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PubMed1995

Determination of epitestosterone and testosterone in urine by high-performance liquid chromatography.

This paper describes an alternative HPLC method for the determination of testosterone and epitestosterone, which is simple, rapid, selective, sensitive and reproducible. Samples were prepared using a previous enzymatic hydrolysis with liquid-liquid extraction. The determination was carried out on a Hypersil BDS-C18 reversed-phase column with gradient elution and UV absorbance detection (240 nm). The limits of quantification (signal-to-noise ratio = 6) were 20 ng/ml for testosterone and 30 ng/ml for epitestosterone.

Chromatography, High Pressure Liquid↗
PubMed1993

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.

Animals↗
PubMed2006

Short-term stability of testosterone and epitestosterone conjugates in urine samples: quantification by liquid chromatography-linear ion trap mass spectrometry.

A simple method using liquid chromatography-linear ion trap mass spectrometry for simultaneous determination of testosterone glucuronide (TG), testosterone sulfate (TS), epitestosterone glucuronide (EG) and epitestosterone sulfate (ES) in urine samples was developed. For validation purposes, a urine containing no detectable amount of TG, TS and EG was selected and fortified with steroid conjugate standards. Quantification was performed using deuterated testosterone conjugates to correct for ion suppression/enhancement during ESI. Assay validation was performed in terms of lower limit of detection (1-3ng/mL), recovery (89-101%), intraday precision (2.0-6.8%), interday precision (3.4-9.6%) and accuracy (101-103%). Application of the method to short-term stability testing of urine samples at temperature ranging from 4 to 37 degrees C during a time-storage of a week lead to the conclusion that addition of sodium azide (10mg/mL) is required for preservation of the analytes.

Calibration↗
PubMed2001

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.

Adult↗
PubMed1997

Androstanediol and 5-androstenediol profiling for detecting exogenously administered dihydrotestosterone, epitestosterone, and dehydroepiandrosterone: potential use in gas chromatography isotope ratio mass spectrometry.

The basis of a potential method for confirming intake of four natural androgens (testosterone, epitestosterone, dihydrotestosterone, and dehydroepiandrosterone is presented. The method relies on isolating from urine a steroid fraction containing androstenediol and androstanediol metabolites of these natural steroids and analyzing their 13C content by gas chromatography, combustion, isotope ratio mass spectrometry. The steroids were recovered from urine by conjugate hydrolysis with a Helix pomatia preparation (sulfatase and beta-glucuronidase), Girard T reagent separation to obtain a nonketonic fraction, and Sephadex LH-20 chromatography for purification. Metabolites appropriate for all of the natural steroids could be separated (as diacetates) by gas chromatography on a DB-17 capillary column viz.: 5 alpha (and beta)-androstane-3 alpha,17 alpha-diol (epitestosterone as precursor); 5 alpha (and beta)-androstane-3 alpha,17 beta-diol (testosterone as precursor); 5-androstene-3 beta,17 beta-diol (dehydroepiandrosterone precursor); and 5 alpha-androstane-3 alpha,17 beta- (and 17 alpha-) diol (dihydrotestosterone precursor). Measurement of the 13C content of the specific analytes after ingestion of the androgen precursors demonstrated a lowering of delta 13C/1000 value compared to normal values. Typically, in the male individual studied, delta 13C/1000 values for all components were -26 to -27 before drug administration and -29 to -30 at 6 h after, the latter values reflecting those obtaining for commercial synthetic steroid compared to in vivo synthesized steroid. While generally the metabolism of the steroids was as expected, this was not the case for 5 alpha-dihydrotestosterone. A major metabolite was 5 alpha-androstane-3 alpha,17 alpha-diol, which had presumably been formed by 17 beta/17 alpha isomerization, a process previously known for unnatural anabolics but not for natural hormones. The isolation, purification, and isotope ratio mass spectrometry techniques described may form the basis of a general method for confirming natural steroid misuse by sports participants.

Androstane-3,17-diol↗
PubMed1997

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.

Androgen Antagonists↗
PubMed2001

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.

5-alpha Reductase Inhibitors↗
PubMed1987

Epitestosterone: a potential new antiandrogen.

