Epitestosterone--an endogenous antiandrogen?

5α-reduction of epitestosterone is catalysed by human SRD5A1 and SRD5A2 and increases androgen receptor transactivation

Epitestosterone is a stereoisomer of the active androgen testosterone and its circulating concentrations are similar to those of testosterone in women and children. However, its biological function and pathways of metabolism remain unknown. The structural similarity to testosterone suggests a potential function in the modulation of androgen receptor signalling. It is well established that the conversion of testosterone to 5α-dihydrotestosterone enhances local androgen receptor signalling. In this study, we show that epitestosterone is metabolized to 5α-dihydroepitestosterone by both human steroid 5α-reductase isoforms, SRD5A1 and SRD5A2. Using two different variations of a reporter assay for transactivation of the human androgen receptor, we show that epitestosterone is a partial AR agonist and that the 5α-reduction of epitestosterone increases its androgenic activity. In line with this, we show that 5α-reduction of epitestosterone reduces its ability to antagonize 5α-dihydrotestosterone-induced androgen receptor transactivation. In conclusion, we provide evidence that steroid 5α-reductases regulate the modulatory effect of epitestosterone on androgen receptor signalling.

Urinary steroid profile in relation to the menstrual cycle

The interpretation of the steroidal module of the Athlete Biological Passport (ABP) in female athletes is complex due to the large variation of the endogenous urinary steroids. The menstrual cycle seems to be one of the largest confounders of the steroid profile. The duration of the different phases in the menstrual cycle differs between women and is difficult to predict only by counting days after menstruation. Here, we have determined the follicle, ovulation, and luteal phases, by assessing the menstrual hormones in serum samples collected from 17 healthy women with regular menses. Urine samples were collected three times per week during two consecutive cycles to measure the urinary steroid concentrations used in the ABP. The metabolite that was mostly affected by the menstrual phases was epitestosterone (E), where the median concentration was 133% higher in the ovulation phase compared to the follicle phase (p < 0.0001). The women with a large coefficient of variation (CV) in their first cycle also had a large CV in their second cycle and vice versa. The inter-individual difference was extensive with a range of 11%-230% difference between the lowest and the highest T/E ratio during a cycle. In conclusion, E and ratios with E as denominator are problematic biomarkers for doping in female athletes. The timing of the sample collection in the menstrual cycle will have a large influence on the steroid profile. The results of this study highlight the need to find additional biomarkers for T doping in females.

Role of non-classical effects of testosterone and epitestosterone on AMH balance and testicular development parameters

Testosterone (T) and its 17-α epimer, epitestosterone (EpiT), are described as having non-classical effects in addition to their classical androgen actions via the intracellular androgen receptor (iAR). The actions of these androgens play an essential role in triggering factors that shift Sertoli cells from the proliferation phase to the maturation phase. This process is essential for successful spermatogenesis and normal fertility. The aim of this work was to investigate the difference between T and EpiT effects in normal and in chemically castrated Wistar rats. We also tested the effects of these hormones when the iAR-dependent pathways were inhibited by the antiandrogen flutamide. Rats were chemically castrated on postnatal day (pnd) 5 using EDS, a cytotoxic agent that promotes apoptosis of Leydig cells, reducing androgen levels. Then, animals received replacement with T or EpiT and were treated or not with flutamide from pnd 6 to pnd 13 or 20 and were euthanized on pnd 14 and 21. Animals treated with EpiT and flutamide had lower body weight overall. Epididymis weight was also reduced in animals treated with EpiT and flutamide. Flutamide per se reduced epididymis weight at both ages (pnd 14 and 21). Testicular weight and the testicular/body weight ratio were reduced in EDS animals, and flutamide further reduced this weight in animals which received T replacement. EDS administration reduced mRNA levels of both AMH (anti-Müllerian hormone) and its receptor, AMHR2, at pnd 14. In the testes of flutamide-treated animals, EpiT reduced AMH, and both T and EpiT replacement diminished AMHR2 mRNA expression also on pnd 14. EDS decreased iAR expression, and androgen replacement did not change this effect on pnd 21. In rats receiving flutamide, only those also receiving T and EpiT replacement exhibited decreased iAR expression. An increase in connexin 43 expression was observed in animals treated with EpiT without flutamide, whereas in rats treated with flutamide, both hormones were ineffective to increase connexin 43 expression reduced by EDS. Our results suggest that EpiT has an antiandrogen effect on androgen-sensitive tissues such as the epididymis. Nonetheless, the effects of T and EpiT on testicular development parameters are similar. Both hormones may act through their iAR-independent non-classical pathway, regulating AMH and AMHR2, as well as iAR expression.

