Swimming Physical Training in Rats: Cardiovascular Adaptation to Exercise Training Protocols at Different Intensities

摘要

Guerreiro LF, Pereira AA, Martins CN, Wally C, Gon?alves CAN. Swimming Physical Training in Rats: Cardiovascular Adaptation to Exercise Training Protocols at Different Intensities. JEPonline 2015; 18(1):1-12. There have been many studies of physical exercise in laboratory animal models. However, these studies are limited by their experimental protocols. The aim of the present study was to develop physical training protocols of low, moderate, and high intensity and to compare the cardiovascular acclimation of Wistar rats to these protocols. Forty male rats 60 days old at the beginning of the experiment and weighing 310 ± 10 g were divided into four groups (n=10): control, low intensity (LI), moderate intensity (MI), and intermittent high intensity (HI). The training was divided into an acclimation phase and a maintenance phase and took place 5 times a week over 16 wks. After the training, the animals were euthanized. Creatine kinase and heart morphometry analyses were conducted. Lactate values were 4.0 ± 0.5 mmol·L-1 for LI, 5.5 ± 0.4 mmol·L-1 for MI, and 9.2 ± 1.0 mmol·L-1 for HI. Heart rate was significantly reduced in the LI (339 ± 20 beats·min-1 ) and MI (344 ± 20 beats·min-1 ). Morphometric analyses showed that the thickness of the free wall of the left ventricle was greater in the HI group (2.233 ± 0.29 mm) (P≤0.05). The thickness of the interventricular septum was greater in the HI group (2.158 ± 0.71 mm) and the area of the left ventricle chamber significantly greater in the MI group (25.657 ± 3.6 mm2 ) (P≤0.05). Our results show that these protocols induce different metabolic pathways and promote distinct adaptations in the cardiovascular system to the type of physical training experienced.