A 6-week training program increased muscle antioxidant system in elderly diabetic fatty rats

BACKGROUND It is widely accepted that oxidative stress is associated with the physiopathology of type 2 diabetes mellitus. In fact, it has been pointed out as a therapeutic target in T2DM. Fortunately, several papers have reported that long-term training programs improved the antioxidant system in young and adult diabetic rats. Accordingly, this study was designed to assess the influence of a shorter training program in elderly diabetic fatty rats. MATERIAL/METHODS Study subjects were 24 male homozygous Zucker diabetic fatty rats (Gmi, fa/fa) aged 18 weeks with an average weight of 370-450 g. After a 2-week period of environmental adaptation, animals were randomly distributed into the Exercised Group (n=12) that performed a 6-week swimming training protocol and the Sedentary Group (n=12). Animals were sacrificed under anesthesia 24 h after the last exercise session. Serum metabolic profile was determined. Total antioxidant status (TAS), MnSOD expression, glutathione status and ROS generation were assayed in gastrocnemius muscle. RESULTS When compared with controls, exercised rats significantly improved their metabolic profile. Total antioxidant status (0.19±0.002 vs. 0.13±0.002 µg/mg protein; p<0.001) and MnSOD expression (8471±90 vs. 6258±102 U/µg protein; p=0.003) were also increased in exercised rats. CONCLUSIONS A 6-week swimming training program improved the antioxidant system in elderly fatty diabetic rats. Fortunately, this improvement was enough to reduce oxidative damage, expressed as protein oxidation. A major finding of this study was that our training protocol lasted just 6 weeks, in contrast to longer protocols previously published.