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Genesis (New York, N.Y. : 2000) Oct 2006A hermaphrodite fish, Kryptolebias marmoratus, is the only known vertebrate that reproduces by self-fertilization. In nature, males have been rarely observed....
A hermaphrodite fish, Kryptolebias marmoratus, is the only known vertebrate that reproduces by self-fertilization. In nature, males have been rarely observed. Low-temperature treatment during late embryonic stages is known to induce males but its efficacy is variable. Here we report that 17alpha-methyltestosterone (MT) treatment of the embryos converted most of the fish to males. We examined a time course of this male induction with histological and marker gene expression analyses. Oogenesis started in the gonads of the control embryo at hatching; spermatogenesis did not start until two months after hatching. In the MT-treated fish, oogenesis started initially as in the control but stopped completely within one month after hatching. Instead, spermatogonial proliferation started earlier than in the control fish and progressed to full spermatogenesis. Expression profiles of the sex-specific marker genes corresponded well with histological observations. From one month after hatching, expression of an oocyte-specific marker, figalpha, and a testicular somatic cell marker, dmrt1, started to increase in the control and in the MT-treated fish, respectively.
Topics: Animals; Cyprinodontiformes; Fertility; Fertilization; Fishes; In Situ Hybridization, Fluorescence; Male; Methyltestosterone; Oogenesis
PubMed: 17029221
DOI: 10.1002/dvg.20240 -
Steroids Aug 198317 alpha-Methyltestosterone and the reduced metabolites, 17 alpha-methyl-5 alpha-androstane-3 alpha, 17 beta-diol, 17 alpha-methyl-5 alpha-androstane-3 beta, 17... (Comparative Study)
Comparative Study
17 alpha-Methyltestosterone and the reduced metabolites, 17 alpha-methyl-5 alpha-androstane-3 alpha, 17 beta-diol, 17 alpha-methyl-5 alpha-androstane-3 beta, 17 beta-diol and 17 alpha-methyl-5 beta-androstane-3 alpha, 17 beta-diol, together with three hydroxylated metabolites, 17 alpha-methyl-5 beta-androstane-3 alpha, 16 alpha, 17 beta-triol, 17 alpha-methyl-5 beta-androstane-3 alpha, 16 beta, 17 beta-triol and a new metabolite, 17 alpha-methyl-5 alpha-androstane-3 beta, 6 alpha, 17 beta-triol, were isolated and identified in the urine of rabbits dosed with 17 alpha-methyltestosterone. No hydroxylated 5 alpha-metabolite of 17 alpha-methyltestosterone has been identified previously. No of 17 alpha-methyltestosterone has been identified previously. No evidence for epimerization at the C-17 position was observed.
Topics: Animals; Biotransformation; Hydroxylation; Male; Methyltestosterone; Rabbits
PubMed: 6673181
DOI: 10.1016/s0039-128x(83)90144-7 -
The American Journal of Psychiatry Jan 1974
Clinical Trial
Topics: Adult; Aggression; Clinical Trials as Topic; Depression; Dose-Response Relationship, Drug; Drug Therapy, Combination; Humans; Imipramine; Male; Methyltestosterone; Paranoid Disorders; Sex Factors; Testosterone
PubMed: 4585769
DOI: 10.1176/ajp.131.1.21 -
Food Chemistry Dec 2012A simple, rapid and sensitive method was developed for determination of 17α-methyltestosterone in aquatic products by extraction with subcritical...
A simple, rapid and sensitive method was developed for determination of 17α-methyltestosterone in aquatic products by extraction with subcritical 1,1,1,2-tetrafluoroethane (R134a) extraction and high performance liquid chromatography (HPLC). Response surface methodology (RSM) was adopted to optimise extraction pressure, temperature and co-solvent volume. The optimum extraction conditions predicted within the experimental ranges were as follows: pressure 5 MPa, temperature 31°C, and co-solvent volume 3.35ml. The analysis was carried out on XDB-C(18) column (4.6 mm × 250 mm, 5 μm) with the mobile phase acetonitrile-water (55:45, v/v), flow rate 0.8 ml/min, temperature 30°C and wavelength 245 nm. Good linearity of detection was obtained for 17α-methyltestosterone between concentrations of 50-250 ng/ml, r(2)=0.999. The method was validated using samples fortified with 17α-methyltestosterone at levels of 10, 30 and 50 ng/g, the mean recovery exceeds 90%, and the RSD values were less than 10%.
Topics: Androgens; Animals; Chromatography, High Pressure Liquid; Chromatography, Supercritical Fluid; Drug Residues; Fishes; Hydrocarbons, Fluorinated; Meat; Methyltestosterone
PubMed: 22980901
DOI: 10.1016/j.foodchem.2012.07.081 -
Fundamental & Clinical Pharmacology Aug 2016This study evaluated the effects of the isolated use of a low dose of methyltestosterone (MT) on cardiovascular reflexes and hormonal levels and its geno- and cytotoxic...