Impact of hormonal contraceptives on urinary steroid profile in relation to serum hormone changes and CYP17A1 polymorphism

To detect doping with endogenous steroids, six urinary steroids are longitudinally monitored in the athlete biological passport (ABP). These steroids include testosterone, etiocholanolone, androsterone, 5α-androstane-3α,17β-diol, 5β-androstane-3α,17β-diol, and the testosterone isomer epitestosterone. It is known that the intake of hormonal contraceptives may interfere with the ABP biomarkers. A previous study showed that athletes using hormonal contraceptives (HCs) display lower urinary epitestosterone concentrations than non-using athletes. In this study, we analyzed the urinary steroid profile prior to and three months after administration of an oral HC including levonorgestrel and ethinylestradiol (n = 55). The urinary concentrations of all the ABP metabolites decreased after three months, with epitestosterone showing the largest decline (median 6.78 to 3.04 ng/mL, p˂0.0001) followed by 5α-androstane-3α,17β-diol (median 23.5 to 12.83 ng/mL, p˂0.0001), and testosterone (median 5.32 to 3.66, p˂0.0001). Epitestosterone is included in two of the five ratios in the ABP (T/E and 5αAdiol/E), and consequently these ratios increased 1.7-fold (range 0.27 to 8.50) and 1.26-fold (range 0.14 to 5.91), respectively. Some of these changes may mimic the changes seen after administration of endogenous steroids leading to atypical findings. Notably, even though participants used the same contraceptive treatment schedule, the HC-mediated epitestosterone change varied to a large extent (median 0.43-fold, range 0.06 to 6.5) and were associated with a functional T˃C promoter polymorphism in CYP17A1. Moreover, the epitestosterone changes correlated with HC-induced testosterone and gonadotropins changes in serum, indicating that urinary epitestosterone reflects the androgen load in HC-using women.

Simultaneous determination of androgens and prostaglandins in human urine using ultra-high-performance liquid chromatography-tandem mass spectrometry

A simultaneous quantitative profiling method for androgens and prostaglandins using ultra-high-performance liquid chromatography-tandem mass spectrometry was developed and validated to evaluate urinary androgen and prostaglandin levels. Solid-phase extraction and liquid-liquid extraction steps were combined during the sample preparation. β-Glucuronidase/arylsulfatase was also used in the enzyme hydrolysis step. Chemical derivatization was performed using 2-hydrazinopyridine for simultaneous determination of androgen and prostaglandin in the same ionization mode. The analytes were all separated and measured using multiple reaction monitoring in the positive ion mode within a run time of 22 min. The method was validated, achieving overall recoveries ranging from 81.0 to 102.9% with limits of quantification ranging from 0.01 to 2 ng/mL. The intra-day accuracy and precision ranged from 6.5 to 14.3% and from 77.1 to 106.8%, respectively. The inter-day accuracy and precision ranged from 8.9 to 18.2% and 89.9 to 101.4%, respectively. The linearity was expressed using the correlation coefficient, which was >0.99. The method developed herein was used to investigate the effects of a one-year finasteride treatment through differences in urinary androgen and prostaglandin levels between treated male pattern baldness patients and normal controls. The urinary androgen and prostaglandin levels were not significantly different between the two groups because of the administration of finasteride. The results confirmed that finasteride affects androgens and PGs related to hair regrowth and growth length, and a one-year finasteride treatment is effective for MPB. The mass spectrometry-based quantitative profiling method used herein for the investigation of male pattern baldness also holds great potential for the evaluation of androgens and prostaglandins associated with the metabolism of various inflammatory diseases.

