Dihydrotestosterone and 3 alpha-androstanediol dynamics in the normal, involuted, and hyperplastic canine prostate

Perfusion of canine prostatic tissue with [1, 2-3H] 5 alpha-androstane-3 alpha, 17 beta-diol and [4-14C] dihydrotestosterone and the measurement of the isotopic concentrations at the steady state were used to calculate the metabolic dynamics of these steroids by prostatic tissue obtained from normal, castrated or androgen-treated dogs. From the results it was concluded that: Entry of both steroids into the tissue was similar, and no saturation was observed with increasing concentrations of these androgens in the perfusion medium. In contrast, the entry of both steroids was reduced when the perfusion buffer was replaced with diluted plasma. Dihydrotestosterone in prostatic tissue was present in a diffusible form, whereas 3 alpha,17 beta-androstanediol was not. The conversion of 3 alpha, 17 beta-androstanediol to dihydrotestosterone was always higher than the conversion of dihydrotestosterone to 3 alpha, 17 beta-androstanediol; thus, the oxidative pathway was favored. The entry and uptake of both androgens was greatly reduced in those prostates excised from castrated dogs. The uptake of dihydrotestosterone by normal prostatic tissue was 3- to 6-fold higher than the uptake of 3 alpha, 17 beta-androstanediol. However, higher intratissular concentrations of dihydrotestosterone were obtained by increasing the concentration of 3 alpha, 17 beta-androstanediol perfused over that observed by increasing the concentration of dihydrotestosterone perfused. In the hyperplastic tissue, the entry, uptake and metabolism of the two androgens were similar to those observed in the normal gland, but their intratissular concentrations were found to be higher.     

Purification and characterization of testosterone-binding globulin of canine serum.

Testosterone-binding globulin (TeBG) of canine serum was purified to apparent homogeneity by affinity chromatography on testosterone-17 alpha-ethynylcarboxyaminoethyl-Sepharose 4B followed by hydroxyapatite column chromatography. Canine TeBG was a glycoprotein containing 5.5% carbohydrates. Equilibrium sedimentation analysis in the presence and absence of 6 M guanidine hydrochloride gave molecular weights of 40,000 and 76,000, respectively, suggesting that native TeBG consists of two subunits. Equilibrium dissociation constants at 0 degrees C for testosterone and dihydrotestosterone were estimated to be 5.58 x 10(-8) M and 1.43 x 10(-8) M, respectively, and the number of binding site per native molecule was approximately unity for both androgens. Canine TeBG had virtually no affinity for estradiol, progesterone, or cortisol. Canine TeBG did not cross-react with a rabbit antiserum raised against bovine TeBG.     

Androgens and oestrogens in normal and cryptorchid stallions.

Total androgens, testosterone and total oestrogens were measured in twenty-one intact, nine unilaterally cryptorchid, three bilaterally cryptorchid stallions and four geldings. Total oestrogens were significantly higher (P less than 0-005) and total androgens significantly lower (P less than 0-05) in the bilateral cryptorchid compared to other groups. There was a significant (P less than 0-025) day and night variation in total androgen levels. Thyroidectomized and intact animals showed a marked decrease in total androgen as well as testosterone levels during the winter period thus showing an effect of season on androgenic function of the testis. Disappearance rate of total and androgens following castration was extremely rapid and levels were undectable within 12 hr. Sexual stimulation appeared to increase total androgen levels. Testosterone, androstenedione, dihydrotestosterone, androstandiols, and androstenediol were identified in spermatic vein blood. Dihydrotestosterone was measured in fluid from the cauda epididymidis.     

Effect of castration monotherapy on the levels of adrenal androgens in cancerous prostatic tissues

