which could influence prostate cancer risk. However, other factors or mechanisms may also be responsible for the different incidence rates in men on different diets.

Idiopathic hirsutism

Hirsutism, the presence of terminal (coarse) hairs in females in a male-like pattern, affects between 5% and 10% of women. Of the sex steroids, androgens are the most important in determining the type and distribution of hairs over the human body. Under the influence of androgens hair follicles that are producing vellus-type hairs can be stimulated to begin producing terminal hairs (i.e., terminalized). The activity of local 5alpha-reductase (5alpha-RA) determines to a great extent the production of dihydrotestosterone (DHT), and consequently the effect of androgens on hair follicles. While there are two distinct 5alpha-RA isoenzymes, type 1 and type 2, the activity of these in the facial or abdominal skin of hirsute women remains to be determined. Although the definition of idiopathic hirsutism (IH) has been an evolving process, the diagnosis of IH should be applied only to hirsute patients with normal ovulatory function and circulating androgen levels. A history of regular menses is not sufficient to exclude ovulatory dysfunction, since up to 40% of eumenorrheic hirsute women are anovulatory. The diagnosis of IH, when strictly defined, will include less than 20% of all hirsute women. The pathophysiology of IH is presumed to be a primary increase in skin 5alpha-RA activity, probably of both isoenzyme types, and possibly an alteration in androgen receptor function. Therapeutically, these patients respond to antiandrogen or 5alpha-RA inhibitor therapy. Pharmacological suppression of ovarian or adrenal androgen secretion may be of additional, albeit limited, benefit. New therapeutic strategies such as laser epilation or the use of new biological response modifiers may play an important role in offering a more effective means of treatment to remove unwanted hair. Further investigations into the genetic, molecular, and metabolic aspects of this disorder, including only well defined patients, are needed.

Effect of prednisolone on serum and follicular fluid androgen concentrations in women with polycystic ovary syndrome undergoing in-vitro fertilization

Increased androgen concentrations are thought to be detrimental to oocyte quality and reproductive potential. Adjuvant treatment with glucocorticoids has been tried to suppress androgens in women undergoing infertility treatment. In the present study 20 infertile women with polycystic ovary syndrome were prospectively randomized in a placebo-controlled study to receive either placebo or prednisolone 10 mg at night, during standard in-vitro fertilization (IVF) treatment. Serum samples for assays of gonadotrophins, steroids and sex hormone-binding globulin (SHBG) were collected before treatment, at down-regulation, and at oocyte retrieval. Up to five follicles in each ovary were analysed separately regarding follicular fluid and oocytes, the rest according to the clinic's routines. In the placebo group, serum dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulphate (DHEA-S) did not change between down-regulation and oocyte retrieval, whereas adjuvant prednisolone resulted in a significant decrease. In follicular fluid, adjuvant prednisolone resulted in significantly lower concentrations of DHEA-S as compared to placebo, no other significant differences were found. No significant differences were found in embryo characteristics or pregnancy rates between the groups.

Serum levels of androstanediol glucuronide, total testosterone, and free testosterone in hirsute women

OBJECTIVE

To determine the serum levels of androstanediol glucuronide (3 alpha-diol G), total T, and free T in hirsute and nonhirsute women.

DESIGN

Controlled clinical study.

PATIENTS

Hirsute women with oligomenorrhea, hirsute women with regular ovulatory cycles, and nonhirsute women with regular cycles were selected.

MAIN OUTCOME MEASURE

Serum levels of 3 alpha-diol G, total T, and free T were measured in 8 hirsute with oligomenorrhea and 11 hirsute women with regular ovulatory cycles and compared with 20 nonhirsute women with regular cycles (control group). Serum 3 alpha-diol G was also measured during the follicular, periovulatory, and luteal phases in hirsute women with regular cycles.

RESULTS

Serum levels of 3 alpha-diol G did not change during the menstrual cycle, in addition we observed that there was no difference between the levels of 3 alpha-diol G, total T, and free T in hirsute women with regular cycles when compared with normal women. These three serum androgens were elevated only in the hirsute women with oligomenorrhea. Besides, there was better correlation between total T and free T (r = 0.81) than total T and 3 alpha-diol G (r = 0.49) or free T and 3 alpha-diol G (r = 0.66).

CONCLUSION

The findings suggest that serum 3 alpha-diol G does not provide additional benefit as a marker of hirsutism than serum total or free T.

Is plasma 5 alpha-androstane 3 alpha, 17 beta-diol glucuronide a biochemical marker of hirsutism in women?