Epitestosterone- and testosterone-replacement in immature castrated rats changes main testicular developmental characteristics

Epitestosterone is the 17α-epimer of testosterone and has been described as an anti-androgen, since it inhibits the effects produced by testosterone and dihydrotestosterone via the nuclear androgen receptor (nAR). However, epitestosterone also displays an effect which is similar to the non-classical effect of testosterone, depolarizing the membrane potential of Sertoli cells and inducing a rapid Ca²⁺ uptake. This study aimed to investigate the effects of a treatment with epitestosterone on developmental parameters of immature rats. Animals were chemically castrated by using the gonadotropin-releasing hormone (GnRH) antagonist cetrorelix and then received a replacement of 7 days with epitestosterone or testosterone. Replacement with either epitestosterone or testosterone restored the anogenital distance (AGD) and testicular weight which had been reduced by chemical castration. The immunocontent of nAR and the nAR-immunoreactivity were reduced by epitestosterone treatment in the testis of both castrated and non-castrated animals. Furthermore, testosterone was unable of changing the membrane potential of Sertoli cells through its non-classical action in the group of animals castrated and replaced with epitestosterone. In conclusion, in relation to the level of protein expression of nAR epitestosterone acts as an anti-androgen. However, it acts in the same way as testosterone when genital development parameters are evaluated. Moreover, in castrated rats epitestosterone suppressed the non-classical response of testosterone, changing the pattern of testosterone signalling via a membrane mechanism in Sertoli cells.

Liquid Chromatography-Mass Spectrometry-Based In Vitro Metabolic Profiling Reveals Altered Enzyme Expressions in Eicosanoid Metabolism

Background

Eicosanoids are metabolites of arachidonic acid that are rapidly biosynthesized and degraded during inflammation, and their metabolic changes reveal altered enzyme expression following drug treatment. We developed an eicosanoid profiling method and evaluated their changes on drug treatment.

Methods

Simultaneous quantitative profiling of 32 eicosanoids in liver S9 fractions obtained from rabbits with carrageenan-induced inflammation was performed and validated by liquid chromatography-mass spectrometry coupled to anion-exchange solid-phase purification.

Results

The limit of quantification for the devised method ranged from 0.5 to 20.0 ng/mg protein, and calibration linearity was achieved (R²>0.99). The precision (% CV) and accuracy (% bias) ranged from 4.7 to 10.3% and 88.4 to 110.9%, respectively, and overall recoveries ranged from 58.0 to 105.3%. Our method was then applied and showed that epitestosterone treatment reduced the levels of all eicosanoids that were generated by cyclooxygenases and lipoxygenases.

Conclusions

Quantitative eicosanoid profiling combined with in vitro metabolic assays may be useful for evaluating metabolic changes affected by drugs during eicosanoid metabolism.

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.

Genetic aspects of epitestosterone formation and androgen disposition: influence of polymorphisms in CYP17 and UGT2B enzymes

OBJECTIVE

Testosterone is a commonly abused androgen in sports and in the gym culture of the society. Its abuse is conventionally disclosed by urinary assay of the testosterone/epitestosterone (T/E) glucuronide ratio, which should not exceed 4. A noteworthy number of athletes, however, have higher natural ratios than 4, most likely because of decreased excretion of epitestosterone glucuronide. Falsely positive doping test results are of great concern for the legal rights of the sportsman. Our objective was to study the genetic aspects of epitestosterone formation, and to elucidate the impact of genetic variation in androgen-metabolizing enzymes.

METHODS

Urine from different study populations was analysed for androgen glucuronides by gas chromatography-mass spectrometry. All men were genotyped for the uridine diphospho-glucuronosyltransferase (UGT) 2B17 deletion polymorphism and single nucleotide polymorphisms in the cytochrome P-450c17alpha (CYP17), UGT2B15 and UGT2B7 genes. Expression of UGT2B15 mRNA in human liver samples was analysed using real-time PCR.

RESULTS

A T>C (A1>A2) promoter polymorphism in the CYP17 gene was associated with the urinary glucuronide levels of epitestosterone and its putative precursor androstene-3beta, 17alpha-diol, resulting in 64% higher T/E ratios in A1/A1 homozygotes. Individuals devoid of UGT2B17 had significantly higher UGT2B15 mRNA levels in liver than individuals carrying two functional UGT2B17 alleles.

CONCLUSION

The CYP17 promoter polymorphism may partly explain high natural (>4) T/E ratios. Our data indicate that 5-androstene-3beta, 17alpha-diol is an important precursor of epitestosterone and that CYP17 is involved in its production. In addition, we found that lack of the UGT2B17 enzyme may be compensated for by increase in UGT2B15 transcription.