The mechanism accounting for the development of castration-resistant prostate cancer (CRPC) remains unclear. Studies in CRPC tissues suggest that, after androgen deprivation therapy (ADT), the adrenal androgens may be an important source of testosterone (T) and 5-alpha dihydrotestosterone (DHT) in CRPC tissues. To clarify the role of adrenal androgens in the prostatic tissues (prostatic tissue adrenal androgens) during ADT, we developed a high sensitive and specific quantification method for the levels of androgens in prostatic tissue using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Human prostatic tissues were purified using mixed-mode reversed-phase, strong anion exchange Oasis cartridges (Oasis MAX). Analysis of steroids was performed using LC-MS/MS after picolinic acid derivatization. The validation tests showed that our method of quantitative analysis was precise and sensitive enough for the quantification of dehydroepiandrosterone (DHEA), androstenedione, androstenediol, T, and DHT in the prostatic tissue. The levels of adrenal androgens in prostate cancer tissues after ADT were similar to those in untreated PCa. Especially, DHEA was the most existing androgen precursor in PCa tissues after ADT. The levels of DHEA were high in PCa tissues, irrespective of ADT. We assumed that DHEA played a significant role in the synthesis of T and DHT in PCa tissues after ADT.     

5 Alpha-reductase and 3 alpha-hydroxysteroid dehydrogenase activities in isolated canine prostatic epithelial cells

Kinetic parameters of two enzymes, 5 alpha-reductase and 3 alpha-hydroxysteroid dehydrogenase, have been calculated for freshly isolated canine prostatic epithelial cells separated into secretory and non-secretory cells on the basis of their density in Percoll gradients. For 5 alpha-reductase, a Km value of 3 X 10(-6) M was obtained in both epithelial cell types, and similar Vmax values of 1.7 X 10(-12) and 1.9 X 10(-12) moles of dihydrotestosterone formed/min/10(6) cells (P greater than 0.50) were calculated in secretory and non-secretory cells, respectively. The Km of 3 alpha-hydroxysteroid dehydrogenase (dihydrotestosterone----3 alpha-androstanediol) varied between 2.2 and 2.8 X 10(-6) M (P greater than 0.50) with respective Vmax's of 9 and 24 X 10(-12) moles of 3 alpha-androstanediol formed/min/10(6) cells (P less than 0.005) in secretory and non-secretory cells. For the reverse reaction, that is the transformation of 3 alpha-androstanediol to dihydrotestosterone, the Km's obtained were 0.4 and 0.5 X 10(-6) M (P greater than 0.50) with Vmax's of 14 and 19 X 10(-12) moles of dihydrotestosterone formed/min/10(6) cells (P less than 0.50) in secretory and non-secretory cells, respectively. Vmax values for 3 alpha-hydroxysteroid dehydrogenase are 10-fold higher than the ones for 5 alpha-reductase. Moreover, Km values for the reaction 3 alpha-androstanediol----DHT are 5-fold lower than those calculated for the reverse reaction and for 5 alpha-reductase. This could explain why the major metabolic pathway in the canine prostate gland is the conversion of 3 alpha-androstanediol to dihydrotestosterone.     

Increase in plasma 5 alpha-androstane-3 alpha,17 beta-diol glucuronide as a marker of peripheral androgen action in hirsutism: a side-effect induced by cyclosporine A

Dose-dependent hypertrichosis is a common dermatological side-effect affecting the majority of patients treated with cyclosporine A (CSA). Previous studies have not demonstrated the influence of CSA on specific sex hormone levels. The aim of this study is to investigate whether CSA increases the activity of 5 alpha-reductase, an enzyme which transforms androgens into dihydrotestosterone in peripheral tissues. The metabolite which best reflects this activity is 5 alpha-androstane-3 alpha,17 beta-diol glucuronide (Adiol G). The study was carried out on 49 insulin-dependent diabetes patients participating in the double-blind "Cyclosporine-Diabète-France" clinical trial, of which 28 were treated with CSA (16 males and 12 females), and 21 received only placebo (10 males and 11 females). All patients underwent extensive clinical and laboratory evaluations prior to and during the present study. In addition to Adiol G, testosterone (T), dehydroepiandrosterone sulfate (DHEA S) and sex hormone-binding globulin (SHBG) were assayed. Levels of Adiol G increased significantly in CSA-treated groups: males, 11.86 +/- 2.58 vs 7.83 +/- 2.30 nmol/l; females, 4.48 +/- 2.70 vs 2.10 +/- 1.22 nmol/l; P less than 0.02 (comparison of means). There were no significant differences in this parameter before and during treatment in either the male or female placebo groups (paired t-test). During the treatment period, T, DHEA S, SHBG and the T/SHBG ratio did not significantly change with respect to their baseline values in any of the groups studied (comparison of means). Comparison (using paired t-test) showed a significant increase of DHEA S in CSA-treated groups: males, delta = 3.08 +/- 3.33 nmol/l, P less than 0.01; females, delta = 0.98 +/- 1.13 nmol/l, P less than 0.05. In conclusion, it is possible that CSA induces hypertrichosis or hirsutism by increasing 5 alpha-reductase activity in peripheral tissues. Nevertheless the role of increased DHEA S as a possible Adiol G precursor cannot be excluded.     

