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Bruno Le Bizec - One of the best experts on this subject based on the ideXlab platform.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F Nielen, Bruno Le BizecAbstract:Abstract Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17β-estradiol 3-benzoate and 17β-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C 18 SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCα) for steroids were below 0.1 μg L −1 , except for 19-norandrosterone (CCα = 0.7 μg L −1 ) and estrone (CCα = 0.3 μg L −1 ). Kinetics of elimination of the administered 17β-estradiol 3-benzoate and 17β-Nandrolone laureate were established by monitoring 17β-estradiol, 17α-estradiol, estrone and 17β-Nandrolone, 17α-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17α-estradiol and 17α-Nandrolone (>20 and 2 mg L −1 , respectively after 17β-estradiol 3-benzoate and 17β-Nandrolone laureate administration) whereas 17β-estradiol, estrone, 17β-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the μg L −1 level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17β form.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F Nielen, Bruno Le BizecAbstract:Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C(18) SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCalpha) for steroids were below 0.1 microg L(-1), except for 19-norandrosterone (CCalpha=0.7 microg L(-1)) and estrone (CCalpha=0.3 microg L(-1)). Kinetics of elimination of the administered 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate were established by monitoring 17beta-estradiol, 17alpha-estradiol, estrone and 17beta-Nandrolone, 17alpha-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17alpha-estradiol and 17alpha-Nandrolone (>20 and 2 mg L(-1), respectively after 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate administration) whereas 17beta-estradiol, estrone, 17beta-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the microg L(-1) level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17beta form.
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endogenous Nandrolone metabolites in human urine preliminary results to discriminate between endogenous and exogenous origin
Steroids, 2002Co-Authors: Bruno Le Bizec, Fabrice Bryand, Isabelle Gaudin, Fabrice Monteau, Frederic Poulain, Francois AndreAbstract:When administered to human subjects, Nandrolone is metabolized into two main products, 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE). Recent studies demonstrated the endogenous production of these compounds in man at concentrations very close to the threshold of the International Olympic Committee (IOC), i.e. 2 ng/ml. Because the possibility of reaching or exceeding this fateful limit is difficult to exclude, a complementary biochemical parameter is necessary for the differentiation of endogenous 19-NA and 19-NE production from residues resulting from Nandrolone consumption. We measured the endogenous concentrations of 19-NA and 19-NE in 385 urine samples from professional football players, and we studied the phase II metabolite composition in individuals excreting the highest concentrations. The results showed that around 30% of endogenous 19-norandrosterone was sulfo-conjugated, whereas 100% of 19-norandrosterone was excreted conjugated to a glucuronic acid when Nandrolone was administered. This significant qualitative difference appears to be a promising complementary criterion to more definitively conclude about an athlete's culpability, especially when Nandrolone metabolites are found in the low ng/ml range.
Gaud Pinel - One of the best experts on this subject based on the ideXlab platform.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F NielenAbstract:Abstract Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17β-estradiol 3-benzoate and 17β-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C 18 SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCα) for steroids were below 0.1 μg L −1 , except for 19-norandrosterone (CCα = 0.7 μg L −1 ) and estrone (CCα = 0.3 μg L −1 ). Kinetics of elimination of the administered 17β-estradiol 3-benzoate and 17β-Nandrolone laureate were established by monitoring 17β-estradiol, 17α-estradiol, estrone and 17β-Nandrolone, 17α-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17α-estradiol and 17α-Nandrolone (>20 and 2 mg L −1 , respectively after 17β-estradiol 3-benzoate and 17β-Nandrolone laureate administration) whereas 17β-estradiol, estrone, 17β-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the μg L −1 level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17β form.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F Nielen, Bruno Le BizecAbstract:Abstract Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17β-estradiol 3-benzoate and 17β-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C 18 SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCα) for steroids were below 0.1 μg L −1 , except for 19-norandrosterone (CCα = 0.7 μg L −1 ) and estrone (CCα = 0.3 μg L −1 ). Kinetics of elimination of the administered 17β-estradiol 3-benzoate and 17β-Nandrolone laureate were established by monitoring 17β-estradiol, 17α-estradiol, estrone and 17β-Nandrolone, 17α-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17α-estradiol and 17α-Nandrolone (>20 and 2 mg L −1 , respectively after 17β-estradiol 3-benzoate and 17β-Nandrolone laureate administration) whereas 17β-estradiol, estrone, 17β-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the μg L −1 level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17β form.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F Nielen, Bruno Le BizecAbstract:Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C(18) SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCalpha) for steroids were below 0.1 microg L(-1), except for 19-norandrosterone (CCalpha=0.7 microg L(-1)) and estrone (CCalpha=0.3 microg L(-1)). Kinetics of elimination of the administered 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate were established by monitoring 17beta-estradiol, 17alpha-estradiol, estrone and 17beta-Nandrolone, 17alpha-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17alpha-estradiol and 17alpha-Nandrolone (>20 and 2 mg L(-1), respectively after 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate administration) whereas 17beta-estradiol, estrone, 17beta-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the microg L(-1) level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17beta form.