Tissue and serum levels of principal androgens in benign prostatic hyperplasia and prostate cancer

Androgens are considered to play a substantial role in pathogenesis of both benign prostatic hyperplasia (BPH) and prostate cancer. The importance of determination of androgen levels in tissue and serum for cancer progression and prognosis has been poorly understood. The aim of study was to find out hormonal differences in both diseases, their correlations between intraprostatic and serum levels and predicted value of their investigation. Testosterone, dihydrotestosterone, androstenedione and also epitestosterone were determined in prostate tissue from 57 patients who underwent transvesical prostatectomy for BPH and 121 patients after radical prostatectomy for prostate cancer. In 75 subjects with cancer and 51 with BPH the serum samples were analyzed for testosterone, dihydrotestosterone and SHBG. Significantly higher intraprostatic androgen concentrations, i.e. 8.85+/-6.77 versus 6.44+/-6.43 pmol/g, p<0.01 for dihydrotestosterone, and 4.61+/-7.02 versus 3.44+/-4.53 pmol/g, p<0.05 for testosterone, respectively, were found in patients with prostate cancer than in BPH. Higher levels in cancer tissue were found also for epitestosterone. However, no differences were found in serum levels. Highly significant correlations occurred between all pairs of intraprostatic androgens and also epitestosterone as well as between serum testosterone and dihydrotestosterone (p<0.001) in both BPH and cancer groups. Correlation was not found between corresponding tissue and serum testosterone and dihydrotestosterone, either in benign or cancer samples. The results point to importance of intraprostatic hormone levels for evaluation of androgen status of patients, contrasting to a low value of serum hormone measurement.

Quantification of testosterone and epitestosterone in human urine samples by stir bar sorptive extraction – thermal desorption – gas chromatography/mass spectrometry: Application to HIV-positive urine samples

A simple method is described for the measurement of testosterone (T) and epitestosterone (ET) in human urine samples. The deconjugated steroids were extracted directly from the samples by stir bar sorptive extraction (SBSE) and derivatized in situ on the stir bar by headspace acylation prior to thermal desorption and GC/MS. Extraction and derivatization parameters, namely salt addition, temperature, and time, were optimized to improve the recovery of T and ET by SBSE. The limits of quantification (S/N 10) were 0.9 ng/mL for T and 2.8 ng/mL for ET. Quantification of the steroids in urine samples was performed using standard addition to avoid the influence of matrix effects. The method was applied for the measurement of urinary T and ET in a group of healthy volunteers and HIV+ patients. Decreased levels of T were detected in the HIV+ group, whereas the excretion of ET was comparable for the two groups. Further clinical research is required to elucidate the biomarker significance of the T/ET ratio in HIV infection.

Evidence that 17alpha-estradiol is biologically active in the uterine tissue: antiuterotonic and antiuterotrophic action

BACKGROUND

17alpha-Estradiol has been considered as the hormonally inactive isomer of 17beta-estradiol. Recently, nongenomic (smooth muscle relaxation) and genomic (light estrogenic activity) effects of 17alpha-estradiol have been reported, but no reports have yet determined its possible antiestrogenic activity. Therefore, this study investigated: the nongenomic action of 17alpha-estradiol on uterine contractile activity and its potential agonist-antagonist activity on uterine growth.

METHODS

Uterine rings from rats were isometrically recorded. Different concentrations (0.2-200 microM) of 17alpha-estradiol were tested on spontaneous contraction and equimolarly compared with 17beta-estradiol. To examine the mechanism of 17alpha-estradiol action, its effect was studied in presence of beta2-antagonist (propranolol), antiestrogens (tamoxifen and ICI 182,780) or inhibitors of protein synthesis (cycloheximide) and transcription (actinomycin D). Moreover, contractions induced by high potassium (KCl) solution or calcium in depolarized tissues by KCl-calcium free solution were exposed to 17alpha-estradiol. Collaterally, we performed an uterotrophic assay in adult ovariectomized rats measuring the uterine wet weight. The administration for three days of 0.3 microM/day/Kg 17beta-estradiol was equimolarly compared with the response produced by 17alpha-estradiol. Antiuterotrophic activity was assayed by administration of 0.3 microM/day/Kg 17beta-estradiol and various doses ratios (1:1, 1:3, 1:5, and 1:100) of 17alpha-estradiol.

