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Zebrafish Dec 2022Severely skewed sex ratios in zebrafish stocks can pose significant hurdles for line propagation and sperm cryopreservation. To overcome female-biased sex ratios in... (Review)
Review
Severely skewed sex ratios in zebrafish stocks can pose significant hurdles for line propagation and sperm cryopreservation. To overcome female-biased sex ratios in stocks derived from imported sperm samples, the Zebrafish International Resource Center has implemented routine supplementation of larval food with 17α-methyltestosterone to skew gonadal sex differentiation toward masculinization. Resulting stocks averaged 80% males.
Topics: Male; Female; Animals; Zebrafish; Methyltestosterone; Semen; Gonads; Sex Differentiation
PubMed: 36318811
DOI: 10.1089/zeb.2022.0029 -
Journal of the American Chemical Society Nov 1948
Topics: Methyltestosterone; Sterols
PubMed: 18102972
DOI: 10.1021/ja01191a101 -
Steroids Jan 2016Structural modifications of natural products with complex structures like steroids require great synthetic effort. A review of literature is presented on the chemistry... (Review)
Review
Structural modifications of natural products with complex structures like steroids require great synthetic effort. A review of literature is presented on the chemistry of the steroidal hormone 17α-methyltestosterone that is approved by Food and Drug Administration (FDA) in the United States as an androgen for estrogen-androgen hormone replacement therapy treatment. The analog also offers special possibilities for the prevention/treatment of hormone-sensitive cancers. The testosterone skeleton has important functionalities in the molecule that can act as a carbonyl component, an active methylene compound, α,β-unsaturated enone and tertiary hydroxyl group in various chemical reactions to access stereoisomeric steroidal compounds with potent activity. In addition, microbiological methods of synthesis and transformation of this hormone are presented.
Topics: Biotransformation; Hormones; Humans; Methyltestosterone
PubMed: 26639430
DOI: 10.1016/j.steroids.2015.11.004 -
Analytical Methods : Advancing Methods... Dec 2023Methyltestosterone is one of the banned drugs in aquaculture, and it should be monitored in food-producing animals. 17α-Methyl-5β-androstane-3α,17β-diol, as the main...
Methyltestosterone is one of the banned drugs in aquaculture, and it should be monitored in food-producing animals. 17α-Methyl-5β-androstane-3α,17β-diol, as the main metabolite of methyltestosterone in vertebrates, could be used as another marker for controlling the administration of methyltestosterone, due to its high residual concentration and slow elimination rate. In this study, an analytical method based on gas chromatography-mass spectrometry (GC-MS) was developed and validated for the simultaneous determination of methyltestosterone and its main metabolite in fish. After pretreatment by liquid-liquid extraction with -hexane and solid phase extraction with C and NH columns, the target analytes in the muscle tissues were extracted and concentrated, and the influence of the sample matrix was eliminated. Then, the prepared samples were separated and detected with GC-MS in the selected ion monitoring (SIM) mode. Methyltestosterone-D was chosen as the internal standard for quantitation. After optimization, the limits of detection for methyltestosterone and 17α-methyl-5β-androstane-3α,17β-diol were 20 μg kg and 15 μg kg, respectively. The limits of quantitation were both 50 μg kg. The calibration curves showed good linearity in the concentration range from 50.0 ng mL to 500.0 ng mL. The correlation coefficients of methyltestosterone and 17α-methyl-5β-androstane-3α,17β-diol were more than 0.9990. The recoveries of the analytes in real samples were in the range of 99.7-116.6% with the relative standard deviation of 5.2-8.3%. The established method could meet the demand for simultaneous detection of methyltestosterone and its major metabolite, and it could be used to provide more information on the abuse of methyltestosterone in food-producing animals.
Topics: Animals; Gas Chromatography-Mass Spectrometry; Methyltestosterone; Androstanes; Fishes; Calibration
PubMed: 38086623
DOI: 10.1039/d3ay01646c -
Nephron 1991
Topics: Cyclosporine; Drug Interactions; Humans; Kidney; Kidney Transplantation; Liver; Male; Methyltestosterone; Middle Aged
PubMed: 1944742
DOI: 10.1159/000186548 -
The Journal of Clinical Endocrinology... Jun 1953
Topics: Androgens; Methyltestosterone
PubMed: 13061593
DOI: 10.1210/jcem-13-6-732 -
Rapid Communications in Mass... Mar 2009Gas chromatography/mass spectrometry and selective derivatisation techniques have been used to identify urinary metabolites of methyltestosterone following oral...
