Detection, pharmacokinetics and cardiac effects following administration of clenbuterol to exercised horses

Knych, Heather K.; Mitchell, M. M.; Steinmetz, S. J.; McKemie, Daniel S.

doi:10.1111/evj.12118

Cited by 6 publications

(5 citation statements)

References 22 publications

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“…Plasma was immediately transferred into storage cryovials (Phenix Research Products, Chandler, NC) and stored at −20 ° C until analysis. Drug concentrations were measured by Liquid Chromatography tandem Mass Spectrometry as described previously [ 13 ].…”

Section: Methodsmentioning

confidence: 99%

Differential expression of skeletal muscle genes following administration of clenbuterol to exercised horses

et al. 2016

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BackgroundClenbuterol, a beta2-adrenergic receptor agonist, is used therapeutically to treat respiratory conditions in the horse. However, by virtue of its mechanism of action it has been suggested that clenbuterol may also have repartitioning affects in horses and as such the potential to affect performance. Clenbuterol decreases the percent fat and increases fat-free mass following high dose administration in combination with intense exercise in horses. In the current study, microarray analysis and real-time PCR were used to study the temporal effects of low and high dose chronic clenbuterol administration on differential gene expression of several skeletal muscle myosin heavy chains, genes involved in lipid metabolism and the β2-adrenergic receptor. The effect of clenbuterol administration on differential gene expression has not been previously reported in the horse, therefore the primary objective of the current study was to describe clenbuterol-induced temporal changes in gene expression following chronic oral administration of clenbuterol at both high and low doses.ResultsSteady state clenbuterol concentrations were achieved at approximately 50 h post administration of the first dose for the low dose regimen and at approximately 18–19 days (10 days post administration of 3.2 μg/kg) for the escalating dosing regimen. Following chronic administration of the low dose (0.8 μg/kg BID) of clenbuterol, a total of 114 genes were differentially expressed, however, none of these changes were found to be significant following FDR adjustment of the p-values. A total of 7,093 genes were differentially expressed with 3,623 genes up regulated and 3,470 genes down regulated following chronic high dose administration. Of the genes selected for further study by real-time PCR, down-regulation of genes encoding myosin heavy chains 2 and 7, steroyl CoA desaturase and the β2-adrenergic receptor were noted. For most genes, expression levels returned towards baseline levels following cessation of drug administration.ConclusionThis study showed no evidence of modified gene expression following chronic low dose administration of clenbuterol to horses. However, following chronic administration of high doses of clenbuterol alterations were noted in transcripts encoding various myosin heavy chains, lipid metabolizing enzymes and the β2-adrenergic receptor.

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Section: Methodsmentioning

confidence: 99%

Differential expression of skeletal muscle genes following administration of clenbuterol to exercised horses

et al. 2016

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“…Profile concentrations of clenbuterol in the plasma were apparent in two intravascular compartment models as follows: In the central compartment, the clenbuterol is rapidly distributed throughout the body, and the drug is then gradually eliminated from the body as a peripheral compartment ( R 2 0.97-0.98). 5 min after dosing, the maximum concentration obtained was 19.232±0.331 µg/mL with elimination continuing rapidly as presented in Figure-4 [ 24 ]. A decreased mean concentration level of 3.84% resulted from the dose and produces initial concentration levels of less than the dose after 5 min posttreatment.…”

Section: Discussionmentioning

confidence: 99%

Calculate of withdrawal times of clenbuterol in goats to obtain safe times of slaughter