RESULTS

The estradiol isomers elicited an immediate relaxation, concentration-dependent and reversible on spontaneous contraction. 17alpha-Estradiol presented lower potency than 17beta-estradiol although it did not antagonize 17beta-estradiol-induced relaxation. Relaxation to 17alpha-estradiol was not inhibited by propranolol, tamoxifen, ICI 182,780, cycloheximide or actinomycin D. The KCl contractions were also sensitive to 17alpha-estradiol-induced relaxation and calcium contractions in depolarized tissues were markedly prevented by 17alpha-estradiol, implying a reduction of extracellular calcium influx through voltage-operated calcium channels (VOCCs). Uterotrophic assay detected significant increase in uterine weight using 17alpha-estradiol, which was significantly minor as compared with 17beta-estradiol. 17alpha-Estradiol, at all doses ratios, significantly antagonized the hypertrophic response of 17beta-estradiol.

CONCLUSION

17alpha-Estradiol induces a relaxing effect, which may be independent of the classical estrogen receptor, nongenomic action, apparently mediated by inactivation of VOCCs. 17alpha-Estradiol is also a weak estrogen agonist (uterotrophic response); likewise, 17alpha-estradiol may act as an antiestrogen (antiuterotrophic response). The overall data document a nongenomic relaxing action and a novel antiestrogenic action of 17alpha-estradiol, which are relevant in estrogen-mediated uterine physiology.

Comparative studies on level of androgens in hair and plasma with premature male-pattern baldness

BACKGROUND

It is well known that male-pattern baldness (MPB) is not started from occipital, but frontal or scalp of head. We can assume that distribution of androgenic steroids is different for each region of the head.

OBJECTIVE

We hypothesize that the levels of androgenic steroids are different not only between vertex hair with MPB and controls but also between occipital hair with MPB and controls. Moreover, we want to search for the biochemical indicator in plasma and hair sample (baldness: 22, non-baldness: 13) obtained from dermatology of medical center. After then, we desire to present fundamental data regarding diagnosis, medical cure, and prevention for premature MPB.

METHODS

After hair and plasma were hydrolyzed, and then extracted with organic solvent. To assess androgenic steroids levels, we used gas chromatography-mass spectrometry (GC-MS) system in selected ion monitoring mode.

RESULTS

The level of dihydrotestosterone (DHT) and the ratio of testosterone to epitestosterone (T/E ratio) in vertex hair from premature baldness subjects were higher than in the sample of non-baldness subjects (P<0.001, 0.001), whereas the levels of androgens in occipital hair from the same baldness group were not different. In addition, we discovered the levels of DHT, testosterone, and DHT/T ratio in plasma from premature MPB were higher than in those of control subjects (P<0.001, 0.001, 0.005).

CONCLUSION

We verified that the distribution of androgenic steroids is unlike in various regions of individual subjects. Moreover, the increased DHT/T ratio in balding plasma indirectly confirms the high activity of 5alpha-reductase type II.

Epitestosterone

Epitestosterone has been identified as a natural component of biological fluids of several mammals including man. For a long time it was believed that it is a metabolite without any hormonal activity and without any marked relationship to the hormonal state in health and disease. Neither the biosynthetic pathway nor the site of its formation in man have been unequivocally confirmed to date. It apparently parallels the formation of testosterone (T), but on the other hand its concentration is not influenced by exogenous administration of testosterone. This fact creates the basis of the present doping control of testosterone abuse. In 1989 an observation was presented in a dermatological study that epitestosterone exerts an effect counteracting the action of testosterone on flank organ of Syrian hamster. Further studies showed that a complex action consisting of competitive binding of epitestosterone to androgen receptor, of inhibition of testosterone biosynthesis and its reduction to dihydrotestosterone and of antigonadotropic activity could be demonstrated in rat, mice and human tissues. It can be presumed that epitestosterone as a natural hormone can contribute to the regulation of such androgen dependent events as, e.g. the control of prostate growth or body hair distribution.

Sex- and age-related changes in epitestosterone in relation to pregnenolone sulfate and testosterone in normal subjects