Gas chromatography/mass spectrometry and selective derivatisation techniques have been used to identify urinary metabolites of methyltestosterone following oral administration to the greyhound. Several metabolites were identified including reduced, mono-, di- and trihydroxylated steroids. The major metabolites observed were 17alpha-methyl-5beta-androstane-3alpha-17beta-diol, 17alpha-methyl-5beta-androstane-3alpha,16alpha,17beta-triol, and a further compound tentatively identified as 17alpha-methyl-5z-androstane-6z,17beta-triol. The most abundant of these was the 17alpha-methyl-5beta-androstane-3alpha,16alpha,17beta-triol. This metabolite was identified by comparison with a reference standard synthesised using a Grignard procedure and characterised using trimethylsilyl (TMS) and acetonide-TMS derivatisation techniques. There did not appear to be any evidence for 16beta-hydroxylation as a phase I metabolic transformation in the greyhound. However, significant quantities of 16alpha-hydroxy metabolites were detected. Selective enzymatic hydrolysis procedures indicated that the major metabolites identified were excreted as glucuronic acid conjugates. Metabolic transformations observed in the greyhound have been compared with those of other mammalian species and are discussed here.
Topics: Administration, Oral; Animals; Dogs; Doping in Sports; Gas Chromatography-Mass Spectrometry; Methyltestosterone; Reproducibility of Results; Sensitivity and Specificity; Substance Abuse Detection; Urinalysis
PubMed: 19199316
DOI: 10.1002/rcm.3929 -
Drug Testing and Analysis 2014
Topics: Anabolic Agents; Doping in Sports; Gas Chromatography-Mass Spectrometry; Humans; Hydrolysis; Indicators and Reagents; Methyltestosterone; Reference Standards; Rhodococcus
PubMed: 25516451
DOI: 10.1002/dta.1761 -
General and Comparative Endocrinology Sep 2016Effects of xenobiotics can be organizational, permanently affecting anatomy during embryonic development, and/or activational, influencing transitory actions during...
Effects of xenobiotics can be organizational, permanently affecting anatomy during embryonic development, and/or activational, influencing transitory actions during adulthood. The organizational influence of endocrine-disrupting contaminants (EDC's) produces a wide variety of reproductive abnormalities among vertebrates that exhibit temperature-dependent sex determination (TSD). Typically, such influences result in subsequent activational malfunction, some of which are beneficial in aquaculture. For example, 17-αmethyltestosterone (MT), a synthetic androgen, is utilized in tilapia farming to bias sex ratio towards males because they are more profitable. A heavily male-biased hatchling sex ratio is reported from a crocodile population near one such tilapia operation in Guanacaste, Costa Rica. In this study we test the effects of MT on sexual differentiation in American alligators, which we used as a surrogate for all crocodilians. Experimentally, alligators were exposed to MT in ovo at standard ecotoxicological concentrations. Sexual differentiation was determined by examination of primary and secondary sex organs post hatching. We find that MT is capable of producing male embryos at temperatures known to produce females and demonstrate a dose-dependent gradient of masculinization. Embryonic exposure to MT results in hermaphroditic primary sex organs, delayed renal development and masculinization of the clitero-penis (CTP).
Topics: Alligators and Crocodiles; Animals; Female; Male; Methyltestosterone; Sex Determination Analysis; Sex Differentiation
PubMed: 27401264
DOI: 10.1016/j.ygcen.2016.07.007 -
Fish Physiology and Biochemistry Feb 2022A study was conducted to evaluate the gonad differentiation of juvenile yellow perch (YP, Perca flavencens) and determine the latest labile period related to hormone...
A study was conducted to evaluate the gonad differentiation of juvenile yellow perch (YP, Perca flavencens) and determine the latest labile period related to hormone treatment. Juvenile fish were subjected to two dietary concentrations of methyltestosterone (MT; 20 and 50 mg/kg feed) for 60 days in three (3) age groups of 38-, 46-, and 67-days post-hatching (dph), where control group were fed with standard commercial feed. Following a 10-month on-growing period, sex phenotypes were determined by gross and histological gonad morphology. Results showed the juvenile YP responded to the exogenous hormone when it was applied at 38 dph for both 20 and 50 mg/kg feed resulting in 100% males. At 46 dph, only 50 mg/kg feed resulted in 100% males. Both MT-treated at 38 and 46 dph significantly differed (P < 0.01) from the expected normal population of male:female (1:1). MT-treated at 67 dph resulted in 37% and 25% intersex fish for both 20 and 50 mg/kg feed dosage groups, respectively. MT-treated at 38 and 46 dph promoted growth and showed significantly heavier mean body weight (P < 0.05) compared to control. The gonadosomatic index (GSI) of MT-treated at 38 and 46 dph was significantly lower than that in control. This study provides the first evidence that juvenile YP can be successfully masculinized when the treatment is initiated at the age of up to 46 dph. The result is important for sex control in aquaculture.
Topics: Animals; Female; Gonads; Male; Methyltestosterone; Perches; Sex Differentiation
PubMed: 35039993
DOI: 10.1007/s10695-021-01038-0