In the present study, we tested the hypothesis that different types of exercise training could lead to different changes in the natriuretic peptides system. We thought that even the swimming training, if chronically realized, could alter the ANP synthesis, secretion and bioavailability in the circulation. To compare the effect of both training modalities, we maintained both exercises at similar intensities by using the intensity of the maximal lactate steady state [11] and [33] to induce adaptations from this website predominantly aerobic activities. The procedures were carried out in compliance with the guidelines for the ethical use of animals in scientific
research as stated by the Federation of the Brazilian Society of Experimental Biology and were approved by the Ethics Committee for Animal Use of
the Federal University of Espírito Santo. The experiments were conducted on 21 spontaneously hypertensive male rats obtained from the Institute of Biomedical Sciences, University of São Paulo (270–300 g; 14 weeks old). The rats were housed with controlled temperature (22 °C), humidity (40%) and light cycles (12-h light/dark), had free access to tap water and were fed standard rat chow (Purina Labina, SP-Brazil) ad libitum. The animals were randomly divided into three groups: sedentary (SD, n = 8), run trained (RT, n = 7) and swim trained (ST, n = 6). learn more The sedentary rats were handled five days/week to become accustomed to the experimental protocols. Swimming training was performed in an apparatus adapted for rats that contained warm water (30–32 °C) and was kept at a depth of 50 cm. The training consisted of swimming sessions five days/week G protein-coupled receptor kinase for 60 min for 8
weeks. The swimming time on the 1st day was 20 min, which was increased daily by 10 min until it reached 60 min on the 5th day. From the second week onwards, the exercise duration was kept constant and the rats were worn caudal dumbbells that weighed 2% of their body weight. The caudal weight was gradually increased until it was 5% on the 6th week and was thereafter kept constant [11], [12], [17] and [21]. All of the rats were weighed weekly to adjust the weight of the dumbbells. The running training was performed on a motorized treadmill (Insight, São Paulo, Brazil) 5 days/week for 8 weeks, with the speed and duration progressively increased. The rats began training at 15 m/min for 20 min/day. The speed was gradually increased such that by the end of the 1st week, the animals ran at 15 m/min for 60 min/day. Thereafter, the duration was maintained but the speed was gradually increased. By the 6th week, the rats ran at 24 m/min for 60 min/day [33], and this exercise program was maintained until the end of the study.