Pituitary-gonadal axis before puberty: evaluation of testicular steroids in the male rat

Orchidectomy was performed on 26-day-old rats via a single midscrotal incision following which 1 of 6 steroids was administered subcutaneously twice daily for 7 days. Each hormone treatment set had its own controls both castrate and intact. Levels of serum LH and FSH were measured by radioimmunoassay. It was found that LH was suppressed to intact levels by testosterone or its active metabolites at doses within the "physiologic dosage range" (equivalent in biological activity to endogenously secreted androgens). FSH suppression with androgens occurred at considerably higher doses; only testosterone could maintain FSH at intact levels with a physiologic dosage. Both 5alpha-dihydrotestosterone, and 3alpha-androstanediol suppressed LH well and FSH partially; 3beta-androstanediol and fluoxymesterone were ineffective over the same dosage range. Estradiol suppressed both LH and FSH. It was concluded that LH is more easily suppressed than FSH by androgens, that there is poor correlation between biologic potency and their gonadotropin-suppression ability, and that testosterone is almost certainly not the final active intracellular androgenic hormone. It was suggested that while a small amount of testicular androgen can maintain the low levels of LH, complete control of FSH secretion may require conversion of testosterone to estrogens.     

Urinary 5 alpha-androstanediol and 5 beta-androstanediol measurement by gas chromatography after solid-phase extraction and high-performance liquid chromatography

Urinary androstanediol measurement, often in association with other androgens, is commonly used to support the clinical diagnosis of idiopathic hirsutism. In addition, androgen excess has been shown to be the endocrine abnormality which characterizes patients with breast cancer. We recently developed a method for the measurement of urinary testosterone employing solid-phase extraction and HPLC purification before quantitative measurement by gas chromatography. In the present report we verify the feasibility of the method for the simultaneous measurement of 5 alpha-androstane-3 alpha,17 beta-diol and 5 beta-androstane-3 alpha,17 beta-diol in addition to testosterone in the same urine sample. The mean recovery for the whole procedure was 89.8% for 5 alpha-androstane-3 alpha,17 beta-diol and 87.8% for 5 beta-androstane-3 alpha, 17 beta-diol. The estimates of the coefficients of variation were 4.9% (95% confidence limits: 3.9-6.5%) and 3.9% (95% confidence limits: 3.1-5.2%), respectively. Accuracy was evaluated by standard addition and dilution assays and a linear relationship was found between expected and observed values (r2 = 0.997 for 5 alpha-androstane-3 alpha,17 beta-diol and r2 = 0.999 for 5 beta-androstane-3 alpha,17 beta-diol). The method is rapid, effective and suitable for the measurement of testosterone, 5 alpha-androstanediol and 5 beta-androstanediol in the same urine sample.     

Steroid production from 17alpha-hydroxypregnenolone and dehydroepiandrosterone by human granulosa cells in vitro.

Granulosa cells were aspirated 3--4 h before the expected time of ovulation from 10 follicles of 4 patients treated with gonadotrophins: 4 of the follicles were immediately preovulatory. The granulosa cells were cultured for 10 h with 17alpha-hydroxypregnenolone or dehydroepiandrosterone and samples of medium removed at 3 and 10 h were assayed for 6 steroids. Granulosa cells were unable to synthesize androgens from endogenous substrate or undertake conversions via the delta5 pathway, but cells from all follicles were capable of aromatizing exogenous androgens to oestrogens although this capability was reduced in cells from follicles beginning to luteinize. Granulosa cells from preovulatory follicles synthesized more progesterone from endogenous substrate than cells from follicles which had not begun to luteinize. The results provide further support for the two-cell theory of oestrogen biosynthesis whereby granulosa cells aromatize androgens which are synthesized by the thecal cells in vivo.     

