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Publication
Journal: Talanta
October/25/2010
Abstract
A pseudo-homogeneous immunoextraction method based on gold-coated magnetic nanoparticles (MNPs) for the specific extraction and quantitative analysis of epitestosterone (17alpha-hydroxy-4-androsten-3-one, abbreviated as "ET") from human urine samples by high-performance liquid chromatography (HPLC) has been developed. Half-IgG of anti-ET monoclonal antibodies were covalently immobilized onto (Fe(3)O(4))(core)-Au(shell) (Fe(3)O(4)@Au) MNPs. An external magnetic field was applied to collect the MNPs which were then rinsed with distilled water followed by elution with absolute methanol to obtain ET as the analyte. The obtained extraction solution was analyzed by HPLC with UV detection (244nm) within 12min. The standard calibration curve for ET showed good linearity in the range of 20-200ngmL(-1) in phosphate-buffered saline (PBS) solutions with acceptable accuracy and precision. Limit of detection for ET was 0.06ngmL(-1) due to an enrichment factor of 100-fold was achieved. The results obtained by the present method for spiked human urine samples were in agreement with those from indirect competitive enzyme-linked immunoadsorbent assays (ELISAs). The antibody-conjugated Fe(3)O(4)@Au MNPs are novel materials for immunoaffinity extraction. Compared with the conventional technique using immunoaffinity column, the method described here for sample pretreatment was fast, highly specific, and easy to operate.
Publication
Journal: Journal of Endocrinology
May/30/1985
Abstract
Administration of flumethasone (3.5 mg i.m.) to six cows on day 260 of pregnancy induced parturition in only one animal. In the other five cows circulating concentrations of epitestosterone and conjugated oestrogens increased to reach maximum values (epitestosterone, 13.73 +/- 2.81 nmol/l; conjugated oestrogens, 33.59 +/- 6.87 nmol/l) 2-3 days after treatment. Concentrations of these steroids were raised as long as the synthetic glucocorticoid was present in the circulation (as judged by depression of cortisol concentrations). After clearance of the drug, concentrations of these steroids declined to values present in the control group. Concentrations of unconjugated oestrogens were only slightly raised after flumethasone. In contrast to the effect observed after administration on day 260, treatment on day 270 induced parturition in four of six treated animals. In these cows, mean circulating concentrations of epitestosterone, unconjugated and conjugated oestrogens increased to 9.50 +/- 2.96, 9.62 +/- 1.48 and 36.51 +/- 4.8 nmol/l respectively to reach concentrations observed in the control group at parturition. After parturition the concentrations of epitestosterone and oestrogens declined rapidly in all groups.
Publication
Journal: Endocrinology
January/20/1971
Publication
Journal: Endocrinology
March/21/1970
Publication
Journal: Acta Endocrinologica
March/27/1967
Publication
Journal: Clinical Chemistry
December/13/1995
Abstract
Currently, there is no recommended confirmatory procedure for detecting doping with the anabolic steroid 5 alpha-dihydrotestosterone (DHT) in sportsmen. To develop a method, we determined ratios of hormone concentrations in urine from 120 healthy men and used these to set discrimination limits. These limits were then applied to results for urine specimens from 10 volunteers given DHT percutaneously (125 mg twice daily for 4 days). The ratio of DHT to epitestosterone (EpiT) was chosen as the primary marker of DHT administration, and ratios of 5 alpha-androstane-3 alpha, 17 beta-diol (5 alpha-ADIOL) to EpiT, 5 alpha-ADIOL to luteinizing hormone, and 5 alpha-ADIOL to 5 beta-androstane-3 alpha, 17 beta-diol were proposed as secondary markers. To evaluate method suitability, we analyzed 194 samples from sports competitors; results for 193 samples were negative, but the ratios in 1 sample greatly exceeded all the chosen limits. In conclusion, we propose that a test scheme based on our recommendations be considered for implementation in all Olympic drug-testing laboratories.
