[Characteristics of arginine metabolism and nitric oxide synthesis in young people during adaptation to physical load in training and competition periods].

A survey of 29 trained and untrained youths in the age of 18-20 years was carried out. It is shown that the optimal level of adaptation of the body to prolonged and intensive physical activity is provided by multi-dominance nonoxidizing arginase metabolism and its oxidative metabolism by constitutively calcium dependent NO-synthase (eNOS and nNOS). Nonoxidizing arginase metabolism results in formation of several important low-molecular bioregulators and antioxidants (urea, polyamines, GABA). Significant reduction of functionality of the trained body at the end of the competitive period and consequently disadaptation correlates with Ca(2+)-independent NO synthesis which does not compensate the organism needs in NO.