We investigated whether plasma androstanediol glucuronide (ADG) levels reflect the increased androgenicity in women with idiopathic hirsutism (n = 24) or hirsutism associated with polycystic ovary syndrome (n = 10). We also evaluated whether ADG levels parallel the clinical evolution of the hirsutism during a combined treatment, with cyproteroneacetate (2 mg) and ethinylestradiol (35 micrograms), of women with moderate idiopathic hirsutism. Finally, we investigated if there is evidence for increased conversion of precursors to ADG in hirsutism, by comparing the ADG levels, measured by RIA, to ADG levels obtained by applying the conversion rates of precursors obtained in non-hirsute women. ADG levels were increased in less than half of the patients with mild hirsutism. The clinical cure of hirsutism, which was obtained by the treatment in majority of patients, was accompanied by a significant decrease of plasma ADG levels, but a similar decrease was also observed in the 5 patients who did not respond to treatment. The data show that, although there is evidence for increased conversion of precursors to plasma ADG in mildly hirsute women, the latter is not a reliable parameter of androgenicity. Our data suggest, moreover, that treatment with cyproterone acetate and ethinylestradiol decreases 5 alpha-reductase activity, as indicated by the more important decrease in ADG levels than in the precursors.

Clinical signs of androgen excess as risk factors for coronary artery disease

Women with androgen excess have been found to have higher triglycerides and lower high-density lipoprotein cholesterol concentrations than nonhirsute women and are presumed to be at increased risk of coronary artery disease. However, definitive data linking androgen excess with coronary artery disease is lacking. We evaluated 102 women coming to coronary artery catheterization for signs and symptoms of androgen excess. Hirsutism was found more commonly in those women with confirmed coronary artery disease (chi 2 = 10.11). Waist:hip ratio (an index of android fat distribution) was associated with hirsutism (by ANOVA, F-test) and with coronary artery disease (t-test). The strongest associations were found in older women (aged greater than or equal to 60). Androgen excess in women may signal risk for coronary artery disease.

Estradiol and testosterone metabolism and production in men with prostatic cancer

We recently observed a familial influence on the plasma concentration of sex-steroids and the metabolic clearance in men with prostatic cancer. We have now determined, by isotope dilution techniques, the blood estradiol and testosterone production and clearance rates in men with prostatic cancer and in unrelated controls. Thirty-eight men had a diagnosis of prostatic cancer before the age of 63, and 22 controls matched for age were randomly selected from the general population. None of the patients or controls had received endocrine therapy. The plasma content of testosterone, dihydrotestosterone, estrone, estradiol, 3 alpha-androstanediol glucuronide, dehydroepiandrosterone sulfate, sex-hormone binding globulin, apparent free testosterone concentration, follicle stimulating hormone and luteinizing hormone were not significantly different between the groups. The metabolic clearance and production rates of testosterone were significantly (P = 0.008 and P = 0.013, respectively) higher in patients [447 +/- 26 L/day/body surface area(m2) and 2.21 +/- 0.17 mg/day/m2, n = 38] than in controls [346 +/- 20 L/day/m2 and 1.70 +/- 0.11 mg/day/m2, n = 22]. The PR and MCR of estradiol were not significantly different between patients with prostatic cancer (n = 19) and controls (n = 12). These results indicate that men with prostatic cancer have elevated clearance and production rates of testosterone without an alteration of estradiol production or clearance.

The role of hyperinsulinemia in the pathogenesis of ovarian hyperandrogenism

The evidence that supports the hypothesis that insulin and LH both regulate ovarian androgen production was presented. The most dramatic clinical example of the association between hyperinsulinemia and hyperandrogenism is the HAIR-AN syndrome. Our hypothesis is that, in the HAIR-AN syndrome, the severe insulin resistance causes a compensatory hyperinsulinemia, which stimulates ovarian androgen production if adequate LH is present. The acanthosis nigricans is an epiphenomenon of the syndrome. Acanthosis nigricans is a dermatologic manifestation of severe insulin resistance. In vitro evidence suggests that insulin and IGF-I stimulate androgen production in incubations of human stroma and theca. The stromatropic effects of insulin may sensitize the stroma to the stimulatory effects of LH. In some hyperandrogenic-insulin-resistant women, a glucose load appears to produce an acute rise in circulating androgens. The magnitude of the rise in circulating androgens is proportional to the magnitude of the insulin response to the glucose load. These data suggest that hyperinsulinemia may play a central role in the development of ovarian hyperandrogenism.

Hirsutism

Hirsutism is a common clinical problem. The pathogenesis of hirsutism in most women is not clearly defined. In this review, the characteristic endocrinologic findings in women with hirsutism are described, and the disorder's evaluation and treatment are discussed.

Circulating dihydrotestosterone may not reflect peripheral formation

We compared the blood (PBDHT) and urine (PUDHT) production rate of dihydrotestosterone (DHT) in normal men and women to determine whether peripheral formation was totally reflected in blood. PBDHT was similar when measured at both sites in men (674 +/- 79 vs. 788 +/- 207 SE micrograms/d); however, PUDHT was greater than PBDHT in women (174 +/- 55 vs. 55 +/- 8 micrograms/d, P less than 0.02). Excretion rates of DHT and 3 alpha-androstanediol (3 alpha diol) were similar in both sexes despite major differences in blood levels. However, between sexes large differences were present in 3 alpha diol glucuronide (3 alpha diolG) in both plasma and urine. These observations indicate that peripheral (renal) formation of DHT and probably 3 alpha diol were not accurately determined by measurement of these steroids in blood. The large difference between blood and urine production rates in women suggests an important role of non-testosterone precursors of 5 alpha-reduced steroids. Measurements of 3 alpha diolG may provide more insight into these peripheral events.

