Chronic clenbuterol administration negatively alters cardiac function.
Abstract: Chronic administration of pharmacological levels of beta2-agonists have been shown to have toxic effects on the heart; however, no data exist on cardiac function after chronic clenbuterol administration. The purpose of this study was to examine the effect of therapeutic levels of clenbuterol on cardiac performance. Methods: Twenty unfit Standardbred mares were divided into four experimental groups: clenbuterol (2.4 microg.kg(-1) twice daily 5 d.wk(-1)) plus exercise (20 min at 50% .VO(2max)) (CLENEX; N = 6), clenbuterol (CLEN; N = 6), exercise (EX; N = 4), and control (CON; N = 4). M-mode and two-dimensional echocardiography (2.5-MHz sector scanner transducer) were used to measure cardiac size and function before and immediately after an incremental exercise test, before and after 8 wk of drug and/or exercise treatments. Results: After treatment, CLENEX and CLEN demonstrated significantly higher left ventricular internal dimension (LVD) at end diastole (+23.7 +/- 4.8%; +25.6 +/- 4.1%), LVD at end systole (+29.2 +/- 8.7%; +40.1 +/- 7.9%), interventricular septal wall thickness (IVS) at end diastole (+28.9 +/- 11.0%; +30.7 +/- 7.0%), IVS at end systole (+29.2 +/- 8.7%; +40.1 +/- 7.9%), and left ventricular posterior wall systolic thickness (+43.1 +/- 14.%; +45.8 +/- 14.1%). CLENEX and CLEN had significantly increased aortic root dimensions (+29.9 +/- 6.1%; +24.0 +/- 1.7%), suggesting increased risk of aortic rupture. Conclusions: Taken together, these data indicate that chronic clenbuterol administration may negatively alter cardiac function.
Publication Date: 2002-04-05 PubMed ID: 11932573DOI: 10.1097/00005768-200204000-00013Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The study investigates the impact of chronic clenbuterol use on cardiac performance, showing that chronic administration of clenbuterol can have detrimental effects on heart function.
Study Design and Method
- The study involved 20 unfit Standardbred mares split into four groups: clenbuterol with exercise (CLENEX), clenbuterol only (CLEN), exercise only (EX), and a control group with no intervention (CON).
- The quantity of clenbuterol administered was fixed at therapeutic levels (2.4 microg.kg(-1) twice daily 5 d.wk(-1)).
- The exercise incorporated was for 20 minutes at 50% .VO(2max).
- Using M-mode and two-dimensional echocardiography, researchers measured cardiac size and function before and after an incremental exercise test, before and after 8 weeks of drug and/or exercise treatments.
Study Results
- The groups with clenbuterol administration (CLENEX and CLEN) exhibited significant increases in left ventricular internal dimension at the end of both diastole and systole, indicating cardiac dilation.
- Increased thickness was also observed in the interventricular septal wall and the left ventricular posterior wall.
- Noticeable enlargements in aortic root dimensions were observed in the CLENEX and CLEN groups, hinting at a heightened risk of aortic rupture.
Conclusion
- From the gathered data, the study concludes that chronic administration of clenbuterol has negative implications on heart function.
- The enlarged cardiac structures and increased aortic root dimensions might lead to severe cardiac complications, possibly including aortic rupture and heart failure.
Cite This Article
APA
Sleeper MM, Kearns CF, McKeever KH.
(2002).
Chronic clenbuterol administration negatively alters cardiac function.
Med Sci Sports Exerc, 34(4), 643-650.
https://doi.org/10.1097/00005768-200204000-00013 Publication
Researcher Affiliations
- University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA, USA.
MeSH Terms
- Adrenergic beta-Agonists / administration & dosage
- Adrenergic beta-Agonists / adverse effects
- Animals
- Aorta, Thoracic / diagnostic imaging
- Aorta, Thoracic / pathology
- Clenbuterol / administration & dosage
- Clenbuterol / adverse effects
- Echocardiography, Stress
- Female
- Heart / drug effects
- Heart / physiopathology
- Heart Ventricles / drug effects
- Heart Ventricles / pathology
- Horses
- Myocardium / pathology
- Physical Conditioning, Animal / physiology
- Rest / physiology
- Ventricular Remodeling
Citations
This article has been cited 8 times.- Jessen S, Baasch-Skytte T, Onslev J, Eibye K, Backer V, Bangsbo J, Hostrup M. Muscle hypertrophic effect of inhaled beta(2) -agonist is associated with augmented insulin-stimulated whole-body glucose disposal in young men.. J Physiol 2022 May;600(10):2345-2357.
- Li C, Adhikari BK, Gao L, Zhang S, Liu Q, Wang Y, Sun J. Performance-Enhancing Drugs Abuse Caused Cardiomyopathy and Acute Hepatic Injury in a Young Bodybuilder.. Am J Mens Health 2018 Sep;12(5):1700-1704.
- Talan MI, Ahmet I, Xiao RP, Lakatta EG. β₂ AR agonists in treatment of chronic heart failure: long path to translation.. J Mol Cell Cardiol 2011 Oct;51(4):529-33.
- Pearson W, Charch A, Brewer D, Clarke AF. Pilot study investigating the ability of an herbal composite to alleviate clinical signs of respiratory dysfunction in horses with recurrent airway obstruction.. Can J Vet Res 2007 Apr;71(2):145-51.
- Ramos BP, Colgan LA, Nou E, Arnsten AF. Beta2 adrenergic agonist, clenbuterol, enhances working memory performance in aging animals.. Neurobiol Aging 2008 Jul;29(7):1060-9.
- Burniston JG, Clark WA, Tan LB, Goldspink DF. Dose-dependent separation of the hypertrophic and myotoxic effects of the beta(2)-adrenergic receptor agonist clenbuterol in rat striated muscles.. Muscle Nerve 2006 May;33(5):655-63.
- Burniston JG, Chester N, Clark WA, Tan LB, Goldspink DF. Dose-dependent apoptotic and necrotic myocyte death induced by the beta2-adrenergic receptor agonist, clenbuterol.. Muscle Nerve 2005 Dec;32(6):767-74.
- Plant DR, Kearns CF, McKeever KH, Lynch GS. Therapeutic clenbuterol treatment does not alter Ca2+ sensitivity of permeabilized fast muscle fibres from exercise trained or untrained horses.. J Muscle Res Cell Motil 2003;24(7):471-6.
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