Nitric Oxide Biomarkers Increase During Exercise-Induced Vasodilation in the Forearm

Abstract

The purpose of the study was to determine if exercise-induced vasodilation was associated with an increase in forearm plasma levels of nitric oxide (NO) biomarkers (NO2- + NO3- and L-citrulline). Twelve healthy subjects (27+/-6 yrs) performed incremental rhythmic forearm exercise with the nondominant hand for 6 min each at 15, 30 and 45% of maximal voluntary contraction (MVC). Forearm blood flow (FBF) was determined in the exercise arm using venous occlusion plethysmography. Blood samples were obtained from the antecubital vein of the exercise and nonexercise arms for the measurement of NO biomarkers. In the exercise arm, FBF increased by a mean of 150%, 335% and 585% above baseline at 15, 30 and 45% of MVC, respectively. (ANOVA, P= 0.0001). Venous plasma NO2- + NO3- levels increased from 24+/-4 micromol/L at baseline, to 29+/-5, 32+/-4 and 3+/-4 micromol/L (ANOVA, P = 0.0001). Venous plasma L-citrulline levels increased from 31+/-5 micromol/L at baseline to 58+/-10, 87+/-7 and 141+/-15 micromol/L (ANOVA, P = 0.0001). There was a linear relationship between FBF and venous plasma NO2- + NO3- (slope= 0.38+/-0.10, P=0.0007) and between L-citrulline, (slope= 5.1 +/-1.3, P = 0.0004). Venous plasma levels of NO2- + NO3- and L-citrulline in the nonexercise arm were unchanged. These results demonstrate that exercise-induced vasodilation in the forearm is associated with forearm plasma levels of NO2- + NO3- and L-citrulline, in vivo markers of NO production.

Acute resistance exercise with blood flow restriction effects on heart rate, double product, oxygen saturation and perceived exertion

“…It is likely that the HI resistance exercise protocol is capable of promoting greater blood mobilization (Copeland et al, 1996) and, consequently, higher amounts of postexercise muscle oxygen in relation to LI training. Consistent with this idea, it is speculated that the HI protocol may have stimulated the increased production of nitric oxide, a known potent vasodilator, because it mobilized a larger volume of blood (Brown et al, 2000). Thus, lower oxygen percentages were observed in the LI and LI+BFR protocols, suggesting that exercise intensity is an important factor influencing the acute responses of oxygen saturation.…”

The Interplay between Oxidative Stress, Exercise, and Pain in Health and Disease: Potential Role of Autonomic Regulation and Epigenetic Mechanisms

“…Additionally, moderate exercise (60% of peak workload) increased oxidative stress in patients suffering from cystic fibrosis but not in healthy volunteers [59]. In conclusion, despite inconsistencies in the literature, most research showed that moderate exercise has the potential to induce oxidative stress and increase total antioxidant status [25,53,[60][61][62].…”

The Effect of Branched-Chain Amino Acids, Citrulline, and Arginine on High-Intensity Interval Performance in Young Swimmers

“…Nitric oxide (NO), a signaling molecule with a wide range of physiological functions, has been suggested to improve exercise performance by enhancing exercise-induced vasodilation [17], increasing the oxygenation status in the working muscles, and improving VO 2 kinetics [18]. Supplementations of arginine or citrulline, both of which are precursors to NO, have been suggested to improve performance in high-intensity exercise [19,20].…”