Epitestosterone has been demonstrated to act at various levels as a weak antiandrogen. So far, its serum levels have been followed up only in males. Epitestosterone and its major circulating precursor pregnenolone sulfate and T were measured in serum from 211 healthy women and 386 men to find out whether serum concentrations of epitestosterone are sufficient to exert its antiandrogenic actions. In women, epitestosterone exhibited a maximum around 20 yr of age, followed by a continuous decline up to menopause and by a further increase in the postmenopause. In men, maximum epitestosterone levels were detected at around 35 yr of age, followed by a continuous decrease. Pregnenolone sulfate levels in women reached their maximum at about age 32 yr and then declined continuously, and in males the maximum was reached about 5 yr earlier and then remained nearly constant. Epitestosterone correlated with pregnenolone sulfate only in males. In both sexes a sharp decrease of the epitestosterone/T ratio around puberty occurred. In conclusion, concentrations of epitestosterone and pregnenolone sulfate are age dependent and, at least in prepubertal boys and girls, epitestosterone reaches or even exceeds the concentrations of T, thus supporting its role as an endogenous antiandrogen. The dissimilarities in the course of epitestosterone levels through the lifespan of men and women and its relation to pregnenolone sulfate concentrations raise the question of the contribution of the adrenals and gonads to the production of both steroids and even to the uniformity of the mechanism of epitestosterone formation.

Testosterone-mediated neuroprotection through the androgen receptor in human primary neurons

Estrogen is an active neuroprotectant and is presently investigated as a potential therapy against Alzheimer's disease for women. To determine if male hormones could also be neuroprotective, we investigated the effect of testosterone, methyltestosterone, and epitestosterone at physiological concentrations on primary cultures of human neurons induced to undergo apoptosis by serum deprivation. Serum deprivation significantly induces neuronal apoptosis in a protracted fashion. As expected, physiological concentrations of 17-beta-estradiol and transcriptionally inactive 17-alpha-estradiol protect neurons against apoptosis. Similar to 17-beta-estradiol, physiological concentrations of testosterone are also neuroprotective. Androgen receptors are present at 8 +/- 2 fmol/mg protein in the neuron cultures. The non-aromatizable androgen, mibolerone, is also neuroprotective and aromatase inhibitor, 4-androsten-4-OL-3,17-dione, does not prevent testosterone-mediated neuroprotection. In contrast, anti-androgen, flutamide, eliminates testosterone-mediated neuroprotection. Testosterone analog, methyltestosterone, showed androgen receptor-dependent neuroprotection that was delayed in time indicating that a metabolite may be the active agent. The endogenous anti-androgen, epitestosterone, also showed a slight neuroprotective effect but not through the androgen receptor. These results indicate that androgens induce neuroprotection directly through the androgen receptor. These data suggest that androgens may also be of therapeutic value against Alzheimer's disease in aging males.

Allopregnanolone, pregnenolone sulfate, and epitestosterone in breast cyst fluid

The risk of breast cancer is 2 to 5 times higher in patients suffering from gross cystic disease. Breast cysts are categorized into two groups (type I and type II) according to the concentration of electrolytes in the cyst fluid. The two types also differ with respect to accumulation of steroids and steroidogenic enzyme activity. In type I cysts a higher risk of breast carcinoma could be expected. Here, we studied a possible relationship between the type of cyst and levels of epitestosterone (an endogenous antiandrogen), allopregnanolone (a product of 5alpha-reductase activity), and pregnenolone-sulfate (an activator of N-methyl-D-asparate receptors). We have found five times higher levels of epitestosterone in BCF in comparison with the circulation. Allopregnanolone levels were similar to those in plasma of women in the luteal phase of the menstrual cycle. Pregnenolone-sulfate levels in BCF were about two orders of magnitude higher when compared with the circulation. No differences were found in concentrations of the steroids studied between the types of cysts.

Biochemical roles of testosterone and epitestosterone to 5 alpha-reductase as indicators of male-pattern baldness

In establishing a theory to predict male-pattern baldness, we investigated the correlation of testosterone, epitestosterone, and dihydrotestosterone with 5alpha-reductase in hair using gas chromatography-mass spectrometry. One hundred milligram hair samples were obtained from a group of balding subjects and their sons, as well as from a corresponding aged-matched, nonbalding group. The ratio of testosterone to epitestosterone was significantly greater (mean 46.41, p < 0.001; mean 35.83, p < 0.001, respectively) in the hair of balding fathers (n = 19, age 28-50 y) and their sons (n = 16, age 8-16 y) than in the hair of the nonbalding control subjects (mean 9.17 and 10.47, respectively). These findings demonstrate that analysis of terminal hair may not only provide a basis for predicting baldness when the subject is still young, but also for preventing and treating male-pattern baldness by controlling the steroid hormone balance.

