[Short-period oscillations of isotopic carbon in CO2 from expired air in different human functional states].

The examination of diurnal variations in carbon isotope composition of CO2 under different hormonal-metabolic states in man revealed short-period inphase oscillations with a period of about 2-3 h. The oscillations occur throughout 24 h and their period is little dependent on the functional state of the organism. In endocrine pathologies, substantial differences in oscillation amplitude are observed. The relationship between the variations in carbon isotope composition of CO2 of expired air and energy exchange in cells of insulin-dependent tissues of the organism is substantiated.