Michel W F Nielen - One of the best experts on this subject based on the ideXlab platform.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F NielenAbstract:Abstract Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17β-estradiol 3-benzoate and 17β-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C 18 SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCα) for steroids were below 0.1 μg L −1 , except for 19-norandrosterone (CCα = 0.7 μg L −1 ) and estrone (CCα = 0.3 μg L −1 ). Kinetics of elimination of the administered 17β-estradiol 3-benzoate and 17β-Nandrolone laureate were established by monitoring 17β-estradiol, 17α-estradiol, estrone and 17β-Nandrolone, 17α-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17α-estradiol and 17α-Nandrolone (>20 and 2 mg L −1 , respectively after 17β-estradiol 3-benzoate and 17β-Nandrolone laureate administration) whereas 17β-estradiol, estrone, 17β-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the μg L −1 level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17β form.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F Nielen, Bruno Le BizecAbstract:Abstract Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17β-estradiol 3-benzoate and 17β-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C 18 SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCα) for steroids were below 0.1 μg L −1 , except for 19-norandrosterone (CCα = 0.7 μg L −1 ) and estrone (CCα = 0.3 μg L −1 ). Kinetics of elimination of the administered 17β-estradiol 3-benzoate and 17β-Nandrolone laureate were established by monitoring 17β-estradiol, 17α-estradiol, estrone and 17β-Nandrolone, 17α-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17α-estradiol and 17α-Nandrolone (>20 and 2 mg L −1 , respectively after 17β-estradiol 3-benzoate and 17β-Nandrolone laureate administration) whereas 17β-estradiol, estrone, 17β-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the μg L −1 level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17β form.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F Nielen, Bruno Le BizecAbstract:Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C(18) SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCalpha) for steroids were below 0.1 microg L(-1), except for 19-norandrosterone (CCalpha=0.7 microg L(-1)) and estrone (CCalpha=0.3 microg L(-1)). Kinetics of elimination of the administered 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate were established by monitoring 17beta-estradiol, 17alpha-estradiol, estrone and 17beta-Nandrolone, 17alpha-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17alpha-estradiol and 17alpha-Nandrolone (>20 and 2 mg L(-1), respectively after 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate administration) whereas 17beta-estradiol, estrone, 17beta-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the microg L(-1) level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17beta form.
Fred Nyberg - One of the best experts on this subject based on the ideXlab platform.