Effect of antiandrogens casodex and epitestosterone on bone composition in mice

Nonsteroidal antiandrogen casodex and steroidal antiandrogen epitestosterone were administered to intact male mice, and their effect on femoral bones and circulating calcium, phosphate, testosterone, and LH were compared with controls and castrated animals. Pure antiandrogen casodex in a dose used in humans for treatment of prostate cancer decreased the weight of seminal vesicles, organ which is highly sensitive to the androgenic effect, increased insignificantly the concentration of LH and of testosterone, but did not have any effect on bone density or mineral content of bone. Epitestosterone, which not only inhibits the binding of androgens to their receptors but also inhibits the formation of dihydrotestosterone from testosterone, and is reported to interfere with aromatization of testosterone to estrogens, decreased the bone density, ash weight, and calcium and phosphate content of femoral bone tissue significantly, although not to values as low as those seen in castrated animals.

Concentration of the endogenous antiandrogen epitestosterone and androgenic C19-steroids in hyperplastic prostatic tissue

Epitestosterone (epiT, 17 alpha-hydroxy-4-androsten-3-one), an endogenous C19-steroid in humans, was considered for a long time as a physiologically inactive steroid. Recently, its antiandrogenic properties have been discovered. For the evaluation of its biological availability in the target organs the tissue concentration is of importance. EpiT, testosterone, dihydrotestosterone, and androstenedione concentrations in prostatic tissue were determined in 15 prostate samples obtained by suprapubic prostatectomy for benign prostatic hyperplasia. The steroids were extracted and separated by high-pressure liquid chromatography and determined by specific radioimmunoassay (RIA) methods. The concentration of epiT (mean 58.4 +/- 40.4 SD, range 14.0-144.0 fmol/mg protein) exceeded that of testosterone and was approximately as high as that of dihydrotestosterone. EpiT level increased with age and the correlation was significant (P < 0.05). It did not correlate significantly with testosterone but did with androstenedione and dihydrotestosterone (P < 0.05, each). As expected, a positive correlation was found between testosterone and dihydrotestosterone levels.

Plasma levels of epitestosterone from prepuberty to adult life

Epitestosterone has for a long time been considered as a biologically inactive steroid. However, recently a distinct antiandrogenic activity of this naturally occurring endogenous epimer of testosterone has been demonstrated. Epitestosterone plays a role in the control of doping with testosterone, since an arbitrary ratio of testosterone to epitestosterone in urine has been accepted as a marker for testosterone abuse. For this reason, its urinary excretion has been examined intensively by several authors. On the other hand, its concentration in the blood of men was reported only randomly in a few cases. In the present study the epitestosterone level in human plasma was determined by a specific radioimmunoassay and the concentration of epitestosterone was established in age groups of males of 6 to 65 years of age. There is a clear age dependence of epitestosterone plasma concentration in males. In young boys before puberty, antiandrogenic epitestosterone prevails over testosterone, in adults a striking decline of the ratio epitestosterone:testosterone can be observed.

Some reactions of 16 alpha,17 alpha-oxido-5 alpha-cholestane derivatives, synthesis of 17 alpha-hydroxycholest-4-en-3-one

Careful epoxidation of the delta 16-olefins 3 and 4 yielded 16 alpha,17 alpha-epoxides 5 and 6 which were reduced by lithium aluminium hydride, oxidized, and dehydrated to 17 alpha-hydroxycholest-4-en-3-one 20, i.e., an epitestosterone homolog containing a well tolerated alkyl group at position 17. Under catalysis of acids, epoxide 5 was rearranged to delta 13-16 alpha-alcohol 10. Less careful epoxidation of delta 16-olefin 4 with excess of peroxy acid led to products of double epoxidation (i.e., epoxidation, rearrangement, and another oxidation) 7 and 12. Structures of products of rearrangement were studied mainly by NMR spectroscopy.

Inhibition of steroid 17 alpha-hydroxylase and C17,20-lyase in the human testis by epitestosterone

Epitestosterone (17 alpha-hydroxy-4-androsten-3-one) inhibited competitively 17 alpha-hydroxylation of pregnenolone and subsequent C17,20-side chain cleavage of resulting 17 alpha-hydroxypregnenolone using microsomal preparations from the human testis. The inhibition constants for 17 alpha-hydroxylase and C17,20-lyase with 5-ene-precursors of C21-steroids were 96 and 12.4 mumol/l, respectively.