Publication
Journal: Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)
November/30/1996
Publication
Journal: European journal of biochemistry
March/30/1974
Publication
Journal: Endocrinology
January/31/1973
Publication
Journal: Biochimica et Biophysica Acta - General Subjects
February/9/1968
Publication
Journal: Journal of Steroid Biochemistry and Molecular Biology
February/2/1993
Abstract
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.
Publication
Journal: Pharmacological Reports
July/15/2013
Abstract
While a recent study has reported that early citalopram exposure alters cortical network function and produces autistic-like behaviors in male rats, when evaluating antidepressant animal models of autism spectrum disorder (ASD) it is important to note that some selective serotonin (5-HT) reuptake inhibitors alter 3α-hydroxysteroid dehydrogenase activity, and thus steroidogenesis. At least one study has examined the effect of repeated citalopram administration on the serum and brain concentration of testosterone (T) and its metabolites and shown that citalopram increases serum T. Several in vitro studies also suggest that sex steroid can alter 5-HT homeostasis. While research efforts have demonstrated that transgenic mice expressing the most common of multiple gain-of-function 5-HT reuptake transporter (SERT) coding variants, SERT Ala56, previously identified in children with ASD, exhibit autistic-like behaviors, elevated p38 MAPK-dependent transporter phosphorylation, enhanced 5-HT clearance rates and hyperserotonemia, a few studies provide some evidence that 5-HT may alter gonadal steroidogenesis. T, 17β-estradiol and synthetic estrogens are known inhibitors of AKR1C21 (BRENDA, E.C. 1.1.1.209), the epitestosterone (epiT) producing enzyme in rodents. EpiT is a naturally occurring steroid in mammals, including man. An analysis of the literature suggests that epiT may be the central mediator in the epigenetic regulation of gene expression. Over thirty years ago, it was shown that rat brain epiT production is higher in females than in males. A similar finding in humans could explain the sex differences in the incidence of autism and other brain disorders. Despite this, the role of epiT in brain development remains a long neglected area of research.
Publication
Journal: Food additives and contaminants
June/25/2006
Abstract
Conflicting findings regarding the boldenone content of bovine faeces suggest it may be synthesized de novo in emitted faeces. We tested this hypothesis by analysing uncontaminated urine, fresh and various forms of dried faeces from 10 calves (not given boldenone) by liquid chromatography/tandem mass spectrometry for 17alpha- and 17beta-boldenone (alpha and beta BOL); 1,4-androstadiene-3,17-dione (ADD); 4-androstene-3,17-dione (AED), testosterone (T) and epitestosterone (ET). Urine contained no alpha BOL, beta BOL or ADD. The analysed substances were variably present in the rectal faeces, and at generally higher levels in faeces scraped from skin or stall floor. In pooled rectal faeces naturally dried for 13 days, alpha BOL, ADD, AED and ET levels were extremely high (much higher than accounted for by increases due to drying), and beta BOL and T were absent. It is concluded that de novo synthesis of alpha BOL and metabolites occurs naturally in bovine faeces and only uncontaminated urine should be analysed for illegal boldenone.
Publication
Journal: Endokrinologie
October/6/1971
Publication
Journal: The Journal of obstetrics and gynaecology of the British Commonwealth
February/1/1970
Publication
Journal: Journal of Endocrinological Investigation
December/13/2009
Abstract
OBJECTIVE
To describe serum and urinary hormones, androgens metabolites and testosterone/epitestosterone ratio profiles after testosterone administration in male hypogonadal volunteers, and to evaluate their possible usefulness in detecting doping with testosterone in treated hypogonadal athletes.
METHODS
Controlled open label design vs placebo; pharmacokinetic study.
METHODS
Ten male volunteers affected by severe hypogonadism (serum testosterone <2.31 ng/ml).
METHODS
Serum and urinary parameters were evaluated, by radioimmunoassay and gas chromatography-mass spectrometry, before and at different time points for 7/3 weeks after a single administration of testosterone enanthate (250 mg) or placebo, respectively.