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chronic administration of the anabolic androgenic steroid Nandrolone alters neurosteroid action at the sigma 1 receptor but not at the sigma 2 or nmda receptors
Neuropharmacology, 2011Co-Authors: Martin Elfverson, Tobias Johansson, Qin Zhou, Pierre Le Greves, Fred NybergAbstract:Abstract Studies have shown that anabolic androgenic steroids (AASs) can induce profound changes to mental health. Commonly reported psychiatric side effects among AAS users include aggression, anxiety, depression, drug abuse and cognitive disabilities. In experimental animals, many of these effects have been associated with alterations in a number of neurotransmitter systems. We have observed that chronic administration of the AAS Nandrolone (Nandrolone decanoate) can affect excitatory amino acids as well as monoaminergic and peptidergic pathways in a way that is compatible with Nandrolone-induced behavioural changes. The aim of the present work was to further explore the mechanisms underlying Nandrolone-induced effects, with a particular focus on components known to be involved in aggression and cognitive function. Male rats were given daily injections of Nandrolone decanoate for 14 days and the effects on neurosteroid interactions with sites on the N -methyl- d -aspartyl (NMDA) and sigma receptors were examined. These receptors were chosen because of their involvement in aggressive and cognitive behaviors and the hypothesis that Nandrolone might affect the brain via interaction with neurosteroids. Radiolabelled [ 3 H]ifenprodil was used in the binding studies because of its significant affinity for the NMDA and sigma receptors. The results indicated that [ 3 H]ifenprodil binds to both sigma-1 and sigma-2 sites and can be displaced to a certain extent from both sites by the neurosteroids pregnenolone sulphate (PS), pregnanolone sulphate (3α5βS) and dehydroepiandrosterone sulphate (DHEAS). The remainder of the [ 3 H]ifenprodil was displaced from the sigma-1 site by the sigma-1 receptor-selective ligand (+)-SKF 10,047. Chronic Nandrolone treatment changed the sigma-1 receptor target for the neurosteroids but not for ifenprodil. The sigma-2 receptor site was unaltered by treatment with Nandrolone decanoate. The results also indicated that the neurosteroid-induced allosteric modulation of the NMDA receptor subunit NR2B was not affected by Nandrolone treatment. We conclude that chronic treatment with Nandrolone changes the affinity of the neurosteroids PS, 3α5βS and DHEAS at the sigma-1 site but not at the sites on the sigma-2 receptor or the NMDA receptor subunit NR2B. This article is part of a Special Issue entitled ‘Synaptic Plasticity and Addiction’.
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Nandrolone decanoate administration elevates hippocampal prodynorphin mrna expression and impairs morris water maze performance in male rats
Neuroscience Letters, 2009Co-Authors: Kristina Magnusson, Qin Zhou, Anders Hanell, Igor Bazov, Fredrik Clausen, Fred NybergAbstract:The misuse of anabolic androgenic steroids has in several reports been associated with effects resulting in altered behavior. This study used the Morris water maze task to investigate the effect of high doses of the anabolic androgenic steroid Nandrolone on spatial learning and memory in male rats. During the experiment, we observed a significantly impaired Morris water maze performance in the Nandrolone-treated rats compared with controls. The hippocampus, a brain region associated with cognitive function, was analyzed for mRNA expression of prodynorphin, the precursor of dynorphinergic peptides. The results indicated that the transcription levels of prodynorphin were significantly elevated in the animals treated with Nandrolone compared with controls. Thus, the findings suggest that administration of Nandrolone to male rats impairs memory function, possibly via dynorphinergic actions.
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increased dopamine transporter density in the male rat brain following chronic Nandrolone decanoate administration
Neuroscience Letters, 2004Co-Authors: Anna M S Kindlundh, Sadia Rahman, Jonas Lindblom, Fred NybergAbstract:Adolescent males currently employ anabolic-androgenic steroids (AAS) to become intoxicated, besides the traditional desires of an improved physical appearance and enhanced sports performance. Several studies indicate that AAS affect the brain reward system. Recently chronic administration with Nandrolone decanoate to male rats has been shown to increase the dopamine transporter (DAT) density in the striatum visualised in vivo by positron emission tomography. The present study aimed to investigate if the increased DAT density could be confirmed using in vitro autoradiography following a comparable regimen of Nandrolone treatment. Specific binding of 50 pM [125I] RTI-55 in the presence of 1 microM citalopram was used to label DAT. Two weeks of Nandrolone decanoate administration at the supra-therapeutic doses 1, 5 and 15 mg/kg per day increased DAT density in the caudate putamen at all three doses. In conclusion, this study confirms that chronic Nandrolone administration increases dopamine transporter density in the CPU and therefore supports the theory that AAS affects the dopamine system in the male rat brain.
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effects of Nandrolone on acute morphine responses tolerance and dependence in mice
European Journal of Pharmacology, 2003Co-Authors: Evelyne Celerier, Fred Nyberg, Maryam T Yazdi, Anna Castane, Sandy Ghozland, Rafael MaldonadoAbstract:Abstract Anabolic–androgenic steroid exposure has been proposed to present a risk factor for the misuse of other drugs of abuse. We now examined whether the exposure to the anabolic–androgenic steroid, Nandrolone, would affect the acute morphine responses, tolerance and dependence in rodents. For this purpose, mice received Nandrolone using pre-exposure (for 14 days before morphine experiments) or co-administration (1 h before each morphine injection) procedures. Nandrolone treatments increased the acute hypothermic effects of morphine without modifying its acute antinociceptive and locomotor effects. Nandrolone also attenuated the development of tolerance to morphine antinociception in the hot plate test, but did not affect tolerance to its hypothermic effects, nor the sensitisation to morphine locomotor responses. After Nandrolone pre-exposure, we observed an attenuation of morphine-induced place preference and an increase in the somatic manifestations of naloxone-precipitated morphine withdrawal. These results indicate that anabolic–androgenic steroid consumption may induce adaptations in neurobiological systems implicated in the development of morphine dependence.