Determination of urinary testosterone and epitestosterone during pubertal development: a cross-sectional study in 141 normal male subjects

OBJECTIVES

Exogenous testosterone administration is classically detected by measuring the ratio of testosterone to epitestosterone in urine. Athletes are considered to be positive for drug abuse if the urinary testosterone to epitestosterone ratio is greater than 6. We aimed at investigating the urinary excretion of testosterone and epitestosterone during pubertal development.

DESIGN

We performed a cross-sectional study of 141 normal male subjects between ages 8 and 26 years.

PATIENTS

We studied 141 subjects: 32 at stage 1 of Tanner, 27 at stage 2, 30 at stage 3, 25 at stage 4 and 27 at stage 5.

MEASUREMENTS

Subjects performed a 24-hour urine collection. Urinary testosterone and epitestosterone were measured by gas chromatography-mass spectrometry with selected ion monitoring.

RESULTS

Urinary testosterone was 20.5 +/- 1.7 nmol/24 h (mean +/- SEM) at stage 1, 49 +/- 2.9 at stage 2, 98.8 +/- 3.4 at stage 3, 371.8 +/- 21.8 at stage 4 and 403.4 +/- 16.1 nmol/24h at stage 5. Urinary epitestosterone was 13.1 +/- 1.5 nmol/24h at stage 1, 29.1 +/- 3.3 at stage 2, 48.3 +/- 3.7 at stage 3, 156.3 +/- 14.8 at stage 4 and 221.1 +/- 18.6 nmol/24h at stage 5. The urinary excretions of both steroids increased significantly during puberty and were highly correlated with chronological age (P < 0.001). Comparison of the correlation slopes (P < 0.001) showed that the urinary profiles of testosterone and epitestosterone are not parallel during pubertal development. Two subjects presented a testosterone to epitestosterone ratio above 6, corresponding to a low urinary concentration of epitestosterone, without pathological explanation.

CONCLUSION

Testosterone and epitestosterone do not present the same urinary profiles throughout puberty. Marked increases of the testosterone to epitestosterone ratio can be observed at this period and may interfere with doping tests.

The effect of epitestosterone on the plasma levels of LH and FSH in ovariectomized immature rats

Immature ovariectomized female rats primed with estradiol or without estrogen priming were treated with epitestosterone i.p. After 7 h blood was collected and LH and FSH levels were determined. The dose-response relationship was a biphasic one. LH and less markedly FSH levels decreased under epitestosterone treatment with doses up to 10 mg, whereas at higher doses an increase of gonadotrophins was observed.

Secretion by the human testis of epitestosterone, with its sulfoconjugate and precursor androgen 5-androstene-3 beta,17 alpha-diol

Epitestosterone (ET) and testosterone (T), free and sulfoconjugated, as well as 5-androstene-3 beta,17 alpha-diol (5AD3 beta 17 alpha) and its 17 beta-epimer have been analyzed, by gas chromatography-mass spectrometry with stable isotope dilution, in peripheral and spermatic venous plasma of patients with left varicocele. All these androgens are secreted by the testis as evidenced by the significant concentration gradients between peripheral and spermatic venous plasma. Half of the daily ET production is ascribed to the testis, while 95% of T sulfate and roughly 70% of ET sulfate are also of testicular origin. Significant correlations between ET and 5AD3 beta 17 alpha are an indication that the 5-ene pathway is also operative for ET biosynthesis. High ratios of spermatic to peripheral venous plasma levels of ET and 5AD3 beta 17 alpha are also related to the high clearance rates of 17 alpha-hydroxy-androgens.

Epitestosterone--a potent competitive inhibitor of C21-steroid side chain cleavage in the testis

Epitestosterone (17 alpha-hydroxy-4-androsten-3-one) inhibits both 17 alpha-hydroxylation and consequent side chain cleavage of the resulting 17 alpha-hydroxyprogesterone in the rat testicular microsomes. The inhibitory activity in terms of the Ki is 2 and 1.5 times as high, respectively, as that of cyproterone acetate.

Antihormonal properties of some new A-homo-B, 19-dinor steroids of the androstane series

On solvolysis of Westphalen-type steroids with a leaving group in the position 6 beta (e.g., 2), products of elimination (followed by rearrangement and fragmentation of the steroid skeleton) were prepared (e.g., 4 and 5). These products were subsequently converted to suitable analogs of the compound, which has been reported to promote hair growth (1). Compounds 11 to 13 exhibited strong antiandrogenic activity in vivo; however, this activity could not be interpreted either in terms of inhibition of 5 alpha-reductase or by strong binding to an androgen receptor.