Production, clearance, and metabolism of testosterone in men with prostatic cancer

It was previously unknown whether the production and metabolism of testosterone was altered in men with prostatic cancer. We recently observed a familial influence on the plasma concentration of sex steroids in men with the cancer. We have now determined, by isotope dilution techniques, the blood testosterone production and clearance rates and testosterone metabolism to potent androgen metabolites in men with prostatic cancer, their brothers, and unrelated controls. Nineteen men had a diagnosis of prostatic cancer before age 63 (probands), 23 were brothers of these index cases, and nine controls matched for age were selected randomly from the general population. None had received endocrine therapy. The plasma content of testosterone, dihydrotestosterone, sex hormone binding globulin, apparent free testosterone concentration, follicle-stimulating hormone, and luteinizing hormone were not significantly different between the groups. The metabolic clearance rate of testosterone was significantly (P = .04) higher in probands (458 liters/day/body surface area, median) than in controls (306 liters/day/body surface area). The conversion ratios of both testosterone (1.8%) and dihydrotestosterone (16.9%) to 3 alpha-androstanediol were significantly greater (P = .04 and P = .004, respectively) in probands than in controls (0.95%, 7.8%). These results indicate that men with prostatic cancer have elevated clearance rates of testosterone and an increased conversion ratio of testosterone to its potent 5 alpha-reduced metabolites.

Hyperinsulinemia in hyperthecosis of the ovaries

Fasting insulin concentrations and the insulin response to an oral glucose tolerance test were measured in six virilized women with ovarian hyperthecosis and six weight-matched normal women. For comparison, six women with polycystic ovarian disease were also studied. The diagnosis of hyperthecosis was confirmed in all six virilized women by histologic examination of the ovaries. The fasting insulin concentrations were increased in all of the hyperthecosis patients (84 +/- 32 microU/ml). Insulin response to an oral glucose tolerance test was greatly increased (p less than 0.01) in comparison to normal women and women with polycystic ovarian disease. Significant positive correlations were found between peripheral insulin concentrations and ovarian vein testosterone (r = 0.879, p less than 0.02), dihydrotestosterone (r = 0.866, p less than 0.03), and androstenedione (r = 0.992, p less than 0.01) levels. Insulin resistance persisted after removal of the ovaries even though androgen levels returned to normal. These results suggest that a significant degree of insulin resistance exists in women with hyperthecosis and that insulin stimulates ovarian stromal androgen synthesis and thus may play a role in the pathogenesis of ovarian hyperthecosis.

Production and metabolism of dihydrotestosterone in peripheral tissues

The production and metabolism of dihydrotestosterone (DHT) was studied in 10 normal men using constant infusions of [7-3H]-delta 4 -androstenedione (A)/[4-14C]DHT (6 men) or of [7-3H]testosterone (T)/[4-14C]DHT (4 men) with measurement of radioactivity as precursor and product in the brachial artery, and a superficial vein (draining primarily adipose tissue) and deep vein (draining primarily muscle) in the arm opposite to the infusion. The metabolic clearance rates (MCR) were (mean +/- SE) 560 +/- 55, 1620 +/- 80, and 790 +/- 65, 1/day for DHT, A and T respectively. The overall conversions (percent of A or T infused which was measured as DHT in arterial blood) were 2.3 +/- 0.8% and 2.7 +/- 0.5% for A to DHT and T to DHT. Of the DHT entering the adipose tissue 13.8 +/- 3.4% was metabolized and of that entering muscle 5.8 +/- 1.8% was metabolized. On the basis of assumed blood flows, adipose tissue and muscle metabolism each carry out approx. 7-8% of the overall metabolism of DHT. Of the A entering the forearm adipose tissue 1.9 +/- 0.5% was converted to DHT. Extrapolated to the body's adipose tissue, this represents 14% of the total A converted to DHT. Of the T entering the forearm adipose tissue 1.2 +/- 0.3% was converted to DHT. Extrapolated to the body's adipose tissue, this represents 6% of the total T converted to DHT. In three out of six subjects infused with A/DHT and in three out of four subjects infused with T/DHT small gradients indicating conversion of A and T to DHT by tissues drained by the deep vein were found. The mean value for the conversion of A to DHT across the deep vein tissues was 0.84 +/- 0.51% and for T to DHT was 0.28 +/- 0.12%. Both adipose tissue and muscle metabolize DHT but only adipose tissue appears to play a role in the conversion of A and T to DHT.

