L-Arginine Supplementation and Resistance Training Promotes Increase of Maximum Strength and Protection from DNA Damage in Rats

Abstract

L-arginine (Arg) is a precursor of several substances with remarkable physiological functions, such as nitric oxide (NO) and the amino acid creatine. Arg supplementation has been associated with increased strength in high-intensity exercise. However, there is no clear evidence of association of supplementation with Resistance Training (RT) on their antioxidant and ergogenic effects, specifically on their genotoxic protection. Therefore, we evaluated the effect of supplementation of Arg associated with RT 8 weeks about gaining maximum strength and DNA damage in rats. Ten Wistar rats (220-270g, 90 days old) were randomly divided into 3 groups: sedentary (SED, n = 4), Resistance Training (RT, n = 2) and Resistance Training + L-Arginine (RT+Arg, n = 4). Trained rats were submitted to the protocol of RT in a squat apparatus adapted for rats (4 sets of 10-12 reps with 90s interval, 4 times/week, 65-75% of One Maximum Repetition (1MR) for 8 weeks). The supplemented group received Arg (500mg/kg) daily for 8 weeks. After 8 weeks, whole blood was collected from animals to perform the comet assay. It was used CASP software (CASPLabs®) for quantification of DNA damage. To quantify the maximum strength the 1MR test was performed at baseline and after the RT protocol. For comparisons among groups it was performed One- way ANOVA followed by post hoc test of Student-Newman-Keuls. For associations, it was used the Pearson correlation test. We considered the level of significance of 5%.The RT was able to protect DNA damage in rats. However, the association with Arg supplementation was able to promote greater genotoxic protection, compared to sedentary rats. These results indicate remarkable ergogenic action and genotoxic protection of Arg supplementation in association with RT.