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Hiroyuki Nakazawa - One of the best experts on this subject based on the ideXlab platform.
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Short Communication I Detection of Urinary Metabolites Common to Structurally Related 17a-Alkyl Anabolic Steroids in Horses and Application to Doping Tests in Racehorses:
2016Co-Authors: Masayuki Yamada, Sugako Aramaki, Masahiko Kurosawa, Koichi Saito, Hiroyuki NakazawaAbstract:Abstract] Methandienone, methandriol, and oxymetholone, which are anabolic steroids possessing 1 7a-methyl and 171S-hydroxy groups, were developed as oral formulations for therapeutic purposes. However, they have been used in racehorses to enhance racing performance. In humans, it has been reported that structurally related anabolic steroids having the 17a-methyl and 171~hydroxy groups, including 17a-Methyltestosterone, mestanolone, methandienone, methandriol, and oxymetholone, have metabolites in common. In this study, we found that metabolites common to those of 17a-Methyltestosterone and mestanolone were detected in horse urine after the administration of oxymetholone, methandienone, and methandriol. Based on analytical data, we confirmed these to be the common metabolites of five structurally related steroids, 17o.-Methyltestosterone, mestanolone, oxymetholone, methandienone, and methandriol. Furthermore, wedetected hitherto unknown urinary metabolites of methandriol and oxymetholone in horses. The parent steroid itself was detected in horse urine after the administration of methandriol, other than metabolites common to 17a-Methyltestosterone and mestanolone. O the other hand, the major metabolite of oxymetholone was mestanolone, aside from metabolites presumed to be the stereoisomers of 2-hydroxymethyl-17o.-methyl-5o.-androstan-3,17l]-diol and 2,1 7a-di(hydroxymethyl)-5a-androstan-3,1 71~-diol. The simultaneous detection f common metabolites and other main metabolites would help us narrow down the candidate-administered steroid for the doping tests in racehorses
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Detection of Urinary Metabolites Common to Structurally Related 17α-Alkyl Anabolic Steroids in Horses and Application to Doping Tests in Racehorses: Methandienone, Methandriol, and Oxymetholone
Journal of analytical toxicology, 2008Co-Authors: Masayuki Yamada, Sugako Aramaki, Masahiko Kurosawa, Koichi Saito, Hiroyuki NakazawaAbstract:Methandienone, methandriol, and oxymetholone, which are anabolic steroids possessing 17alpha-methyl and 17beta-hydroxy groups, were developed as oral formulations for therapeutic purposes. However, they have been used in racehorses to enhance racing performance. In humans, it has been reported that structurally related anabolic steroids having the 17alpha-methyl and 17beta-hydroxy groups, including 17alpha-Methyltestosterone, mestanolone, methandienone, methandriol, and oxymetholone, have metabolites in common. In this study, we found that metabolites common to those of 17alpha-Methyltestosterone and mestanolone were detected in horse urine after the administration of oxymetholone, methandienone, and methandriol. Based on analytical data, we confirmed these to be the common metabolites of five structurally related steroids, 17alpha-Methyltestosterone, mestanolone, oxymetholone, methandienone, and methandriol. Furthermore, we detected hitherto unknown urinary metabolites of methandriol and oxymetholone in horses. The parent steroid itself was detected in horse urine after the administration of methandriol, other than metabolites common to 17alpha-Methyltestosterone and mestanolone. On the other hand, the major metabolite of oxymetholone was mestanolone, aside from metabolites presumed to be the stereoisomers of 2-hydroxymethyl-17alpha-methyl-5alpha-androstan-3,17beta-diol and 2,17alpha-di(hydroxymethyl)-5alpha-androstan-3,17beta-diol. The simultaneous detection of common metabolites and other main metabolites would help us narrow down the candidate-administered steroid for the doping tests in racehorses.
