FAST-TWITCH MUSCLE FIBERS HYPERTROPHY IS HAMPERED BY ANTIOXIDANT SUPPLEMENTATION DURING ATROPHY REHABILITATION IN RATS.

The role of antioxidant supplementation on muscle recovery after disuse is unknown. The aim was to investigate the effect of Vitamin C and E supplementation on muscle recovery after hindlimb suspension. Twenty-two Wistar rats were allocated into 4 groups: exercise with supplementation (VIT, n = 5); exercise with placebo (PLA, n = 5); hindlimb suspension (SUSP, n = 6), and control (CON, n = 6). All groups, except for CON, were submitted to a hindlimb suspension protocol for 10 days. Then, VIT and PLA underwent 10 days of a rehabilitation protocol consisting of exercise on a treadmill. VIT received vitamin C (250 mg/kg/day) and E (360 mg/kg) during rehabilitation. Samples of soleus and tibialis anterior were prepared for cross-sectional area (CSA) and biochemical analysis. Both VIT (1265.6 m μ ², 95% CI: 1234.6–1290.3) and PLA (1280.9 m μ ², 95% CI: 1296.4–1354.9) presented higher CSA of the soleus in relation to CON (816.66 m μ ², 95% CI: 866.3–904.0, P <  0.05) with no difference between them. Both VIT (1276.9 m μ ², 95% CI: 1378.7–1484.6) and PLA (1573.3 m μ ², 95% CI: 1553.9–1651.5) presented higher tibialis anterior CSA in relation to CON (1041.56 m μ ², 95% CI: 1119.1–1185.2, P <  0.05). In this muscle, CSA of PLA was higher than VIT (P <  0.05). Vitamin's supplementation attenuated tibialis anterior hypertrophy following the rehabilitation protocol. [ABSTRACT FROM AUTHOR]