Familial male pseudohermaphroditism with gynaecomastia due to 17 beta-hydroxysteroid dehydrogenase deficiency. A report of 3 cases

Three sisters with male pseudohermaphroditism due to 17 beta-hydroxysteroid dehydrogenase deficiency are described. On the basis of a 46 XY karyotype and female phenotype all subjects were thought to have the testicular feminization syndrome. At puberty the two older patients developed signs of virilization and gynaecomastia. In these patients the plasma androstenedione level was 4-5 times higher than normal, whilst the plasma testosterone level was low compared to the normal range and, under basal conditions, their plasma androstenedione to testosterone ratio was 20-25 times higher than normal. Interestingly, in the third, prepubertal case, the basal androstenedione to testosterone ratio was normal but became six times higher than normal after hCG stimulation. These data support the diagnosis of male pseudohermaphroditism due to 17 beta-hydroxysteroid dehydrogenase deficiency and underline the diagnostic value of the hCG stimulation test prepubertally.

The effect of infusions of 5 alpha-dihydrotestosterone or estradiol-17 beta on the concentration of some steroids in the human testicular vein and artery

The concentrations of testosterone, 5 alpha-dihydrotestosterone, 5 alpha-androstan-3 alpha, 17 beta-diol, 5 alpha-androstane-3 beta, 17 beta-diol, estradiol-17 beta and testosterone-glucosiduronate were measured in the plasma of the testicular vein and artery simultaneously with the estimation in peripheral venous and arterial plasma 60 min after an infusion of 3000 micrograms dihydrotestosterone (DHT) or estradiol (E2), respectively, in patients undergoing orchiectomy for prostatic cancer. The results were as follows; following infusion of DHT or E2, both steroids were completely metabolized by the testes. After DHT the testicular secretion of E2 was significantly reduced. In peripheral plasma 3 alpha-diol concentration was increased. Following E2 a transient elevation of testosterone in the spermatic vein was observed, whereas a slight decrease of DHT and an increase especially of 3 beta-diol levels occurred. It is assumed that DHT as well as E2 plays a role as intratesticular regulator of steroid synthesis and metabolism.

Familial factors affecting prostatic cancer risk and plasma sex-steroid levels

Whether familial factors affect the frequency of prostatic cancer and the plasma content of sex-steroids was investigated. Brothers (n = 257) of probands (n = 150) diagnosed with prostatic cancer before age 62 years had a fourfold higher risk for developing the disease than men in the general population in the State of Utah and their brothers-in-law (n = 202). Familial factors markedly affected the plasma content of sex steroids (testosterone, dihydrotestosterone, the ratio of testosterone to DHT, sex-hormone binding globulin, and the free fraction of testosterone) in nonendocrinologically treated probands and their brothers and sons and in normal men in the general populations. Index cases and their brothers and sons had a significantly lower mean plasma testosterone content than controls of comparable age. Preliminary data suggest that the metabolic clearance rate of testosterone and the conversion ratio of testosterone to estradiol are relatively high in probands. The observations indicate that familial factors are potent risk factors for the development of prostatic cancer. They also suggest that plasma androgen values in families with prostatic cancer cluster in the lower range of normal and that plasma sex-steroid content is more similar in each brothers with or without prostatic cancer than among nonbrothers.

The effect of endogenous progesterone on serum levels of 5 alpha-reduced androgens in hirsute women

This study was to examine indirectly the effect of endogenous progesterone, a known competitor for 5 alpha-reductase, on androgen metabolism in target organs in hirsute women. Serum levels of progesterone, testosterone (T), androstenedione (A), dihydrotestosterone (DHT) and 5 alpha-androstane 3 alpha 17 beta-diol (3 alpha-diol) and sex hormone binding globulin (SHBG) were assessed serially over a four week period in normal women, six hirsute women with regular menstrual cycles, eight hirsute women with oligomenorrhoea (and presumptive polycystic ovaries) and seven non-hirsute women with oligomenorrhoea. Serum T and A levels were significantly higher than normal in both hirsute and non-hirsute women with oligomenorrhoea, while serum SHBG was significantly lower than normal in the two groups of hirsute women. The calculated free T level was higher than normal in all three groups of patients. DHT levels were not significantly different from normal in any of the three groups of patients. The 3 alpha-diol level showed considerable overlap with normal in all groups of patients and was only significantly higher than normal in hirsute women with oligomenorrhoea (P less than 0.05). There was a small fall in DHT in the late luteal phase of the cycle of those women with a sustained rise in serum progesterone in the second half of the cycle, but no change in serum 3 alpha-diol. These studies suggest that serum 3 alpha-diol may not be as good an indicator of peripheral androgen metabolism in hirsute women as previously reported and that a rise in serum progesterone has only a minimal effect on circulating levels of the active 5 alpha-reduced androgen metabolites. Although in vitro 3 alpha-diol has been shown to be a potent inhibitor of 5 alpha-reductase this casts doubt on its role in this regard in vivo.

Serum levels of sex hormones in vulvar lichen sclerosus, and the effect of topical testosterone

Lichen sclerosus is a chronic cutaneous disorder of unknown cause that most commonly occurs on the vulva in postmenopausal women. Earlier investigations suggested that the affected tissue is reversibly atrophic and that it has normal metabolic potential. The present study was designed to determine whether levels of sex steroid hormones in serum are altered in this disease and how they are affected by topical testosterone, a recognized form of therapy. As compared with normal values for age, serum levels of dihydrotestosterone, free testosterone, and androstenedione were significantly decreased in patients with untreated vulvar lichen sclerosus. Dihydrotestosterone and testosterone levels rose and exceeded normal values after therapy. These results suggest that abnormal enzymatic activity (5 alpha-reductase) may be responsible for this disease and indicate a need for similar studies of the disorder in other locations.