Epitestosterone (EpiT) is the 17 alpha-hydroxy epimer of testosterone (T) and a natural steroid metabolite. It has previously been shown to be a 5 alpha-reductase inhibitor. We have studied EpiT as an antiandrogen using the hamster flank organ model. One-centimeter silastic capsules of crystalline T or dihydrotestosterone (DHT) were implanted subcutaneously in female Golden Syrian hamsters to provide continuous androgenic stimulation. After 3 weeks, the pigmented spot was measured and the flank organs were fixed for histologic sectioning. The maximum surface area (SA) from a central section of the sebaceous gland and the diameter of hair follicles were measured using a computerized digitizing tablet. Following T and DHT, respectively, there was a significant increase in pigmented spot size (656/382%), sebaceous gland SA (210/315%), and mean hair follicle diameter (80/56%). A 1-cm capsule of EpiT alone had no androgenic effect. Five- and ten-fold doses of EpiT were implanted with T or DHT. Epitestosterone significantly inhibited the T-dependent stimulation of pigment, sebaceous gland, and hair follicle at either 5- and/or 10-fold excess doses. Additionally, a 10-fold dose of EpiT also inhibited DHT-dependent stimulation of all 3 cutaneous structures. We conclude that EpiT was effective as an antiandrogen and had no intrinsic androgenic activity in the hamster flank organ. It probably functions both as a competitive inhibitor of the androgen receptor and as a 5 alpha-reductase inhibitor. Pigment and sebaceous gland growth were more sensitive than the hair follicle to androgen inhibition by EpiT at the time and doses tested.

Androgen Antagonists↗
PubMed1986

Testosterone and epitestosterone metabolism of single hairs in 5 patients with 5 alpha-reductase-deficiency.

5 alpha-reductase activity was investigated in scalp hair roots in 5 patients with 5 alpha-reductase deficiency and in 10 normal volunteers (5 men and 5 women) who served as controls. Metabolism of [3H]testosterone and [3H]epitestosterone was measured under standardized conditions in 1-4 growing (anagen) hair roots. When the mean values of the 5 alpha-reduced metabolites from testosterone (androstanedione and dihydrotestosterone) or from epitestosterone (epidihydrotesterone) were compared in both groups, similar values were observed. However, since most of the hair roots were incubated singly, it could be demonstrated that in two patients 20 respectively 24% of the hair roots showed neither dihydrotestosterone nor epidihydrotestestosterone formation. This did not influence the mean values determined for the whole group perceptibly. Our results support the concept that 5 alpha-reductase deficiency is a genetically heterogenous disorder by demonstrating that the enzyme defect is variously expressed in hair roots of affected individuals.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1979

[Testosterone, epitestosterone and total estrogen excretion in men with cancer of certain localizations].

To obtain more insight into the problem on the concentration of active androgens in the male organism, the diurnal elimination of testosterone, epitestosterone and estrogens in the urine of male patients with cancer of the lung, urinary bladder, larynx and prostate (321 patients), in stage II--III, was estimated. In patients with cancer of the lung and urinary bladder testosterone was found to be lowered, while total estrogens--lowered or unchanged irrespective of age, a relative hyperestrogenization being noted in them. Contrary, in cancer of the larynx and prostate the male hormones were predominating over female ones (hyperandrogenization). In all the examined patients irrespective of the tumor process localization a relative or even absolute predominance of epitestosterone over testosterone was evident.

Adult↗
PubMed1993

[Study of urinary excretion of testosterone and epitestosterone glucuronides in children and adolescents].

Urinary testosterone to epitestosterone ratio (T/E) is used as a marker for illegal exogenous testosterone use. Mean value in healthy adults is 1.13 and 6 is the upper limit of the accepted range. Urinary excretion of these two steroids were studied in 57 children and teenagers at different pubertal stages, using gas chromatography coupled with mass spectrometry with selective ion detection. Urinary excretion of testosterone and epitestosterone increased significantly during puberty. Mean T/E ratio remained fairly constant but interindividual variations were marked and in one subject the T/E ratio exceeded 6. These data suggest that this test may yield false-positive results in adolescents.

