[Nitric oxide synthesis during different stages of competition period in well-trained athletes].

Abstract

In the study 26 trained male and female sportsmen aged 18-20 years old have been investigated. The sex differences in the degree of the nitric oxide synthesis in various stages of their training and competitive activities were shown. In female sportsmen, at the time of maximal functional capacity and adaptation (beginning of the competition period), a multi-path nonoxidizing arginine metabolism by arginase was prevailed over the oxidative degradation of L-arginine by cNOS. In females, during dezadaptation period (in the middle and the end of competition), the required level of NO synthesis is maintained mainly by non-oxidative resynthesis of nitric oxide from its stable metabolites. In males, however, the level of NO synthesis is maintained mainly by an increase in oxidative degradation of L-arginine with the gradual change in activity of different isoforms of NOS (cNOS as well as iNOS).