Effects of ethanol on steroid profiles in the rat testis

The effects of ethanol on the concentrations of steroids in testis was studied in adult rats. Testosterone, seven of its potential precursors, three of its metabolites, and estradiol were analyzed by gas chromatography-mass spectrometry of samples from testes removed 2 h after intraperitoneal administration of ethanol, 1.2 g/kg body weight. The same analyses were made on samples from control rats. Ethanol gave a marked increase of all 3 beta-hydroxy-delta 5 steroids analyzed: pregnenolone (60%), 17-hydroxypregnenolone (480%), dehydroepiandrosterone (430%) and 5-androstene-3 beta, 17 beta-diol (60%). This resulted in highly significant increases of the 3 beta-hydroxy-delta 5/3-oxo-delta 4 steroid ratios for all steroid couples analyzed. An analogous increase of the ratio between 5 alpha-androstane-3 beta, 17 beta-diol and dihydrotestosterone was also observed, whereas the ratio between androstenediol and dehydroepiandrosterone was decreased by ethanol. The concentration of estradiol was not affected. The results indicate that moderate doses of ethanol inhibit the conversion of 3 beta-hydroxy-delta 5 to 3-oxo-delta 4 steroids. This may be one mechanism by which ethanol decreases the production of testosterone.     

Metabolism of adrenal androgens by human endometrium and adrenal cortex

The enzyme 17 beta-hydroxysteroid dehydrogenase (17OHSD) was studied in human endometrium and adrenal cortex with respect to the metabolism of 5-androstene-3 beta,17 beta-diol (androstenediol) and dehydroepiandrosterone (DHA). The aim was to provide further information concerning the origin and biological significance of these androgens in endometrium, particularly the increased concentrations of the secretory phase and to compare the characteristics of the enzyme in the two tissues. In both endometrium and adrenal cortex the metabolism of androstenediol to DHA was linear with time and increasing enzyme concentration. The preferred cofactor was NAD and the apparent Km values were 3.4 +/- 0.2 (SD) microM (n = 3) for endometrium and 30.5 +/- 6.1 microM (n = 3) for adrenal cortex. In endometrium DHA was not metabolised to androstenediol in the presence of either NADH or NADPH whereas in the adrenal cortex both cofactors were utilised. However, the concentration of NADH required to achieve maximum enzyme activity was 10-fold higher (1 mM) than for NADPH (0.1 mM) and maximum activity with NADH was only 30% of that using NADPH. The apparent Km was 125 microM DHA (n = 2). The study indicates that androstenediol in endometrium does not arise from DHA metabolism but that its presence could be due to a binding protein particularly during the secretory phase. Our findings also suggest that the enzyme of endometrium differs from that of the adrenal cortex and that the kinetic properties may be related to the physiological requirements of the two tissues.     

Isolation and characterization of the testosterone-estradiol-binding globulin from human plasma. Use of a novel affinity column.

This report concerns the purification and characterization of the testosterone-estradiol-binding globulin (TeBG) from human plasma. Cohn fraction IV was submitted sequentially to ammonium sulfate preciptation, affinity chromatography, gel filtration, and isoelectric focusing. The final product was homogeneous in polyacrylamide gel electrophoresis and sodium dodecyl sulfate gel electrophoresis. Its activity was demonstrated by the finding of slightly more than one binding site/mole for dihydrotestosterone. Association constants (M-1) at 4 and 37degreesC were ascertained for three steroids: dihydrotestosterone; 2.4 x 10(9) and 0.99 x 10(9); testosterone, 1.1 x 10(9) and 0.35 x 10(9); estradiol, 0.60 x 10(9) and 0.22 x 10(9). TeBG is a glycoprotein having a molecular weight of 94000 and both the amino acid and carbohydrate content are presented along with other physical properties.     