N. E. Voishvillo - One of the best experts on this subject based on the ideXlab platform.
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Conversion of 17α-Methyltestosterone to methandrostenolone by the bacterium pimelobacter simplex VKPM Ac-1632 with the presence of cyclodextrins
Applied Biochemistry and Microbiology, 2008Co-Authors: A. V. Druzhinina, V. A. Andryushina, T. S. Stytsenko, N. E. VoishvilloAbstract:Conditions of conversion of 17α-Methyltestosterone to methandrostenolone with the presence of modified β-cyclodextrins (methylcyclodextrin, hydroxypropylcyclodextrin, and hydroxyethylcyclodextrin) in the steroid: cyclodextrin ratio 1: 1 were studied. The experimental solutions of modified β-cyclodextrins were prepared in deionized water with 5–7% methanol. Under the conditions found to be optimal, 1,2–dehydrogenation of 17α-Methyltestosterone was carried out with 2–4 g/l Pimelobacter simplex VKPM Ac-1632 biomass. At the substrate concentration 5–20 g/l, the reaction occurred for 1–15 h without any by-products. The maximum rate of methandrostenolone accumulation was observed with hydroxypropylcyclodextrin. The methylcyclodextrin solution can be reused for complete 17α-Methyltestosterone conversion at the concentration 5 g/l.
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Conversion of 17α-Methyltestosterone to methandrostenolone by the bacterium pimelobacter simplex VKPM Ac-1632 with the presence of cyclodextrins
Applied Biochemistry and Microbiology, 2008Co-Authors: A. V. Druzhinina, V. A. Andryushina, T. S. Stytsenko, N. E. VoishvilloAbstract:Conditions of conversion of 17 alpha-Methyltestosterone to methandrostenolone with the presence of modified beta-cyclodextrins (methylcyclodextrin, hydroxypropylcyclodextrin, and hydroxyethylcyclodextrin) in the steroid:cyclodextrin ratio 1:1 were studied. The experimental solutions of modified beta-cyclodextrins were prepared in deionized water with 5-7% methanol. Under the conditions found to be optimal, 1,2-dehydrogenation of 17 alpha-Methyltestosterone was carried out with 2-4 g/l Pimelobacter simplex VKPM Ac-1632 biomass. At the substrate concentration 5-20 g/l, the reaction occurred for 1-15 h without any by-products. The maximum rate of methandrostenolone accumulation was observed with hydroxypropylcyclodextrin. The methylcyclodextrin solution can be reused for complete 17 alpha-Methyltestosterone conversion at the concentration 5 g/l.
A. V. Druzhinina - One of the best experts on this subject based on the ideXlab platform.
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Conversion of 17α-Methyltestosterone to methandrostenolone by the bacterium pimelobacter simplex VKPM Ac-1632 with the presence of cyclodextrins
Applied Biochemistry and Microbiology, 2008Co-Authors: A. V. Druzhinina, V. A. Andryushina, T. S. Stytsenko, N. E. VoishvilloAbstract:Conditions of conversion of 17α-Methyltestosterone to methandrostenolone with the presence of modified β-cyclodextrins (methylcyclodextrin, hydroxypropylcyclodextrin, and hydroxyethylcyclodextrin) in the steroid: cyclodextrin ratio 1: 1 were studied. The experimental solutions of modified β-cyclodextrins were prepared in deionized water with 5–7% methanol. Under the conditions found to be optimal, 1,2–dehydrogenation of 17α-Methyltestosterone was carried out with 2–4 g/l Pimelobacter simplex VKPM Ac-1632 biomass. At the substrate concentration 5–20 g/l, the reaction occurred for 1–15 h without any by-products. The maximum rate of methandrostenolone accumulation was observed with hydroxypropylcyclodextrin. The methylcyclodextrin solution can be reused for complete 17α-Methyltestosterone conversion at the concentration 5 g/l.