This study evaluated the effects of the isolated use of a low dose of methyltestosterone (MT) on cardiovascular reflexes and hormonal levels and its geno- and cytotoxic safety in ovariectomized rats. Female Wistar rats were divided into four groups (n = 6), respectively: SHAM (received vehicle methylcellulose 0.5%), SHAM + MT (received MT 0.05 mg/kg), OVX (received vehicle), and OVX + MT (received MT). Twenty-one days after ovariectomy, treatment was given orally daily for 28 days. The Bezold-Jarisch reflex (BJR) was analyzed by measuring the bradycardic and hypotensive responses elicited by phenylbiguanide (PBG) administration. The baroreflex sensitivity (BRS) was evaluated by phenylephrine and sodium nitroprussite. Myocyte hypertrophy was determined by morphometric analysis of H&E stained slides. Biochemical data were analyzed, as well as micronucleus assay. MT improved BRS and increased testosterone values, but did not change estradiol in the OVX group. MT did not promote changes in mean arterial pressure, heart rate, BJR, serum concentrations of troponin I, weight and histopathology of the heart. MT was able to restore the BRS in OVX rats. The geno- and cytotoxic safety of the MT was demonstrated by the absence of an increase in the micronucleus (PCEMN) or change in the ratio between normochromatic erythrocytes and polychromatic erythrocytes (NCE/PCE).
Topics: Animals; Baroreflex; Cytotoxicity Tests, Immunologic; Dose-Response Relationship, Drug; Female; Methyltestosterone; Mutagenicity Tests; Ovariectomy; Rats; Rats, Wistar
PubMed: 27148800
DOI: 10.1111/fcp.12203 -
Effects of 17α-methyltestosterone on the reproduction of the freshwater snail Biomphalaria glabrata.Genetics and Molecular Research : GMR Jan 201417-α-methyltestosterone (MT) is a synthetic hormone used in fish hatcheries to induce male monosex. Snails hold promise as possible test models to assess chemicals...
17-α-methyltestosterone (MT) is a synthetic hormone used in fish hatcheries to induce male monosex. Snails hold promise as possible test models to assess chemicals acting on the endocrine system. Biomphalaria glabrata is an aquatic gastropod mollusk (Pulmonata, Planorbidae) that can be easily maintained in aquaria, predisposing the species for use in ecotoxicological testing. This study evaluated the reproductive effects of MT on B. glabrata by examining histological changes and its reproductive performance. Ten snails per group were exposed for 4 weeks to different concentrations of MT (0.01, 0.1, and 1.0 mg/L). The total number of laid eggs, egg mass per group, size of type V oocytes, and production of spermatozoids were determined. Reproduction of B. glabrata was affected by MT. At the lowest concentration (0.01 mg/L), MT caused a statistically significant increase in the number of egg mass per snail compared with controls unexposed to MT. Histopathology analyses showed an increase in the sperm production at the higher MT concentrations of 0.1 and 1.0 mg/L. Chromatographic analyses of water samples showed that MT concentrations rapidly declined within a 96-h period. These results highlight the importance of giving more support to regulatory authorities, since MT is not registered for use on fish hatcheries in many countries around the world. Wastewater from fish farms discharged into aquatic ecosystems should be monitored for MT residues, since its presence could compromise the reproduction of other native snail species.
Topics: Animals; Female; Male; Methyltestosterone; Oocytes; Reproduction; Sex Determination Processes; Snails; Spermatozoa
PubMed: 24615026
DOI: 10.4238/2014.January.28.6 -
Drug Testing and Analysis Aug 2023The frequent detection of anabolic androgenic steroids (AAS) indicates their popularity among rule-breaking athletes. The so called long-term metabolites play a crucial... (Comparative Study)
Comparative Study
Detection time comparison of non-hydrolysed sulphated metabolites of metenolone, mesterolone and 17α-methyltestosterone analysed by four different mass spectrometric techniques.
The frequent detection of anabolic androgenic steroids (AAS) indicates their popularity among rule-breaking athletes. The so called long-term metabolites play a crucial role in their detection, and non-hydrolysed sulphated metabolites have gained renewed interest, as research has demonstrated their extended detection time compared to the more conventional markers (e.g., for metenolone and mesterolone). Their potential has been investigated using liquid and gas chromatography-mass spectrometry (LC- and GC-MS). However, due to their complementary nature, chances are that the most promising metabolite on one technique does not necessarily exhibit the same behaviour on the other and vice versa. Therefore, a comparison was carried out where as a trial model, metenolone, mesterolone and 17α-methyltestosterone were selected and the most likely long-term sulphated metabolites identified on four mass spectrometric instruments. Additionally, using a modified sample preparation procedure, comparison between conventional and non-hydrolysed sulphated metabolites between different GC-MS instruments was also included. When focusing on each individual marker, no cases were observed where a single metabolite provided a superior detection time on all instruments. Furthermore, for each AAS, there were incidences where a metabolite provided the best detection time on one instrument but could only be detected for a shorter period or not at all on other instruments. This demonstrates that metabolite detection windows and hence their added-value as target substance are unique and dependent on the analytical technique and not only on their pharmacokinetic behaviour. Consequently, in each case, a metabolite versus instrument evaluation is needed to maximise the probabilities of detecting doping offences.
