L-Arginine and Its Methylated Derivatives in the Blood of Athletes

The indices of the system of endogenous regulation of nitric oxide (NO) bioavailability of were compared in the group of athletes and the control group of subjects with a sedentary lifestyle. The concentrations of L -arginine (as a substrate of NO synthase and arginase) and its methylated derivatives monomethylarginine and asymmetric and symmetric dimethylarginines (MMA, ADMA and SDMA) in the blood were measured using high performance liquid chromatography (HPLC) with fluorescent detection. In parallel, some common biochemical blood parameters and the total antioxidant status were evaluated. The concentration of L -arginine in the blood plasma of athletes was 24% higher than the concentration in the control group. The levels of ADMA and SDMA were lower by 39 and 80%, respectively. The MMA level was almost two times higher than that in the control group. The total protein, bilirubin, total cholesterol, and triglyceride levels were significantly lower in athletes compared with the control. Interesting significant correlations were found between L- arginine and urea in the control group and between the Arg-to-ADMA ratio and the antioxidant activity index in the group of athletes.