Efeitos do Treinamento Combinado Resistido-Aeróbio no Ventrículo Esquerdo de Rato Wistar

Abstract

The objective of this work was to determine the effects of combined resistance- aerobic training on the left ventricle (LV) weight, LV wall thickness and LV cavity dimension in rats. One group of rats (n=5), the combined resistance-aerobic group (RA) were submitted to exercise and a sedentary control group (C) (n=5) was included. Rats were trained to climb a 1.1 m vertical (80° incline) ladder with weights tied to their tails, which were progressively augmented. After each resistance training session, the animals were trained to run 1 hour/day on the treadmill. Exercise training was performed 5 times weekly for 8 weeks. After the sacrifice, the myocardium was perfused with glutaralde hyde and the LV was isolated and weighed. Themid-zone of the LV free wall was incised transversely obtaining a ring with a thickness of 0.5 cm, which was included in Epon resin yielding blocksf or performing histological sections transversely to the long axisof the cavity with 0.5 µm thick that weres tained with to luidine blue and used to measure the diameter of the cavity and the thickness of the wall. The results showed that the values of the LV weight was 10.5% larger in the RA group (P< 0.05), compared with the C group, the LV wall thickness was 8% larger in the RA group (P<0.05), than in C group and the LV internal diameter was 4.5% larger in RA group (P <0.05), than in C group. Conclusion: The resistance-aerobic trainingused in this studyinducedthe developmentof aspecific typeof hypertrophyof the LV wall, which combinesthe effects ofaerobic trainingandresistance training. The resistance-aerobic training increases the ventricular cavity while increasing wall thickness.