Profiles of ligands of sex hormone binding globulin in human serum

Ligands of the sex hormone-binding globulin (SHBG) in samples of human serum were extracted into diethyl ether and the dried extracts chromatographed using Sephadex LH-20 chromatography. The resulting fractions were assayed by competitive binding to SHBG against a testosterone standard. Values for dihydrotestosterone and testosterone were similar to those obtained using radioimmunoassay. While the bulk of the material in male and non-pregnant female serum corresponded to other known ligands (5-androstane-3 alpha,17 beta-diol and 5-androstene-3 beta,17 beta-diol), the quantities of material in the androstanediol and androstenediol regions exceeded the known values for these steroids in hirsute women and in late pregnancy, suggesting the presence of other steroids as well. In addition, there was a large amount of material of low polarity present in pregnancy which was not accounted for by recognized circulating ligands. A normal pattern was found in a man with Addison's disease, suggesting that the bulk of SHBG ligands in men are derived from the testis. This was also indicated by the 60-fold higher levels of testosterone and androstenediol seen in normal testicular vein serum. High values of testosterone, androstanediol and androstenediol in a woman with untreated 21-hydroxylase deficiency suggested that large amounts of these compounds (or their precursors) can be produced by the adrenal and that their production by the adrenal is regulated at least in part by ACTH.     

Androgen metabolism in tissue recombinants composed of adult urinary bladder epithelium and urogenital sinus mesenchyme

Epithelium of the adult mouse urinary bladder (BLE) was experimentally combined with mesenchyme of the urogenital sinus (UGM) and grown in intact male hosts to produce prostate-like glandular structures. To determine the extent to which the BLE is altered in a functional sense by inductive influences from UGM, investigations into the in vitro metabolism of tritiated testosterone (T) were undertaken. An isocratic high performance liquid chromatographic (HPLC) method was developed in order to separate the metabolites of T in mouse bladder, prostate and UGM + BLE tissue recombinants. Using a C-18 reversed phase column and a tetrahydrofuran (20): methanol (40): H2O (40) mobile phase, efficient and rapid separation of T, dihydrotestosterone, 3 alpha-androstanediol, androstenedione, androstanedione and androsterone was achieved. The identities of the radiolabeled T metabolites were confirmed by recrystallization to constant specific activity. The results of the present study revealed that tissue recombinants expressed testosterone metabolic profiles only partially toward that of the adult prostate. For example, percentage formation of 5 alpha-androstanedione, 3 alpha-androstanediol and unknown polar metabolites in the UGM + BLE resembled the prostate and differed significantly from the urinary bladder. Conversely, formation of the 3 beta-androstanediol and androsterone from testosterone resembled the urinary bladder and differed from the formation of these metabolites in the prostate. These results suggest that in contrast to histomorphology, androgen-induced DNA synthesis, androgen receptor binding activity and total tissue two-dimensional gel electrophoretic protein profiles, androgen metabolic profiles in the tissue recombinants showed only partial transformation into prostatic phenotypes. Analysis of steroid-metabolic profiles, therefore, may represent an exquisite and sensitive method to assess gene expression in various hormone-responsive target tissues.     

Effects of dihydrotestosterone treatment on adrenal gland function and morphology in adult female guinea-pigs

The effect of chronic treatment of female guinea-pigs with dihydrotestosterone (DHT) on growth and function of the adrenal gland and, in particular, on the reticular zone is described. Two groups of 6 young adult, female guinea-pigs were treated with DHT (1 mg/kg dissolved in peanut oil and injected s.c.) for 30 and 60 days. Two other groups of animals, treated only with oil, were used as controls. At the end of treatment, animals were killed and adrenal glands were quickly removed. Plasma levels of pregnenolone, dehydroepiandrosterone (DHA) and its sulfate (DHA-S), 17 alpha-hydroxyprogesterone, androstenedione, testosterone, estradiol, 11-deoxycortisol, androstenedione, DHT and 3 alpha-androstanediol were determined by R.I.A. following celite microcolumn chromatography. Animals treated for 30 days showed only elevated DHT and 3 alpha-androstanediol plasma levels, whereas animals treated for 60 days also showed increased values of pregnenolone (251 +/- 62 vs 193 +/- 51 ng/dl; P less than 0.05), DHA-S (12,046 +/- 4110 vs 2780 +/- 888 ng/dl; P less than 0.001) and slightly increased values of DHA (110 +/- 31 vs 86.5 +/- 55.4). In the 30-day-treated animals no histological changes were observed, but in the 60-day-treated group the total size as well as cell volumes of the zona reticularis were significantly increased. Normal estrous cycles were observed in the 30-day-treated animals whereas the 60-day-treated animals showed a progressive acyclicity during the second month of treatment. These results indicate that in guinea-pigs, prolonged treatment with DHT induces a growth of the zona reticularis of the adrenal gland associated with increased levels of 5-ene steroids, particularly DHA-S. The mechanisms inducing these modifications are probably mediated by a DHT effect at the hypothalamic-pituitary level. A direct effect of DHT on the zona reticularis, however, cannot be excluded.     