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Conversion of 17α-Methyltestosterone to methandrostenolone by the bacterium pimelobacter simplex VKPM Ac-1632 with the presence of cyclodextrins
Applied Biochemistry and Microbiology, 2008Co-Authors: A. V. Druzhinina, V. A. Andryushina, T. S. Stytsenko, N. E. VoishvilloAbstract:Conditions of conversion of 17 alpha-Methyltestosterone to methandrostenolone with the presence of modified beta-cyclodextrins (methylcyclodextrin, hydroxypropylcyclodextrin, and hydroxyethylcyclodextrin) in the steroid:cyclodextrin ratio 1:1 were studied. The experimental solutions of modified beta-cyclodextrins were prepared in deionized water with 5-7% methanol. Under the conditions found to be optimal, 1,2-dehydrogenation of 17 alpha-Methyltestosterone was carried out with 2-4 g/l Pimelobacter simplex VKPM Ac-1632 biomass. At the substrate concentration 5-20 g/l, the reaction occurred for 1-15 h without any by-products. The maximum rate of methandrostenolone accumulation was observed with hydroxypropylcyclodextrin. The methylcyclodextrin solution can be reused for complete 17 alpha-Methyltestosterone conversion at the concentration 5 g/l.
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Conversion of 17 alpha-Methyltestosterone to methandrostenolone by the bacterium Pimelobacter simplex VKPM Ac-1632 with the presence of cyclodextrins
Prikladnaia biokhimiia i mikrobiologiia, 2008Co-Authors: A. V. Druzhinina, T. S. Stytsenko, V A Andriushina, N E VoĭshvilloAbstract:Conditions of conversion of 17 alpha-Methyltestosterone to methandrostenolone with the presence of modified beta-cyclodextrins (methylcyclodextrin, hydroxypropylcyclodextrin, and hydroxyethylcyclodextrin) in the steroid:cyclodextrin ratio 1:1 were studied. The experimental solutions of modified beta-cyclodextrins were prepared in deionized water with 5-7% methanol. Under the conditions found to be optimal, 1,2-dehydrogenation of 17 alpha-Methyltestosterone was carried out with 2-4 g/l Pimelobacter simplex VKPM Ac-1632 biomass. At the substrate concentration 5-20 g/l, the reaction occurred for 1-15 h without any by-products. The maximum rate of methandrostenolone accumulation was observed with hydroxypropylcyclodextrin. The methylcyclodextrin solution can be reused for complete 17 alpha-Methyltestosterone conversion at the concentration 5 g/l.
William L. Hayton - One of the best experts on this subject based on the ideXlab platform.
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Methyltestosterone pharmacolinetics and oral bioavailability in rainbow trout (Oncorhynchus mykiss)
Aquatic Toxicology, 2001Co-Authors: Andrew M. Vick, William L. HaytonAbstract:Abstract 14 C-Methyltestosterone pharmacokinetics after intraarterial (2 and 20 mg/kg) and oral (30 mg/kg) administration were investigated in rainbow trout at 15°C. Plasma concentrations of Methyltestosterone were determined by reverse phase high performance liquid chromatography (HPLC) in combination with reverse isotope dilution for upto 6 and 12 days after oral and intraarterial administration, respectively. Methyltestosterone pharmacokinetic parameter values after intraarterial administration were determined using a two compartment model (WinNonlin). For the 2 and 20 mg/kg doses, respectively, the parameter values were, area under the plasma concentration–time curve (11.2 and 82.3 μmol h/l), total body clearance (0.640 and 0.903 l/h per kg), distribution half-life (4.13 and 8.23 h), elimination half-life (54.9 and 58.6 h), volume of the central compartment (3.83 and 13.9 l/kg), volume of distribution at steady state (6.06 and 26.8 l/kg), and the mean residence time (9.57 and 22.7 h). After oral administration, the following parameter values were assessed using a model-independent method, peak concentration (3.03 μmol/l), time of concentration peak (8.80 h), mean absorption time (13.8 h), and area under curve (AUC) 0→∞ (90.2 μmol h/l). A two compartment model analysis of the average plasma concentration–time profile after oral administration showed that absorption followed first-order kinetics with a half-life of 4.7 h. The oral bioavailability of Methyltestosterone from food was about 70%.