Steroid dynamics in the rabbit

Male rabbits were infused at a constant rate with 3H-androstenedione/14C-estrone (n = 5) or 3H-testosterone/14C-estradiol-17 beta (n = 3) for 3 1/2 hr and blood samples were obtained over the last hour and analyzed for radioactivity as androstenedione (A), testosterone (T), estrone (E1), estradiol-17 beta (E2 beta) and estradiol-17 alpha (E2 alpha). The mean value for the metabolic clearance rate of androstenedione (MCRA) was 85 +/- 10 l/day/kg, which was significantly greater than the mean MCRE1 59 +/- 10 l/day/kg. MCRT, 42 +/- 8 l/day/kg, and MCRE2 beta, 45 +/- 9 l/day/kg were not different. The conversion ratio of androstenedione to testosterone (CRA,T) was greater than CRT,A but for the estrogens, CRE2 beta, E1 was greater than CRE1,E2 beta. CRE2 beta, E2 alpha was greater than CRE1,E2 alpha. The overall aromatization of androstenedione to estrone, the fraction of 3H-androstenedione infused into the blood and measured as 3H-estrone in blood [( rho]A,E1BB) was 0.0005 +/- 0.0001 and for [rho]T,E2 beta BB was 0.0012 +/- 0.0006. In the rabbit both sex hormone binding globulin (SHBG) and albumin binding may effect the MCRs, and peripheral aromatization of androgens occurs to a far lesser degree than in humans and primates.

Male pseudohermaphroditism due to 17 beta-hydroxysteroid dehydrogenase deficiency: studies on the natural history of the defect and effect of androgens on gender role

Studies within the Arab population in Israel revealed 25 pseudohermaphrodites due to 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) deficiency. Twenty-three individuals, presently living in the Gaza strip, belong to a very large inbred kinship which extends over 8 generations. All affected subjects (46, XY) were born with mild to moderate degrees of ambiguity of an apparently normal-looking female genitalia and therefore were reared as girls. In childhood, genital abnormalities consisted of a clitoral-like phallus surrounded by a chordee, non-fused labial-scrotal folds and a urogenital sinus. The testes were in the inguinal canals, or rarely, in the labial-scrotal folds. Wolffian structures were normally differentiated while Mullerian structures were absent. At puberty, subjects developed a male body habitus with abundant body hair and beard. Gynecomastia was absent. The phallus and testes enlarged to adult proportions while the prostate remained small. Together with the physical change from girls to boys they developed a male identity having erections and ejaculations, which in 7 cases led to the spontaneous adoption of a male gender role. In adults the hormonal abnormalities consisted of greatly elevated delta 4-androstenedione (delta 4) (350-1267 ng/dl) associated with subnormal testosterone (T) levels (0.9-3.1 ng/ml). Dihydrotestosterone (DHT) levels, with the exception of 1 patient, were relatively low in all cases (27-35 ng/dl). Children had low levels of delta 4, T and DHT, which were normal for age. Although from puberty on there was a significant rise of the 3 androgens, delta 4 always remained extremely elevated and T and DHT relatively low when compared to normal controls. Dexamethasone failed to suppress the androgen pattern while HCG augmented the defect, making the diagnosis possible in 2 prepubertal children. Dehydroepiandrosterone (DHEA) and 17-hydroxyprogesterone (17-OHP) levels were normal or moderately elevated. Estradiol (E2) levels were normal in children and all but 2 adults, who had high levels. LH and FSH levels were very high after puberty, but normal before. However, there was an overresponse to LHRH in all age groups. The contrast between the lack of intrauterine virilization of the external genitalia in fetuses with 17 beta-HSD deficiency versus the marked masculinization that occurs after puberty still remains a puzzling phenomenon. It is conceivable that the postpubertal development of a male phenotype with change of gender identity and role occurs due to the joint effect of delta 4, T and DHT, even though secreted in inadequate proportions. Thus masculinization in these individuals is a slow process requiring a longer period of time than that of normal puberty to be completed.

A comparison of androgen production and clearance in hirsute and obese women

Virilization in women is associated with increased production of testosterone as well as a variety of androgenic prehormones, including androstenedione, androstenediol, DHEA, DHEA-sulfate, dihydrotestosterone and androstanediol. Of these hormones, it is likely that testosterone is the androgen which initiates a series of androgen-receptor mediated events resulting in stimulation of 5 alpha reductase in the skin and hair follicles, producing dihydrotestosterone locally. The metabolism of testosterone to dihydrotestosterone within the hair follicle results in increased clearance of testosterone, however at the expense of hair follicle stimulation. Increased 5 alpha reductase of the skin and hair allows other prehormones to be metabolized to dihydrotestosterone and androstanediol, further stimulating the hair follicle (multiplier effect). In obese women, androgen production rates are elevated and SHBG levels are depressed, in many cases to the same magnitude as that observed in hirsute women. Increased androgen production rates in obesity, however, are associated with major increases in clearance rates of these androgens. Resultant androgen blood levels are even lower than observed in the non-obese population. It appears likely that adipose tissue is the site of the increased clearance rates and metabolism of prehormones to dihydrotestosterone and androstanediol. A delicate balance likely exists between production and clearance of these biologically active hormones. Minor aberrations in this balance may result in the increased incidence of hirsutism seen in the obese female population.

