Materials Ethical approval All experiments were undertaken according to the norms established by the Brazilian Association for Animal Experimentation (COBEA) and were previously approved by the Ethics Committee in Animal Research of the State University of Maringá (protocol number 084/2009). Animals and obesity induction Sets of 3 female

and 1 male Wistar rats, 70 days old, were mated. After 1 week, the pregnant rats were separated. On the 2nd day of life, the size of the normal litters (NL) was set to 9 pups; while the small litter (SL) size was set to 3 pups. After weaning (21st day), males were selected, and all females were discharged. Young male rats click here from the NL and SL groups were randomly chosen for exercise. Animals received water and a commercial diet (Nuvital®; Curitiba/PR, Brazil) ad libitum. During all protocol stages, the animals were placed in an environmentally controlled room (23 ± 3°C; 12 hour light/dark photocycle (07:00–19:00 h). Exercise training protocol Rats from the NL exercised (NL-EXE) and SL exercised (SL-EXE) groups were trained on an animal treadmill (model ET-2000 Insight®; Ribeirão Preto/SP, Brazil). Three trained groups

were established: exercise beginning after weaning in 21-day-old rats and ending at 90-day-old (EXE21–90); exercise beginning at weaning and stopped at 50-day-old (EXE21–50); and exercise beginning at 60 days old and ending at 90 days old (EXE6060–90). Another group of NL and SL rats did not exercise at all (N-EXE). Running protocols, including MEK inhibitor cancer running speeds and times, were set to induce moderate-intensity exercise training,

promoting a 50-70% total oxygen uptake (VO2max) for each animal, independent of age. The running protocols used have Fenbendazole been described previously [27, 28] with some modifications. The anaerobic threshold of the rats is approximately 20 m.min-1 and was used to delimit the maximal velocity reached in the training program. This protocol was intended to guarantee the same aerobic exercise intensity across all ages as the animals grew. Adaptation period of exercise protocol Exercise sessions lasted 10 min on the first day of the adaptation period, and the rats were run at a velocity of 10 m × min-1. The sessions were increased to 20 min at 12 m × min-1 for the subsequent sessions. The rats in the group exercised from days 21–90 had an adaptation time of two weeks, and the rats in the 21–50 day group and the 60–90 day group had an adaption time of one week, as previously reported [27]. The running sessions were performed in the afternoon. The rats that did not adapt were eliminated. Training period In the EXE21–90 groups, the initial training speed was 12 m × min-1 for 20 min and was increased to 20 m × min-1 for 60 min over ten weeks (Figure 1A).