RESULTS
As partially known, testosterone administration increased, with great individual variability, urinary concentrations of glucuronide testosterone, androsterone, etiocholanolone, 5alpha-androstane- 3alpha,17beta-diol, 5beta-androstane-3alpha,17beta-diol, testosterone/ epitestosterone and testosterone/LH ratios; and decreased epitestosterone and 5alpha-androstane-3beta,17beta-diol/5beta-androstane- 3alpha,17beta-diol ratio. Serum testosterone and dihydrotestosterone increased in all volunteers, and concentrations higher than the upper reference limits were observed in many volunteers until 2 weeks after testosterone administration.
CONCLUSIONS
Whereas the observed prolonged hyperandrogenism partially limited data interpretation, the report ed characteristics of variation of urinary parameters might be used to suspect testosterone misuse in hypogonadal athletes treated with testosterone enanthate. In this sense, while the actual threshold for tes tos terone/epites tos ter one ratio was confirmed to be of reduced usefulness, we suggest a contemporary evaluation of whole urinary androgen metabolites profile and serum androgens, at specific time points after testosterone enanthate administration. Moreover, an adequate tailoring of treatment, to avoid transitory hyperandrogenism, is highly advisable. Further studies on strategies for detecting doping with testosterone in hypogonadal athletes are warranted.
Publication
Journal: Andrologia
June/10/1977
Abstract
Urinary testosterone and epitestosterone were assayed in 60 men: 7 normals and 53 patients with chronic prostatitis (of these 8 patients had prostatis free of complications, 45 had prostatitis with disturbances of generative and copulative functions). In 73.1% of patients considerable reduction of testosterone excretion was revealed. Reduction of testicular endocrine function is in direct correlative dependence on severity of clinical symptoms, duration of disease and form of chronic prostatis. Disturbances of genital hormone metabolism are of considerable importance in case of chronic prostatitis and its complications.
Publication
Journal: Drug Testing and Analysis
May/3/2012
Abstract
The suppression of steroid biotransformation resulting in a decrease of the major urinary metabolites--androsterone and etiocholanolone--and the elevation of testosterone/epitestosterone (T/E) ratios following ethanol administration is well described. At least the latter parameter T/E represents an important indicator for endogenous steroid abuse in doping control. The quantitative correlation between ethanol consumption markers and steroid profile alteration was evaluated, aiming to differentiate between permitted ethanol administration and potential steroid abuse. Steroid profiles, ethanol, ethyl glucuronide (EtG), and sulfate (EtS) were quantified after administration of ethanol (intended maximum ethanol concentration in blood was 1 mg/g) to 21 male and 15 female volunteers. EtG concentrations in urine (corrected by either specific gravity or creatinine concentration) were found to be most suitable for quantitative evaluations. Gender specific urinary EtG concentrations of 48 ug/ml (men) and 15.5 ug/ml (women) may be considered as useful thresholds for a potential ethanol-induced suppression of steroids biotransformation.
Publication
Journal: Drug Testing and Analysis
July/4/2010
Abstract
The potential influence of alcohol consumption on endogenous steroids has already been described in the literature. In those studies the ethanol level after ingestion was monitored using its concentration in blood, urine or saliva. Corresponding methods are not commonly used in anti-doping laboratories. Ethylglucuronide (EtG), which can be easily detected by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), appears to be a more suitable parameter for this purpose. It is slowly excreted into the urine and indicates alcohol intake for a much longer period than blood or urinary alcohol and it is therefore routinely used for legal purposes as an alcohol consumption marker. In pharmacokinetic studies that aimed to establish calculation models after ethanol intake, the formation of EtG was observed to coincide with elevated urinary testosterone/epitestosterone (T/E) ratios. Similarly, large amounts of EtG were correlated with abnormal steroid profiles found in routine doping samples. In this pilot study, several cases with significantly elevated T/E ratios were associated with urinary EtG concentrations higher than 50 microg/mL. These findings confirmed recent intake of ethanol in considerable amounts and suggest a connection to changes in specific steroid profile parameters. Owing to the ease with which procedures to determine EtG can be carried out, and the potential for such procedures to be introduced into screening schemes, the inclusion of this marker in the final evaluation of suspicious outliers in T/E ratio longitudinal studies would seem to be very useful.