Topics: Humans; Anabolic Agents; Anabolic Androgenic Steroids; Doping in Sports; Gas Chromatography-Mass Spectrometry; Mesterolone; Methenolone; Methyltestosterone; Substance Abuse Detection; Sulfates; Tandem Mass Spectrometry
PubMed: 37055939
DOI: 10.1002/dta.3481 -
The Journal of Biological Chemistry Oct 1950
Topics: Androgens; Humans; Liver; Methyltestosterone; Testosterone
PubMed: 14794680
DOI: No ID Found -
Journal of Women's Health &... Sep 2001To observe the effects of androgen replacement on neuropsychological measures in menopausal women, healthy menopausal women already using replacement estrogen were... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
To observe the effects of androgen replacement on neuropsychological measures in menopausal women, healthy menopausal women already using replacement estrogen were studied in a randomized, double-blind, active placebo-controlled, crossover comparison between two 8-week periods of treatment with (1) 0.625 mg oral esterified estrogen (E) alone and (2) in combination with 1.25 mg oral methyltestosterone (meT). After an initial baseline session, data were gathered at the end of two treatment periods. Scores on standardized psychological tests and computerized reaction times were compared between treatments, as was an overall outcome score that combined all measures. Added meT significantly improved scores on a test of complex information processing, the Switching Attention Test, but not on other tests. Mean outcome score showed no net change and wide variation. Fourteen subjects had outcome scores >1 SD from the mean, and 21 had no change. In the estrogen alone condition, three measures predicted favorable outcome with added meT: surgically compromised ovarian function, fewer physical symptoms, and higher score on a self-image measure of creativity. Added meT treatment may improve complex information processing. Despite wide disparities in outcome, an increased chance of overall improvement may be predicted by specific pretreatment measures.
Topics: Administration, Oral; Adult; Aged; Cross-Over Studies; Depression; Double-Blind Method; Drug Administration Schedule; Estrogens; Female; Hormone Replacement Therapy; Humans; Menopause; Methyltestosterone; Middle Aged; Motor Activity; Surveys and Questionnaires
PubMed: 11571096
DOI: 10.1089/15246090152563542 -
Archives of Toxicology Apr 2011The routinely used analytical method for detecting the abuse of anabolic steroids only allows the detection of molecules with known analytical properties. In our... (Comparative Study)
Comparative Study
The routinely used analytical method for detecting the abuse of anabolic steroids only allows the detection of molecules with known analytical properties. In our supplementary approach to structure-independent detection, substances are identified by their biological activity. In the present study, urines excreted after oral methyltestosterone (MT) administration were analyzed by a yeast androgen screen (YAS). The aim was to trace the excretion of MT or its metabolites in human urine samples and to compare the results with those from the established analytical method. MT and its two major metabolites were tested as pure compounds in the YAS. In a second step, the ability of the YAS to detect MT and its metabolites in urine samples was analyzed. For this purpose, a human volunteer ingested of a single dose of 5 mg methyltestosterone. Urine samples were collected after different time intervals (0-307 h) and were analyzed in the YAS and in parallel by GC/MS. Whereas the YAS was able to trace MT in urine samples at least for 14 days, the detection limits of the GC/MS method allowed follow-up until day six. In conclusion, our results demonstrate that the yeast reporter gene system could detect the activity of anabolic steroids like methyltestosterone with high sensitivity even in urine. Furthermore, the YAS was able to detect MT abuse for a longer period of time than classical GC/MS. Obviously, the system responds to long-lasting metabolites yet unidentified. Therefore, the YAS can be a powerful (pre-) screening tool with the potential that to be used to identify persistent or late screening metabolites of anabolic steroids, which could be used for an enhancement of the sensitivity of GC/MS detection techniques.
Topics: Anabolic Agents; Biological Assay; Gas Chromatography-Mass Spectrometry; Genes, Reporter; Humans; Male; Methyltestosterone; Middle Aged; Saccharomyces cerevisiae; Substance Abuse Detection; Tandem Mass Spectrometry; Time Factors; Transcriptional Activation
PubMed: 20924560
DOI: 10.1007/s00204-010-0590-0