Tissue androgens and the endocrine autonomy of breast cancer.

To evaluate whether a tumour-directed gradient in androgen levels in fatty tissue can account for the maintenance of intra-tissue oestradiol levels, androstenedione (Adione), dehydroepiandrosterone (DHEA), testosterone (Testo) and androstenediol (Adiol) were assayed in breast tumour tissues and in fatty tissue taken at different distances from the tumour. The concentration of Adione was significantly lower in tumour tissue (5.6 +/- 1.5 pmol/g tissue; mean +/- SEM; n = 14) than in the adjacent fatty tissue (20.4 +/- 2.2; P less than 0.005). Testo, by contrast, occurred in equal concentrations in tumour (0.80 +/- 0.11) and in adjacent fatty tissue (0.70 +/- 0.07). Adione levels tended to be lower after the menopause only in fatty tissue, not in the tumour tissue; for Testo no differences were observed between samples from pre- and postmenopausal patients. Tumour DHEA levels (57 +/- 12 pmol/g tissue) were lower than those in fatty tissue (117 +/- 17; P less than 0.02). As with Adione, fatty tissue DHEA concentrations tended to be higher in pre- than in postmenopausal patients. Adiol showed a similar pattern as Testo. For none of the aromatase substrates nor their precursors a tumour-directed gradient was observed. The concentration of Adione in breast cancer tissue is much lower than the reported Km of the aromatase system for Adione. We have concluded, therefore, that the maintenance of oestradiol concentrations in tumour tissues is not substrate-driven.     

Formation and turnover of long-chain fatty acid esters of 5-androstene-3 beta, 17 beta -diol in estrogen receptor positive and negative human mammary cancer cell lines in culture

Microsomal preparations derived from bovine placenta cotyledons, previously investigated as a convenient source of fatty acyl coenzyme A: estradiol-17 beta-acyl transferase, have been shown to acylate other steroids bearing 3 beta- or 17 beta-hydroxyl groups. In the presence of 0.1 mM oleoyl CoA, the apparent Km values for dehydroepiandrosterone, testosterone, and 5-androstene-3 beta,17 beta-diol (delta 5-DIOL) were 45, 67, and 20 microM, respectively. Acylation of delta 5-DIOL occurred at either the 3 beta- or 17 beta-positions to give monoesters. Testosterone, estradiol-17 beta, and delta 5-DIOL acted as competitive inhibitors for the acylation of the 3 beta-hydroxyl group of dehydroepiandrosterone (Ki values 71, 75, and 41 microM, respectively). Such data indicate that a single enzyme of wide substrate specificity may be involved in these acylation reactions. When estrogen receptor (ER) positive and negative human mammary cancer cell lines were incubated with 10 nM [3H]delta 5-DIOL, intracellular accumulation of delta 5-DIOL long-chain fatty acid esters occurred; rates being higher (p less than 0.001) in ER negative cells (MDA-MB-231 and MDA-MB-330) compared to MCF-7 cells (ER positive), and higher (P less than 0.005) in MDA-MB-231 cells compared to ZR-75-1 cells (ER positive). After exposure to 10 nM [3H]delta 5-DIOL for 16 h, the total labeled steroid fatty acid fraction was composed predominantly of delta 5-DIOL-3 beta- and 17 beta-monoesters (approximately 85%), the remainder containing approximately equal amounts of delta 5-DIOL-diesters and dehydroepiandrosterone-3 beta-esters. Subsequent transfer to medium lacking delta 5-DIOL was accompanied by a breakdown of the labeled esters, which was more rapid in the ER positive cell lines. During this period, intracellular free delta 5-DIOL levels rapidly declined in MDA-MB-330 cells but were maintained in MCF-7 cells, presumably by binding to ER. This behavior parallels that of estradiol-17 beta previously observed in these cell lines and further emphasizes the potential importance of the adrenal-derived estrogen delta 5-DIOL in consideration of a hormone-based etiology of human breast cancer.     