Publication
Journal: Steroids
December/15/1985
Abstract
The inhibitory effects of different steroids and related compounds on sheep peripheral blood lymphocytes (PBL) during exposure to the mitogen, phytohemagglutinin (PHA), have been measured by the reduction of [3H]thymidine incorporation into DNA. Dose-response curves showed that a maximum (or near maximum effect) was achieved at a steroid concentration of 12.5 microM. At this dose 19 of 41 compounds significantly reduced thymidine incorporation by activated PBL (P less than 0.01 to P less than 0.001). The greatest reduction was observed with 17-hydroxyprogesterone (-59%, i.e. reduced by 59% compared with vehicle control, 100%) greater than androstenedione greater than epitestosterone greater than estradiol-3-methyl ether greater than 20 alpha-dihydroprogesterone greater than medroxyprogesterone acetate greater than 5 beta-pregnane-3,20-dione greater than 5 alpha-pregnane-3,20-dione (-24%). Among the steroids which showed the greatest inhibitory effect, 6 had a 4-en-3-one group in ring A, 4 had a saturated ring A (pregnane or androstane) and one had a 3-methyl ether group and a phenolic ring A. The wide range of structures represented by these inhibitory steroids suggests that inhibition of lymphocyte mitogenesis involves more than one mechanism.
Publication
Journal: Journal of Pharmaceutical and Biomedical Analysis
July/31/2007
Abstract
A method had been developed for determination of residues of 10 anabolic steroids (ASs) in animal muscle tissues by liquid chromatography tandem mass spectrometry (LC/MS/MS). After enzymolysis, the sample was extracted with tert-butyl methyl ether, cleaned up through reverse solid-phase extraction and further determined by LC/MS/MS under multiple reaction monitoring (MRM) mode. The limits of detection (LOD) of LC/MS/MS method used for testing epitestosterone (ETS), nandrolone (17 beta-NT), 17 alpha-methyl-testosterone (MTS), testosterone 17-propionate (PTS), medroxyprogesterone (MED), progesterone (PG), estrone (ESN), 17 beta-estradiol (17 beta-ES), 17alpha-ethynylestradiol (EES) and estriol (EST) in animal muscle ranged from 0.06 to 0.22 microg/kg, and the limits of quantification (LOQ) were from 0.12 to 0.54 microg/kg. Experiments on spiked samples of pork, beef, chicken and fish showed that at addition level of 1.0 microg/kg, the average recoveries of the ASs ranged from 64% to 77%, and coefficients of variation from 7.1% to 20.3%, while at addition level of 2.0 microg/kg, the average recoveries ranged from 70% to 89%, and coefficient of variation from 7.1% to 19.1%.
