Cardiac effects of acute exhaustive exercise in a rat model

Attila Oláh, Balázs Tamás Németh, Csaba Mátyás, Eszter Mária Horváth, László Hidi, Ede Birtalan, Dalma Kellermayer, Mihály Ruppert, Gergo Merkely, Gábor Szabó, Béla Merkely, Tamás Radovits

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Background: The role of physical exercise in the prevention and treatment of cardiovascular diseases has been well described, however, elevations in cardionecrotic biomarkers after prolonged exercise (i.e. ultramarathon running) were observed. We aimed at understanding the biochemical, molecular biological, structural and functional alterations in the heart after exhaustive exercise in a rat model. Methods: Rats of the exercise group were forced to swim for 3 h with 5% bodyweight (workload) attached to the tail, control rats were taken into the water for 5 min. After a 2-hour recovery period we performed left ventricular (LV) pressure-volume analysis to investigate LV function and mechanoenergetics. Additionally, blood and myocardium samples were harvested for biochemical and histological examinations. Gene expression changes were detected by qRT-PCR. Results: When compared to controls, elevated plasma levels of cardiac troponin T and creatine kinase were detected after exhaustive exercise. Histological analysis showed sporadic fragmentation of myocardial structure and leukocyte infiltration in the exercised group. We observed increased end-systolic volume, decreased ejection fraction, impaired contractility (preload recruitable stroke work) and mechanoenergetics (ventriculoarterial coupling, mechanical efficiency) of LV after exercise. Myocardial expression of major antioxidant enzymes was increased alongwith increasedmyocardial nitro-oxidative stress. Bax/Bcl-2 ratio and TUNEL staining showed enhanced apoptotic signaling. Exhaustive exercise also resulted in the dysregulation of the matrix metalloproteinase system. Conclusions: Excessive physical activity has an adverse effect on the heart. The observed functional impairment is associated with increased nitro-oxidative stress, enhanced apoptotic signaling and dysregulation of the matrix metalloproteinase system after exhaustive exercise.

Original languageEnglish
Pages (from-to)258-266
Number of pages9
JournalInternational Journal of Cardiology
Volume182
Issue numberC
DOIs
Publication statusPublished - Jan 1 2015

Keywords

  • Cardiac function
  • Cardiac mechanoenergetics
  • Exhaustive exercise
  • Gene expression
  • Oxidative stress
  • Pressure-volume analysis

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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  • Cite this

    Oláh, A., Németh, B. T., Mátyás, C., Horváth, E. M., Hidi, L., Birtalan, E., Kellermayer, D., Ruppert, M., Merkely, G., Szabó, G., Merkely, B., & Radovits, T. (2015). Cardiac effects of acute exhaustive exercise in a rat model. International Journal of Cardiology, 182(C), 258-266. https://doi.org/10.1016/j.ijcard.2014.12.045