Prior study of our group shown that previous aerobic exercise training improved the damage caused by diabetes mellitus on renal and cardiovascular system. Resistance exercise training, also known as strength training, is traditionally performed to gain muscle mass; however, it is not clear whether this type of exercise modulates renal system. Additionally, it is also unknown whether previous resistance exercise training can potentially influence the kidney and skeletal muscle. Wistar rats were submitted to resistance exercise training in an apparatus developed especially to this type of exercise (8 - 12 climbs/day, 5 days/week, 12 weeks). Previous resistance exercise trained group (PTD) performed for 4 weeks before the establishment of the disease and after this period they were followed by 8 weeks of resistance exercise training. Additional trained groups such as trained diabetic (TD) and trained control (TC) groups were followed by 8 weeks of resistance exercise training. Control groups were also followed (control - C, diabetes - D). We have found that PTD suppressed abnormalities linked to renal system such as, water consumption and amount of urine PTD=71mL vs. DT=127mL vs. D=138mL (measured during metabolic cage period), as well as attenuated proteinuria and kidney weight. Regarding to skeletal muscle, PTD group had increased muscle weight (extensor digitorium longus - EDL; C=192mg, D=116mg, TD=106mg and PTD=126mg; Tibialis anterior, C=780mg, D=496mg, DT=450mg and PTD=535mg); we also found a great muscle force level in the PTD group (C=573g, CT=1037, D=414g, TD=737g and PTD=825g), suggesting a protective effect of previous exercise in this group. PTEN was suppressed in PTD group and Akt and 4EBP1 (upstream and downstream of mTOR) were activated in PTD group, measured by western blot. These data suggest that, resistance exercise performed prior the establishment of the diabetes mellitus can protect kidney from diabetic nephropathy and skeletal muscle from atrophy. The mechanisms by which kidney and skeletal muscle have been improved are linked to mTOR signaling pathway. Further studies will be performed to confirm the potential involvement of this signaling pathway.
Support: FAPESP, CAPES, CNPq.