title: Moderate exercise training provides left ventricular tolerance to acute pressure overload.
abstract: The present study evaluated the impact of moderate exercise training on the cardiac tolerance to acute pressure overload. Male Wistar rats were randomly submitted to exercise training or sedentary lifestyle for 14 wk. At the end of this period, the animals were anaesthetized, mechanically ventilated, and submitted to hemodynamic evaluation with biventricular tip pressure manometers. Acute pressure overload was induced by banding the descending aorta to induce a 60% increase of peak systolic left ventricular pressure during 120 min. This resulted in the following experimental groups: 1) sedentary without banding (SED + Sham), 2) sedentary with banding (SED + Band), and 3) exercise trained with banding (EX + Band). In response to aortic banding, SED + Band animals could not sustain the 60% increase of peak systolic pressure for 120 min, even with additional narrowing of the banding. This was accompanied by a reduction of dP/dt(max) and dP/dt(min) and a prolongation of the time constant tau, indicating impaired systolic and diastolic function. This impairment was not observed in EX + Band (P < 0.05 vs. SED + Band). Additionally, compared with SED + Band, EX + Band presented less myocardial damage, exhibited attenuated protein expression of active caspase-3 and NF-κB (P < 0.016), and showed less protein carbonylation and nitration (P < 0.05). These findings support our hypothesis that exercise training has a protective role in the modulation of the early cardiac response to pressure overload.
authors.affiliation: Faculty of Medicine, Department of Physiology, Department of Sport Biology, Research Center in Physical Activity and Health, University of Porto, Porto, Portugal. danielmgon@gmail.com
authors.forename: Daniel
authors.initials: D
authors.lastname: Moreira-Gonçalves
authors.forename: Tiago
authors.initials: T
authors.lastname: Henriques-Coelho
authors.forename: Hélder
authors.initials: H
authors.lastname: Fonseca
authors.forename: Rita Maria
authors.initials: RM
authors.lastname: Ferreira
authors.forename: Francisco
authors.initials: F
authors.lastname: Amado
authors.forename: Adelino
authors.initials: A
authors.lastname: Leite-Moreira
authors.forename: José Alberto
authors.initials: JA
authors.lastname: Duarte
mesh_terms: D000818:Animals; D053148:Caspase 3 / Q000378:metabolism; D006439:Hemodynamics / Q000502:physiology; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology*; D050050:Protein Carbonylation / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D057185:Sedentary Behavior; D016277:Ventricular Function, Left / Q000502:physiology*
chemical_list: D053148:Caspase 3