The endurance training program was identical to that utilized in a previous study in our laboratory.6 This exercise program was performed on a treadmill that was designed for human use (Runner, Brazil) and modified for use by rats. Two days before the surgical procedures, the rats were subjected to a maximal exercise test (MET). The test consisted of graded exercise on the treadmill during which the speed was incremented from
5 m/min by 5 m/min every 3 min to the maximum intensity attained by each rat. This training program consisted of running on the treadmill for 20 min on the first day, and this period was progressively increased every day up to 50 min on the fifth day and 60 min in the next 4 weeks. Each training session included a warm-up period of 5 min at 30% of the maximum speed reached in the MET