Male gonadal function in coeliac disease: 2. Sex hormones

Hypogonadism, infertility, and sexual dysfunction occur in some men with coeliac disease. We have measured plasma testosterone, dihydrotestosterone, sex-hormone binding globulin, oestradiol, and serum luteinising hormone in 41 men with coeliac disease and have related these findings to jejunal morphology, fertility, semen quality, and sexual function. To determine the specificity of these observations in coeliacs we also studied 19 nutritionally-matched men with Crohn's disease, and men with chronic ill-health due to rheumatoid arthritis and Hodgkin's disease. The most striking endocrine findings in untreated coeliacs were increased plasma testosterone and free testosterone index, reduced dihydrotestosterone (testosterone's potent peripheral metabolite), and raised serum luteinising hormone, a pattern of abnormalities indicative of androgen resistance. As jejunal morphology improved hormone levels appeared to return to normal. This specific combination of abnormalities was not present in any of the disease control groups and, to our knowledge, androgen resistance has not been described previously in any other non-endocrine disorder. Plasma oestradiol concentration was modestly raised in 10% of coeliacs and 11% of patients with Crohn's disease. Unlike plasma androgens and serum luteinising hormone in coeliacs, plasma oestradiol was not clearly related to jejunal morphology. Androgen resistance and associated hypothalamic-pituitary dysfunction appear to be relatively specific to coeliac disease and cannot be explained merely in terms of malnutrition or chronic ill-health. In addition, our findings suggest that this endocrine disturbance may be related to sexual dysfunction in coeliac disease but its relationship to disordered spermatogenesis in this condition has not been clearly established.

Age-related changes of plasma steroids in normal adult males

Plasma cortisol, 17-hydroxyprogesterone (17-OH-P), testosterone (T), 5 alpha-dihydrotestosterone (DHT, estrone (E1) and estradiol (E2), were measured in 94 normal adult men aged between 20-99, using RIA methods after chromatographic separation of steroids on Sephadex LH-20 columns. All plasma steroids except 17-OH-P, were age dependent: cortisol, testosterone and DHT decreased significantly with age, whereas estrone and estradiol were significantly increased in elderly men. Cortisol, testosterone, T/DHT ratio and estradiol levels were significantly correlated with age. The age related changes of plasma steroids in elderly men, were suggestive of decreased cortisol secretion, and decreased testicular function with increased peripheral conversion of androgens into estrogens. Testosterone was positively correlated with its precursor (17-OH-P) and respectively its peripheral metabolites (DHT and E2). The negative correlation between estrone and 17-OH-P found in elderly men, suggested that increased estrogen level in aging males may be considered able to inhibit the testicular androgen production.

Urinary unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol in patients with prostatic tumours

A sensitive and reliable radioimmunoassay (RIA) for urinary unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol is described. The mean overall recovery of unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol was found to be 57.4%. The sensitivity of the assay was 79 fmol per assay tube and the intra and inter-assay variations ranged between 7.2% and 11.4%. The mean +/- SEM for the concentration of this androgen in the urine of normal men was 339.6 +/- 66.8 nmol/24 h. The corresponding values for patients with benign prostatic hypertrophy (BPH) and carcinoma of the prostate (Ca) were 297.8 +/- 44.7 and 1592.1 +/- 622.7 respectively. The mean value for Ca patients was significantly higher than either BPH (p less than 0.05) or normal subject (p less than 0.02), suggesting a differential urinary excretion pattern for unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol between BPH and Ca patients. It is concluded that the combined measurement of this androgen in the plasma and urine provides a more accurate assessment of the profile of this hormone than a single plasma estimation.

Clinical and hormonal studies in hyperthecosis of the ovaries

Endocrine studies were performed in five women with ovarian hyperthecosis. Measurement of testosterone (T), dihydrotestosterone (DHT), androstenedione (A), 17 alpha-hydroxyprogesterone (17-OHP), progesterone (P), estradiol (E2), and estrone (E1) in the peripheral and ovarian vein serum obtained simultaneously at the time of surgery indicated that the hyperthecotic ovaries secreted large amounts of potent androgens T and DHT. There was a less marked increase in A secretion. Peripheral P and 17-OHP levels were elevated, with a significant peripheral ovarian gradient. E1 comes entirely from peripheral conversion, while at least a portion of E2 comes from direct secretion from the ovaries. Circulating FSH and LH levels were low or normal. The gonadotropin response to LH-RH was in the normal range. No patient ovulated with Clomid treatment. The hirsutism did not improve with ovarian suppression with birth control pills, possibly because of the absence of tonic elevation of LH. The hypothalamic pituitary physiology in hyperthecosis is different from that in polycystic ovarian disease.