Publication
Journal: Rapid Communications in Mass Spectrometry
August/12/2009
Abstract
The development and application of a combined gas chromatography/thermal conversion/isotope ratio mass spectrometry (GC/TC/IRMS) method for D/H ratio determination of endogenous urinary steroids are presented. The key element in sample preparation was the consecutive cleanup with high-performance liquid chromatography of initially native and subsequently acetylated steroids. This strategy enabled sufficient cleanup off all target analytes for determination of their respective D/H values. Ten steroids (11beta-hydroxyandrosterone, 5alpha-androst-16-en-3alpha-ol, pregnanediol, androsterone, etiocholanolone, testosterone, epitestosterone, 5alpha-androstan-3alpha,17beta-diol, 5beta-androstan-3alpha,17beta-diol and dehydroepiandrosterone) were measured from a single urine specimen. Depending on the biological background, the determination limit for all steroids ranged from 10 to 15 ng/mL for a 20 mL specimen. The method was validated by application of linear mixing models on each steroid and covered repeatability and reproducibility. The specificity of the procedure was ensured by gas chromatography/mass spectrometry (GC/MS) analysis of the sample using equivalent chromatographic conditions to those employed in the GC/TC/IRMS measurement. Within the sample preparation, no isotopic fractionation was observed, and no amount-dependent shift of the D/H ratios during the measurement was noticed. Possible memory effects occurring during IRMS measurements were corrected by applying a simple rule of proportion. In order to determine the naturally occurring D/H ratios of all implemented steroids, a population of 18 male subjects was analyzed. Relevant mean Delta values among selected steroids were calculated which allowed us to study the metabolic pathways and production sites of all the implemented steroids with additional consideration of the corresponding (13)C/(12)C ratios.
Publication
Journal: Drug Testing and Analysis
May/4/2011
Abstract
Doping with natural steroids can be detected by evaluating the urinary concentrations and ratios of several endogenous steroids. Since these biomarkers of steroid doping are known to present large inter-individual variations, monitoring of individual steroid profiles over time allows switching from population-based towards subject-based reference ranges for improved detection. In an Athlete Biological Passport (ABP), biomarkers data are collated throughout the athlete's sporting career and individual thresholds defined adaptively. For now, this approach has been validated on a limited number of markers of steroid doping, such as the testosterone (T) over epitestosterone (E) ratio to detect T misuse in athletes. Additional markers are required for other endogenous steroids like dihydrotestosterone (DHT) and dehydroepiandrosterone (DHEA). By combining comprehensive steroid profiles composed of 24 steroid concentrations with Bayesian inference techniques for longitudinal profiling, a selection was made for the detection of DHT and DHEA misuse. The biomarkers found were rated according to relative response, parameter stability, discriminative power, and maximal detection time. This analysis revealed DHT/E, DHT/5β-androstane-3α,17β-diol and 5α-androstane-3α,17β-diol/5β-androstane-3α,17β-diol as best biomarkers for DHT administration and DHEA/E, 16α-hydroxydehydroepiandrosterone/E, 7β-hydroxydehydroepiandrosterone/E and 5β-androstane-3α,17β-diol/5α-androstane-3α,17β-diol for DHEA. The selected biomarkers were found suitable for individual referencing. A drastic overall increase in sensitivity was obtained. The use of multiple markers as formalized in an Athlete Steroidal Passport (ASP) can provide firm evidence of doping with endogenous steroids.
Publication
Journal: Analytical and Bioanalytical Chemistry
November/22/2011
Abstract
Currently a large range of pure substance reference materials are available for calibration of doping-control methods. These materials enable traceability to the International System of Units (SI) for the results generated by World Anti-Doping Agency (WADA)-accredited laboratories. Only a small number of prohibited substances have threshold limits for which quantification is highly important. For these analytes only the highest quality reference materials that are available should be used. Many prohibited substances have no threshold limits and reference materials provide essential identity confirmation. For these reference materials the correct identity is critical and the methods used to assess identity in these cases should be critically evaluated. There is still a lack of certified matrix reference materials to support many aspects of doping analysis. However, in key areas a range of urine matrix materials have been produced for substances with threshold limits, for example 19-norandrosterone and testosterone/epitestosterone (T/E) ratio. These matrix-certified reference materials (CRMs) are an excellent independent means of checking method recovery and bias and will typically be used in method validation and then regularly as quality-control checks. They can be particularly important in the analysis of samples close to threshold limits, in which measurement accuracy becomes critical. Some reference materials for isotope ratio mass spectrometry (IRMS) analysis are available and a matrix material certified for steroid delta values is currently under production. In other new areas, for example the Athlete Biological Passport, peptide hormone testing, designer steroids, and gene doping, reference material needs still need to be thoroughly assessed and prioritised.
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