Aldert A Bergwerff - One of the best experts on this subject based on the ideXlab platform.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F NielenAbstract:Abstract Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17β-estradiol 3-benzoate and 17β-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C 18 SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCα) for steroids were below 0.1 μg L −1 , except for 19-norandrosterone (CCα = 0.7 μg L −1 ) and estrone (CCα = 0.3 μg L −1 ). Kinetics of elimination of the administered 17β-estradiol 3-benzoate and 17β-Nandrolone laureate were established by monitoring 17β-estradiol, 17α-estradiol, estrone and 17β-Nandrolone, 17α-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17α-estradiol and 17α-Nandrolone (>20 and 2 mg L −1 , respectively after 17β-estradiol 3-benzoate and 17β-Nandrolone laureate administration) whereas 17β-estradiol, estrone, 17β-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the μg L −1 level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17β form.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F Nielen, Bruno Le BizecAbstract:Abstract Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17β-estradiol 3-benzoate and 17β-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C 18 SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCα) for steroids were below 0.1 μg L −1 , except for 19-norandrosterone (CCα = 0.7 μg L −1 ) and estrone (CCα = 0.3 μg L −1 ). Kinetics of elimination of the administered 17β-estradiol 3-benzoate and 17β-Nandrolone laureate were established by monitoring 17β-estradiol, 17α-estradiol, estrone and 17β-Nandrolone, 17α-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17α-estradiol and 17α-Nandrolone (>20 and 2 mg L −1 , respectively after 17β-estradiol 3-benzoate and 17β-Nandrolone laureate administration) whereas 17β-estradiol, estrone, 17β-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the μg L −1 level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17β form.
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elimination kinetic of 17b estradiol 3 benzoate and 17b Nandrolone laureate ester metabolites in calves urine
The Journal of Steroid Biochemistry and Molecular Biology, 2008Co-Authors: Gaud Pinel, Lauriane Rambaud, G Cacciatore, Aldert A Bergwerff, Christopher T Elliott, Michel W F Nielen, Bruno Le BizecAbstract:Efficient control of the illegal use of anabolic steroids must both take into account metabolic patterns and associated kinetics of elimination; in this context, an extensive animal experiment involving 24 calves and consisting of three administrations of 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate esters was carried out over 50 days. Urine samples were regularly collected during the experiment from all treated and non-treated calves. For sample preparation, a single step high throughput protocol based on 96-well C(18) SPE was developed and validated according to the European Decision 2002/657/EC requirements. Decision limits (CCalpha) for steroids were below 0.1 microg L(-1), except for 19-norandrosterone (CCalpha=0.7 microg L(-1)) and estrone (CCalpha=0.3 microg L(-1)). Kinetics of elimination of the administered 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate were established by monitoring 17beta-estradiol, 17alpha-estradiol, estrone and 17beta-Nandrolone, 17alpha-Nandrolone, 19-noretiocholanolone, 19-norandrostenedione, respectively. All animals demonstrated homogeneous patterns of elimination both from a qualitative (metabolite profile) and quantitative point of view (elimination kinetics in urine). Most abundant metabolites were 17alpha-estradiol and 17alpha-Nandrolone (>20 and 2 mg L(-1), respectively after 17beta-estradiol 3-benzoate and 17beta-Nandrolone laureate administration) whereas 17beta-estradiol, estrone, 17beta-Nandrolone, 19-noretiocholanolone and 19-norandrostenedione were found as secondary metabolites at concentration values up to the microg L(-1) level. No significant difference was observed between male and female animals. The effect of several consecutive injections on elimination profiles was studied and revealed a tendency toward a decrease in the biotransformation of administered steroid 17beta form.