Effects of chronic neuroleptic therapy on human PRL secretion and testicular function

Correlation between secretion of testicular steroids and plasma prolactin (PRL) levels, before and during bromocriptin treatment, was studied in 20 psychiatric patients under neuroleptic therapy for two years or longer. Eleven of them were under additional treatment with antiparkinson drugs (AP group). Plasma PRL, testosterone (T), 5 alpha dihydrotestostérone (DHT), 17 beta-estradiol (E2), 17 alpha OH-progestérone (17 alpha OHP), and dehydroepiandrosterone-sulfate (D-S) were measured by specific RIA both at basal level and in response to testicular stimulation by hCG. Mean basal PRL levels were normal in the patients under neuroleptic treatment along (Ne group), and slightly elevated in the AP group. In the Ne group, an unexpected, significant increase occurred in mean plasma PRL during the hCG stimulation, before bromocriptine treatment. Mean basal steroid levels were normal in both groups. The testicular responses to hCG, as reflected by the T, E2, 17 alpha OHP, and DHT mean plasma levels, were within the normal ranges in the AP group; in the Ne group, however, T and DHT displayed a subnormal mean increase, while E2 and 17 alpha OHP responses were within the normal range. These results suggest that some modifications of the enzymatic activity for testicular steroidogenesis could be induced in the patients under neuroleptic treatment alone. Moreover, a significant reverse correlation was found between PRL and T basal in both group; this correlation disappeared during the bromocriptine treatment.

Interaction of prolactin and testosterone in the human prostate

Three experiments were performed to determine whether human prolactin (hPr) affects prostatic uptake and metabolism of testosterone (T). 1) Patients with prostatic cancer were infused twice with radio-labelled androgens, the first time with basal hPR, the second time with oral thyrotrophin-releasing hormone (TRH)-elevated hPr. In 5/7, significant increases in metabolic clearance of dihydrotestosterone (DHT) and in conversion of T to DHT accompanied increased hPR. 2) The incorporation of labelled T into minced benign prostatic hypertrophy (BPH) tissue from subjects with high (40 ng/ml) hPR was measured and was found to be more than twice the uptake into tissue from those with low hPR (6.5 +/- 1.9 ng/ml). 3) Uptake and metabolism in vivo of a bolus of 3H-T by BPH and carcinomatous prostates was measured and was far greater in subjects whose hPR was elevated by chlorpromazine than in untreated controls. It is concluded that prolactin increases prostatic uptake and metabolism of T. It is suggested that the best management of prostatic cancer should include depletion of prolactin as well as androgen.

[Not Available]

Summary In human beings, androgen metabolism plays an important role in mediating the action of male hormones upon target structures of the skin. First, human skin is capable of transforming inactive steroids supplied through the blood, such as androstenedione and dehydroisoandrosterone, into the active androgen testosterone. Second, human skin is able to reduce testosterone to 5alpha-DHT, an essential prerequisite, during embryogenesis, for the male differentiation of target structures derived from urogenital sinus. At puberty, hair growth in sexual areas of skin also requires the transformation of testosterone to DHT. Regulation of 5alpha-reductase activity varies according to the anatomical site of the enzyme. In foetuses, 5alpha-reductase activity present in tissues derived from the urogenital tract does not seem to be androgen-dependent, since it is acquired before the onset of testosterone secretion by foetal testis. By contrast, the enzyme that mediates development of certain secondary sex characteristics, such as pilosebaceous gland activity in sexual areas, is clearly androgen-dependent, since it is absent before puberty and in persons with hypogonadism. These differences in the control of the 5alpha-reductase activity mediating the appearance of either primary or secondary sex characteristics are important and may explain the differences in 5a-reductase activity observed in adult skin of both sexes derived from different sexual areas. In addition, the knowledge of androgen relation to the skin is necessary in order to understand the action of the anti-androgens, particularly the compounds which may be used by topical administration.

The diagnosis and management of intersex

The patient whose genitalia are ambiguous or are inappropriate for the assigned sex presents the physician with a set of problems requiring a thorough grasp of sexual differentiation, development and function. Although several reviews have covered various aspects of these matters, these texts do not cover recent advances in understanding normal and abnormal sexual development nor do they provide an integrated guide to the management of intersex cases. Our objectives are to show the clinical relevance of recent advances in understanding the determinants of normal and abnormal sexual differentiation, to indicate the improved diagnostic procedures now available and to provide specific guidelines for optimal case management in the light of current medical knowledge and psychological and ethical understanding.

