Beta2-adrenergic agonist clenbuterol increases energy expenditure and fat oxidation, and induces mTOR phosphorylation in skeletal muscle of young healthy men

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Standard

Beta2-adrenergic agonist clenbuterol increases energy expenditure and fat oxidation, and induces mTOR phosphorylation in skeletal muscle of young healthy men. / Jessen, Søren; Solheim, Sara Amalie; Jacobson, Glenn A; Eibye, Kasper Hvid; Bangsbo, Jens; Nordsborg, Nikolai Baastrup; Hostrup, Morten.

I: Drug Testing and Analysis, Bind 12, Nr. 5, 2020, s. 610-618.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Harvard

Jessen, S, Solheim, SA, Jacobson, GA, Eibye, KH, Bangsbo, J, Nordsborg, NB & Hostrup, M 2020, 'Beta2-adrenergic agonist clenbuterol increases energy expenditure and fat oxidation, and induces mTOR phosphorylation in skeletal muscle of young healthy men', Drug Testing and Analysis, bind 12, nr. 5, s. 610-618. https://doi.org/10.1002/dta.2755

APA

Jessen, S., Solheim, S. A., Jacobson, G. A., Eibye, K. H., Bangsbo, J., Nordsborg, N. B., & Hostrup, M. (2020). Beta2-adrenergic agonist clenbuterol increases energy expenditure and fat oxidation, and induces mTOR phosphorylation in skeletal muscle of young healthy men. Drug Testing and Analysis, 12(5), 610-618. https://doi.org/10.1002/dta.2755

Vancouver

Jessen S, Solheim SA, Jacobson GA, Eibye KH, Bangsbo J, Nordsborg NB o.a. Beta2-adrenergic agonist clenbuterol increases energy expenditure and fat oxidation, and induces mTOR phosphorylation in skeletal muscle of young healthy men. Drug Testing and Analysis. 2020;12(5):610-618. https://doi.org/10.1002/dta.2755

Author

Jessen, Søren ; Solheim, Sara Amalie ; Jacobson, Glenn A ; Eibye, Kasper Hvid ; Bangsbo, Jens ; Nordsborg, Nikolai Baastrup ; Hostrup, Morten. / Beta2-adrenergic agonist clenbuterol increases energy expenditure and fat oxidation, and induces mTOR phosphorylation in skeletal muscle of young healthy men. I: Drug Testing and Analysis. 2020 ; Bind 12, Nr. 5. s. 610-618.

Bibtex

@article{9c675c0493224924a682cd4ab34612d0,
title = "Beta2-adrenergic agonist clenbuterol increases energy expenditure and fat oxidation, and induces mTOR phosphorylation in skeletal muscle of young healthy men",
abstract = "Clenbuterol is a beta2-adrenoceptor agonist marketed as an asthma reliever but is not approved for human use in most countries due to concerns of adverse cardiac effects. Given its demonstrated hypertrophic and lipolytic actions in rodents, clenbuterol is one of the most widely abused doping substances amongt athletes and recreational body-builders seeking leanness. Herein, we examined the effect of clenbuterol ingestion on metabolic rate as well as skeletal muscle mammalian target of rapamycin (mTOR) phosphorylation and protein kinase A (PKA)-signaling in six young men. Before and 140 min after ingestion of 80 μg clenbuterol, resting metabolic rate and contractile function of the quadriceps muscle were measured, and blood samples as well as vastus lateralis muscle biopsies were collected. Clenbuterol increased resting energy expenditure by 21{\%} (P < 0.001), and fat oxidation by 39{\%} (P = 0.006), whereas carbohydrate oxidation was unchanged. Phosphorylation of mTORSer2448 and PKA substrates increased by 121{\%} (P = 0.004) and 35{\%} (P = 0.006), respectively, with clenbuterol. Maximal voluntary contraction torque decreased by 4{\%} (P = 0.026) and the half-relaxation time shortened by 9{\%} (P = 0.046), while voluntary activation, time to peak twitch, and peak twitch torque did not change significantly with clenbuterol. Glycogen content of the vastus lateralis muscle did not change with clenbuterol. Clenbuterol increased circulating levels of glucose (+30{\%}; P < 0.001), lactate (+90{\%}; P = 0.004), insulin (+130{\%}; P = 0.009), and fatty acids (+180{\%}; P = 0.001). Collectively, these findings indicate that clenbuterol is an efficient thermogenic substance that possibly also exerts muscle hypertrophic actions in humans. For these reasons, the restrictions imposed against clenbuterol in competitive sports seem warranted.",
keywords = "Faculty of Science, Doping, WADA, Muscle hypertrophy, Muscle growth, Anabolic",
author = "S{\o}ren Jessen and Solheim, {Sara Amalie} and Jacobson, {Glenn A} and Eibye, {Kasper Hvid} and Jens Bangsbo and Nordsborg, {Nikolai Baastrup} and Morten Hostrup",
note = "{\circledC} 2019 John Wiley & Sons, Ltd.",
year = "2020",
doi = "10.1002/dta.2755",
language = "English",
volume = "12",
pages = "610--618",
journal = "Drug Testing and Analysis",
issn = "1942-7603",
publisher = "JohnWiley & Sons Ltd",
number = "5",