Androgen glucuronides, instead of testosterone, as the new markers of androgenic activity in women

Despite the long series of cohort studies performed during the last 20 years, the correlation between serum testosterone and any clinical situation believed to be under androgen control in women has remained elusive. This is likely related to the recent finding that the androgens made locally in large amounts in peripheral tissues from the precursor dehydroepiandrosterone (DHEA) act in the same cells where synthesis takes place and are not released in significant amounts in the circulation, thus making unreliable the measurement of serum testosterone as marker of total androgenic activity. The objective is to determine if serum androgen glucuronides can be replaced by testosterone or another steroid as measure of androgenic activity.

Since the glucuronide derivatives of androgens are the obligatory route of elimination of all androgens, these metabolites were measured by liquid chromatography tandem mass spectrometry under basal conditions in 377 healthy postmenopausal women aged 55–65 years as well as in 47 premenopausal women aged 30–35 years while testosterone was assayed by gas chromatography mass spectrometry. No correlation was found between the serum concentration of testosterone and that of androsterone glucuronide (ADT-G) or androstenediol glucuronide (3-diol-G), the androgen metabolites which account for the total pool of androgens.

The present data show that measurement of the total pool of androgens reflected by the serum levels of ADT-G and 3-diol-G cannot be replaced by serum testosterone or any other steroid, including DHEA or DHEA sulphate. These findings may have implications for women with androgen deficiency involving osteoporosis, obesity, type 2 diabetes, sexual dysfunction, loss of muscular strength and a series of other clinical situations affecting women's health. Measuring ADT-G and 3-diol-G might identify cases of true androgen deficiency and provide an opportunity to offer appropriate androgen therapy.     

Simultaneous radioimmunoassay of testosterone,dihydrotestosterone, 5α-androstane-3α, 17β-diol and 5α-androstane-3β, 17β-diol in the plasma of adult male rats

A single thin layer chromatography and three antibodies were used for the specific radioimmunoassay of four androgens in pooled rat plasma (Sprague-Dawley adult males). The following values were found (pg/ml ± SD). Testosterone : 3, 138 ± 173; dihydrotestosterone : 374 ± 20; 5α-androstane-3α 17β-diol : 284 ± 24; 5α-androstane-3β, 17β-diol : 223 ± 11.     

A role for aromatizable androgens in female rat puberty

The function that aromatizable androgens may have in female puberty is unclear. The present experiments were undertaken to examine, using a quantitative approach, the role that physiological levels of these androgens may play in determining the timing of vaginal opening and first ovulation in female rats. Serum androstenedione (delta 4) levels increased markedly between Postnatal Days 4 and 8, remained elevated through Day 16, and declined thereafter to remain at about 100 pg/ml throughout juvenile development (Days 20-32). Serum testosterone (T) also increased, though less prominently after Postnatal Day 4. Maximal values were found at Day 12 (about 150 pg/ml); thereafter, T levels decreased to intermediate values (about 100 pg/ml), which were maintained during juvenile days. Serum dehydroepiandrosterone (DHA) remained undetectable throughout prepubertal development. At puberty, serum delta 4 increased 2.5-fold, but only at the time of the preovulatory luteinizing hormone (LH) surge. In contrast, T levels increased significantly 2-fold on the early proestrous-2 phase of puberty, 3.5-fold on the morning of first proestrus, and 9-fold at the time of the LH surge. Serum DHA remained undetectable. Implantation of Silastic capsules containing T at 2 or 6 mg/ml oil into juvenile 28-day-old rats resulted in serum T levels similar to those found on early proestrous 2 (about 150-180 pg/ml) and at 1300 h of first proestrus (ca. 300-400 pg/ml), respectively. Both treatments induced precocious vaginal opening, but failed to advance first ovulation. About 50% of the T-implanted rats had ambiguous estrous-type vaginal cytology preceding the day of first diestrus, and failed to show corpora lutea at this time.(ABSTRACT TRUNCATED AT 250 WORDS)