Adolescent↗
PubMed2006

Stability studies of testosterone and epitestosterone glucuronides in urine.

The stability of testosterone glucuronide (TG), epitestosterone glucuronide (EG) and the T/E ratio in urine has been studied. Samples were analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Urine samples were submitted to a solid-liquid cleanup followed by extraction of unconjugated testosterone (T) and epitestosterone (E) with tert-butyl methyl ether (free fraction). The remaining aqueous phase was hydrolyzed with beta-glucuronidase and extracted at alkaline pH with n-pentane. Analytes were analyzed by GC/MS as their enol-trimethylsilyl (TMS) derivatives. The urine for stability testing was obtained from an excretion study after the administration of T to healthy volunteers. The homogeneity of the sample was verified before starting the stability study. The stability of TG and EG was evaluated at different storage conditions. For long-term stability testing, analyte concentration in urine stored at 4 degrees C and -20 degrees C was determined at different time intervals for 22 months. For short-term stability testing, analyte concentration was evaluated in urine stored at 37 degrees C for 3 and 7 days. The effect of repeated freezing (at -20 degrees C) and thawing (at room temperature) was studied for up to three cycles. Data obtained in this work demonstrated the stability of TG, EG and the T/E ratio in sterilized urine samples stored at 4 and -20 degrees C for 22 months and after going through repeated freeze/thaw cycles. Decreases in concentration were observed after 7 days of storage at 37 degrees C due to the partial cleavage of the glucuronide conjugates; however, the T/E ratio was not affected. These results show the feasibility of preparing reference materials containing TG and EG to be used for quality control purposes.

Doping in Sports↗
PubMed1996

Urinary testosterone (T) to epitestosterone (E) ratios by GC/MS. I. Initial comparison of uncorrected T/E in six international laboratories.

Six laboratories in six countries collaborated to investigate the analytical method for estimating the testosterone to epitestosterone ratio (T/E) in urine by gas chromatography/mass spectrometry in the context of detecting the application of T as a doping agent in sport. The protocol specified many but not all details of reagents and instrument conditions. The design included the distribution and analysis of four urines with different T/E values, three replicates per value, and one standard. The ranges of mean T/E values for the four urines estimated by peak area (PA) were 0.32-0.42, 0.72-0.94, 0.91-1.14 and 3.19-5.48. The analyses of variance for these data and for the peak height (PH) data were significant for the laboratory factor (p < 0.0001). In addition there was a significant interaction between the urine factor and the laboratory factor which indicates the complexity of the analysis. T/E calculated using PA was not significantly different from that using PH. For within-laboratory precision all values for PH and PA were < 8.3%, and for between-laboratory precision all values were < 11.7% except for one (20.1%). The data represent a baseline for future experiments designed to elucidate the sources of within-and between-laboratory variance, and to harmonize estimates of T/E.

Analysis of Variance↗
PubMed1996

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.

Aged↗
PubMed1989

The in vitro biosynthesis of epitestosterone and testosterone from C19 steroid precursors in the testis of the lizard Tiliqua rugosa.

The metabolism of androgens in the testis of the lizard Tiliqua rugosa has been studied in vitro by incubating cellular homogenates with radiolabeled C19-steroid substrates. The identification 17 beta-oxidoreductase and 3 beta-hydroxysteroid dehydrogenase/isomerase activities. Aromatase, 5 alpha-reductase, and 17 alpha/beta-epimerase activities were not detected. The 17 alpha-oxidoreductase activity was temperature dependent (maximal at 32 degrees), while the 17 beta-oxidoreductase activity was temperature independent. Time yield and dual-label studies indicated that testosterone biosynthesis mainly involves the 4-ene pathway (via androstenedione), whereas the formation of epitestosterone uses both the 4-ene and 5-ene (via 5-androstene-3 beta, 17 alpha-diol) pathways. The function of alternative pathways in androgen biosynthesis is discussed, as is the role of temperature in the intratesticular regulation of androgen production.

Androstenediol↗
PubMed1993

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.

Adult↗
PubMed1993

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.

Aldehyde-Lyases↗