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Methyltestosterone pharmacolinetics and oral bioavailability in rainbow trout (Oncorhynchus mykiss)
2001Co-Authors: Andrew M. Vick, William L. HaytonAbstract:4C-Methyltestosterone pharmacokinetics after intraarterial (2 and 20 mg/kg) and oral (30 mg/kg) administration were investigated in rainbow trout at 15°C. Plasma concentrations of Methyltestosterone were determined by reverse phase high performance liquid chromatography (HPLC) in combination with reverse isotope dilution for upto 6 and 12 days after oral and intraarterial administration, respectively. Methyltestosterone pharmacokinetic parameter values after intraarterial administration were determined using a two compartment model (WinNonlin). For the 2 and 20 mg/kg doses, respectively, the parameter values were, area under the plasma concentration-time curve (11.2 and 82.3 μmol h/l), total body elearance (0.640 and 0.903 l/h per kg), distribution half-life (4.13 and 8.23 h), elimination half-life (54.9 and 58.6 h), volume of the central compartment (3.83 and 13.9 l/kg), volume of distribution at steady state (6.06 and 26.8 l/kg), and the mean residence time (9.57 and 22.7 h). After oral administration, the following parameter values were assessed using a model-independent method, peak concentration (3.03 μmol/l), time of concentration peak (8.80 h), mean absorption time (13.8 h), and area under curve (AUC) 0 → c (90.2 μmol h/l). A two compartment model analysis of the average plasma concentration-time profile after oral administration showed that absorption followed first-order kinetics with a half-life of 4.7 h. The oral bioavailability of Methyltestosterone from food was about 70%.
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Methyltestosterone pharmacokinetics and oral bioavailability in rainbow trout (Oncorhynchus mykiss).
Aquatic toxicology (Amsterdam Netherlands), 2001Co-Authors: Andrew M. Vick, William L. HaytonAbstract:14C-Methyltestosterone pharmacokinetics after intraarterial (2 and 20 mg/kg) and oral (30 mg/kg) administration were investigated in rainbow trout at 15 degrees C. Plasma concentrations of Methyltestosterone were determined by reverse phase high performance liquid chromatography (HPLC) in combination with reverse isotope dilution for up to 6 and 12 days after oral and intraarterial administration, respectively. Methyltestosterone pharmacokinetic parameter values after intraarterial administration were determined using a two compartment model (WinNonlin). For the 2 and 20 mg/kg doses, respectively, the parameter values were, area under the plasma concentration-time curve (11.2 and 82.3 micromol h/l), total body clearance (0.640 and 0.903 l/h per kg), distribution half-life (4.13 and 8.23 h), elimination half-life (54.9 and 58.6 h), volume of the central compartment (3.83 and 13.9 l/kg), volume of distribution at steady state (6.06 and 26.8 l/kg), and the mean residence time (9.57 and 22.7 h). After oral administration, the following parameter values were assessed using a model-independent method, peak concentration (3.03 micromol/l), time of concentration peak (8.80 h), mean absorption time (13.8 h), and area under curve (AUC)(0-->infinity) (90.2 micromol h/l). A two compartment model analysis of the average plasma concentration-time profile after oral administration showed that absorption followed first-order kinetics with a half-life of 4.7 h. The oral bioavailability of Methyltestosterone from food was about 70%.
Ralph A. Defronzo - One of the best experts on this subject based on the ideXlab platform.
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Effects of Methyltestosterone on insulin secretion and sensitivity in women.
The Journal of clinical endocrinology and metabolism, 1998Co-Authors: Michael P. Diamond, David A. Grainger, Meredith C. Diamond, Robert S. Sherwin, Ralph A. DefronzoAbstract:The frequent coexistence of hyperandrogenism and insulin resistance is well established; however, whether a cause and effect relationship exists remains to be established. In this study we tested the hypothesis that short-term androgen administered to women would induce insulin resistance. To test this hypothesis, regularly menstruating, nonobese women were studied before and during Methyltestosterone administration (5 mg tid for 10–12 days) by the hyperglycemic (n = 8) and euglycemic, hyperinsulinemic (n = 7) clamp techniques. Short-term Methyltestosterone administration had no significant effects on the fasting levels of glucose, insulin, c-peptide, glucagon, or glucose turnover. During the hyperglycemic clamp studies, the mean glucose level during the final hour was 203 ± 2 and 201 ± 1 mg/dL in the Methyltestosterone and control studies, respectively. The insulin response to this hyperglycemic challenge was slightly but not significantly greater during Methyltestosterone treatment (first phase 59 ± 8 v...