Endurance training-induced cardiac remodeling in a guinea pig athlete's heart model

Besides the health benefits of regular exercise, high-level training - above an optimal level -may have adverse effects. In this study, we investigated the effects of long-term vigorous training and its potentially detrimental structural-functional changes in a small animal athlete's heart mode...

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Bibliographic Details
Main Authors: Topal Leila
Polyák Alexandra Júlia
Tóth Noémi
Ágoston Gergely
Bencsik Péter
Kohajda Zsófia
Prorok János
Déri Szilvia
Nagy Norbert
Jost Norbert László
Virág László
Farkas Attila
Varró András
Baczkó István
Format: Article
Published: 2022
Series:CANADIAN JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY 100 No. 10
Subjects:
doi:10.1139/cjpp-2022-0073

mtmt:32991465
Online Access:http://publicatio.bibl.u-szeged.hu/25313
Description
Summary:Besides the health benefits of regular exercise, high-level training - above an optimal level -may have adverse effects. In this study, we investigated the effects of long-term vigorous training and its potentially detrimental structural-functional changes in a small animal athlete's heart model. Thirty-eight 4-month-old male guinea pigs were randomised into sedentary and exercised groups. The latter underwent a 15-week-long endurance-training program. To investigate the effects of the intense long-term exercise, in vivo (echocardiography, electrocardiography), ex vivo and in vitro (histopathology, patch-clamp) measurements were performed. Following the training protocol, the exercised animals exhibited structural left ventricular enlargement and significantly higher degree of myocardial fibrosis. Furthermore, resting bradycardia accompanied by elevated heart rate variability occurred, representing increased parasympathetic activity in the exercised hearts. The observed prolonged QTc intervals and increased repolarization variability parameters may raise the risk of electrical instability in exercised animals. Complex arrhythmias did not occur in either group and there were no differences between the groups in ex vivo or in cellular electrophysiological experiments. Accordingly, the high parasympathetic activity may promote impaired repolarization in conscious exercised animals. The detected structural-functional changes share similarities with the human athlete's heart, therefore, this model might be useful for investigations on cardiac remodeling.
Physical Description:993-1004
ISSN:0008-4212