}

RIS

TY - JOUR

T1 - Beta2-adrenergic agonist clenbuterol increases energy expenditure and fat oxidation, and induces mTOR phosphorylation in skeletal muscle of young healthy men

AU - Jessen, Søren

AU - Solheim, Sara Amalie

AU - Jacobson, Glenn A

AU - Eibye, Kasper Hvid

AU - Bangsbo, Jens

AU - Nordsborg, Nikolai Baastrup

AU - Hostrup, Morten

N1 - © 2019 John Wiley & Sons, Ltd.

PY - 2020

Y1 - 2020

N2 - Clenbuterol is a beta2-adrenoceptor agonist marketed as an asthma reliever but is not approved for human use in most countries due to concerns of adverse cardiac effects. Given its demonstrated hypertrophic and lipolytic actions in rodents, clenbuterol is one of the most widely abused doping substances amongt athletes and recreational body-builders seeking leanness. Herein, we examined the effect of clenbuterol ingestion on metabolic rate as well as skeletal muscle mammalian target of rapamycin (mTOR) phosphorylation and protein kinase A (PKA)-signaling in six young men. Before and 140 min after ingestion of 80 μg clenbuterol, resting metabolic rate and contractile function of the quadriceps muscle were measured, and blood samples as well as vastus lateralis muscle biopsies were collected. Clenbuterol increased resting energy expenditure by 21% (P < 0.001), and fat oxidation by 39% (P = 0.006), whereas carbohydrate oxidation was unchanged. Phosphorylation of mTORSer2448 and PKA substrates increased by 121% (P = 0.004) and 35% (P = 0.006), respectively, with clenbuterol. Maximal voluntary contraction torque decreased by 4% (P = 0.026) and the half-relaxation time shortened by 9% (P = 0.046), while voluntary activation, time to peak twitch, and peak twitch torque did not change significantly with clenbuterol. Glycogen content of the vastus lateralis muscle did not change with clenbuterol. Clenbuterol increased circulating levels of glucose (+30%; P < 0.001), lactate (+90%; P = 0.004), insulin (+130%; P = 0.009), and fatty acids (+180%; P = 0.001). Collectively, these findings indicate that clenbuterol is an efficient thermogenic substance that possibly also exerts muscle hypertrophic actions in humans. For these reasons, the restrictions imposed against clenbuterol in competitive sports seem warranted.

AB - Clenbuterol is a beta2-adrenoceptor agonist marketed as an asthma reliever but is not approved for human use in most countries due to concerns of adverse cardiac effects. Given its demonstrated hypertrophic and lipolytic actions in rodents, clenbuterol is one of the most widely abused doping substances amongt athletes and recreational body-builders seeking leanness. Herein, we examined the effect of clenbuterol ingestion on metabolic rate as well as skeletal muscle mammalian target of rapamycin (mTOR) phosphorylation and protein kinase A (PKA)-signaling in six young men. Before and 140 min after ingestion of 80 μg clenbuterol, resting metabolic rate and contractile function of the quadriceps muscle were measured, and blood samples as well as vastus lateralis muscle biopsies were collected. Clenbuterol increased resting energy expenditure by 21% (P < 0.001), and fat oxidation by 39% (P = 0.006), whereas carbohydrate oxidation was unchanged. Phosphorylation of mTORSer2448 and PKA substrates increased by 121% (P = 0.004) and 35% (P = 0.006), respectively, with clenbuterol. Maximal voluntary contraction torque decreased by 4% (P = 0.026) and the half-relaxation time shortened by 9% (P = 0.046), while voluntary activation, time to peak twitch, and peak twitch torque did not change significantly with clenbuterol. Glycogen content of the vastus lateralis muscle did not change with clenbuterol. Clenbuterol increased circulating levels of glucose (+30%; P < 0.001), lactate (+90%; P = 0.004), insulin (+130%; P = 0.009), and fatty acids (+180%; P = 0.001). Collectively, these findings indicate that clenbuterol is an efficient thermogenic substance that possibly also exerts muscle hypertrophic actions in humans. For these reasons, the restrictions imposed against clenbuterol in competitive sports seem warranted.

KW - Faculty of Science

KW - Doping

KW - WADA

KW - Muscle hypertrophy

KW - Muscle growth

KW - Anabolic

U2 - 10.1002/dta.2755

DO - 10.1002/dta.2755

M3 - Journal article

C2 - 31887249

VL - 12

SP - 610

EP - 618

JO - Drug Testing and Analysis

JF - Drug Testing and Analysis

SN - 1942-7603

IS - 5

ER -

ID: 237471275