The pathogenesis of benign prostatic hyperplasia

Development of prostatic hyperplasia is an almost universal feature of the aging man and dog, and in both species the process develops only in males with intact testes. As the result of studies of plasma hormone levels as a function of age, measurements of the concentration of androgen and of androgen receptor proteins within the prostate, and studies of the effects of the administration of various hormones on growth of the prostate in the castrated dog, it is possible to provide a working hypothesis as to the pathogenesis. Dihydrotestosterone accumulation within the gland serves as the hormonal mediator for the hyperplasia in both species; the accumulation probably occurs in part because of decreased catabolism of the molecule and in part because of enhanced intracellular binding of the molecule. The process is accelerated by estrogen, which enhances the level of the androgen receptor in the gland; increase in the androgen receptor allows for androgen-mediated growth even in the face of declining androgen production in advanced age. On theoretic grounds the therapeutic implications of this model are exciting; several potential medical treatments may be feasible that do not involve a chemical castration.

Androgen and estrogen conversion rations in aging women

Androgens and estrogens labeled with 3H- and 14C- have been infused at constant rates into postmenopausal women whose ages ranged from 45--90 yr, and who were 1--40 yr postmenopausal. The conversion ratios (ratio of concentrations of radioactivity as infused precursor to product steroid) for interconversions of androstenedione to testosterone, for the conversions of androstenedione and testosterone to dihydrotestosterone and for the interconversions of the estrogens were calculated. There was no trends in the conversion ratios with age and the mean values for these ratios in these postmenopausal women did not differ significantly from their respective values in a group of normal, healthy, reproductive-aged women. Our data are compatible with the conclusion that the overall activities of certain 17 beta-dehydrogenases and 5 alpha-reductases do not decrease appreciably with age.

New aspects of androgens, prolactin, and ACTH interaction in men

Some endocrine effects of prolactin (PRL), ACTH, and corticosteroids in testicular function were evaluated by measuring, in normal men, the effects of short-term experimental stimulation and suppression of either plasma PRL levels or adrenal function on plasma androgen profile. PRL levels were increased by administration of metoclopramide or sulpiride or suppressed with bromocryptine. Long-acting testosterone (T) was injected at 8 a.m. on one day in a control period and during a 9-day period of metoclopramide administration. PRL increase was accompanied by a rise in plasma 17-hydroxyprogesterone and T, whereas PRL suppression induced an increase in 5 alpha-dihydrotestosterone (DHT) plasma levels. Peripheral converions of T into DHT and androstenedione, noted after T injection, decreased during concomitant metoclopramide administration. Plasma testicular androgen levels were lowered after long-acting ACTH injections as well as after 24-hr cortisol administration, but the metoclopramide-induced PRL increase appeared to prevent the suppressive effects of ACTH on plasma T. A low-dose dexamethasone treatment did not modify testicular androgen levels. Experimentally induced hyperprolactinemia may have a stimulatory effect on testicular androgen secretion as well as a lowering action on 5 alpha reduction and oxidative T metabolism in man. On the other hand, ACTH-induced androgen suppression seems to be mediated through high circulating levels of corticosteroids; furthermore, PRL and corticosteroids might have reciprocal influences that modulate their effects on testicular function.

Serum dihydrotestosterone in patients with benign prostatic hypertrophy

Serum dihydrotestosterone (DHT) and testosterone were measured by radioimmunoassay in 24 normal men aged 60 to 80 years and in 25 patients with benign prostatic hypertrophy in the same age range. There was a significant increase in the level of dihydrotestosterone in patients with prostatic hypertrophy but no significant difference was found between the testosterone levels of the 2 groups. The scatter of the individual values for DHT indicated that this measurement has little practical clinical application in the diagnosis of prostatic hypertrophy. It is suggested that the increase in DHT may be due, at least in part, to a prostatic contribution to the circulating level and the relevance of this observation in relation to the aetiology of benign prostatic hypertrophy is discussed.

Study on the binding of dihydrotestosterone, testosterone and oestradiol with sex hormone binding globulin

Saturation studies on sex hormone binding globulin (SHBG) were performed with increasing levels of the three steroids: dihydrotestosterone (DHT), testosterone (T) and oestradiol (E2) in normal female sera. The curves obtained showed the clearly increasing SHBG affinity for E2, T and DHT, respectively. With T as saturating ligand, the mean values of SHBG binding capacity in normal and pathological sera, expressed as 10(-8) M SHBG were, for normal women, 5.87 +/- 0.2, for normal men, 3.69 +/- 0.1 and for hirsute women, 5.05 +/- 0.2. In hirsutism, SHBG levels were measured together with T and DHT levels. Hyperandrogenia was often better reflected by the T/SHBG ratio than by T levels alone. SHBG binding capacity, measured in pregnancy from the 7th to the 40th week, increased progressively as far as the 30th week. Values up to 5 times those of the mean value of the cycle were observed at the end of pregnancy. Variations in DHT, T and E2 binding as functions of SHBG concentrations, were also studied by adding a constant amount of each steroid to increasing SHBG concentrations in serum. DHT showed the greatest binding capacity, followed by T and then E2. Since the unbound fractions of T and DHT are believed to be biologically active, and since T and DHT are more sensitive than E2 to SHBG variations, the results obtained further support the hypothesis that SHBG plays an important role in the sex steroids balance.