Lazuardi¹,

Hermanto²,

Restiadi³

2018

Vet World

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Background and Aim:Clenbuterol as a β2-agonist drug was investigated according to the concentration of the drug available in the bodies of goats and according to the level of sensitivity of the instruments used for detection. The objective of the current study was to determine withdrawal times after giving a therapeutic dose that resulted in safe slaughters.Materials and Methods:Five healthy male goats with a mean body weight of 20.64 kg were treated with a single dose of 5.10−3 mg/kg in the BW onto jugular vein. Whole blood samples of approximately 5 mL were taken in a time series at 5, 30, 60, 90, 150, 210, 270, 390, 510, 630, and 750 min. At 24 h posttreatment, all subjects were sacrificed, and 300 g samples of the liver were obtained. The plasma concentration and liver residue of the drug were observed by reverse-phase high-performance liquid chromatography.Results:The drug reached a maximum concentration of 19.233±0.331 µg/mL at 5 min, and the elimination half-life was at 173.25 min. The limit detection was obtained at 0.053 µg/mL. A one-way analysis of variance between all goats showed that elimination of the clenbuterol in their bodies was similar (p=1.00), with a withdrawal time of 1,479.326 min and no residues in the liver (p<0.05).Conclusion:Safe times for slaughter were determined to be at 2 days, 13 h, and 12 min as the 2nd safety factor (SF) time and 3 days, 1 h, and 58 min as the 3rd SF time with the liver organ free from residue.elimination half-life, new method for calculating withdrawal time, prescriptions for obtained β2-agonist, residues in liver.

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“…This group was named “drug group”. The drug selected was Ventipulmin® (Boehringer Ingelheim), a controlled drug used as a bronchodilator in veterinary. Following different athletics and bodybuilding blogs, in which they indicate that the regular administration of clenbuterol in cycles is pyramid‐shaped for 1–2 weeks, clenbuterol was pelleted in different concentrations.…”

Section: Methodsmentioning

confidence: 99%

Evaluation of R‐ (−) and S‐ (+) Clenbuterol enantiomers during a doping cycle or continuous ingestion of contaminated meat using chiral liquid chromatography by LC‐TQ‐MS

Dolores

Villaseñor

Piña-Olmos

et al. 2019

Drug Testing and Analysis

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Clenbuterol is known to improve competition resistance and muscular growth in athletes. Although it is an illegal drug, its use by farmers is widely spread to induce growth of their cattle. Thus, when clenbuterol is found in the urine of an athlete, there is doubt whether it was consumed with doping purposes or if it is due to the consumption of meat from a clenbuterol‐fed animal. Previous studies suggest that enantiomeric relationship of clenbuterol may be different according to the intake source. However, the enantiomeric relationship throughout a doping cycle or a continuous intake of contaminated meat has not yet been explored. In this first approximation, our aim was the development and validation of a sensitive and rapid method for the determination of S‐ (+) and R‐ (─) clenbuterol enantiomers to be used in a controlled study in rats fed for one week with contaminated meat or simulating a doping cycle. Enantiomers were measured using liquid chromatography coupled to mass spectrometry with a triple quadrupole analyzer (LC‐TQ‐MS) and were separated on an AGP Chiralpak column. The method was fully validated following the VICH (Veterinary International Conference on Harmonization guidelines) and was linear in the range of 12.5–800 pg/mL with a correlation coefficient of ≥0.98 for each enantiomer, and with a limit of quantitation and detection (LOQ and LOD) of 12.5 pg/mL and 6.5 pg/mL, respectively, for both enantiomers. The application of this method pointed out the shift of the enantiomeric relationship in urine from rats during the first five days of the doping cycle compared to those fed with contaminated meat. This finding can be of substantial importance in further doping studies.

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Detection, pharmacokinetics and cardiac effects following administration of clenbuterol to exercised horses

Cited by 6 publications

References 22 publications

Differential expression of skeletal muscle genes following administration of clenbuterol to exercised horses

Differential expression of skeletal muscle genes following administration of clenbuterol to exercised horses

Calculate of withdrawal times of clenbuterol in goats to obtain safe times of slaughter

Evaluation of R‐ (−) and S‐ (+) Clenbuterol enantiomers during a doping cycle or continuous ingestion of contaminated meat using chiral liquid chromatography by LC‐TQ‐MS

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