[HR AND DURATION OF ECG ELEMENTS OF AN ADULT DURING PHYSICAL EXERCISES].

The degree of heart rate (HR) and of duration PP, PT and TP elements electrocardiogram (ECG) before and after physical exercises (PE) depends on their value in the control, in healthy young girls (n = 21), aged 18.1 ± 0.7 years, body weight 56.

[Spectral parameters of heart rate variability in man under the acute normobaric hypoxia conditions].

Spectral parameters (SP) of heart rate variability (HRV) and a duration of cardiointervals (RR) in 14 healthy male volunteers at the age of 23-36 years under the influence of acute normobaric hypoxia by respiratory gas oxygen-nitrogen mixture (9% O2, 25 min) were studied. The 300 cardiocycles at each of six experimental time points by ECG at II standart lead were registered. The parameters before hypoxia were (M ± m): RR (s) 0.

[Effects of acute normobaric hypoxia on free plasma amino acids metabolism in humans].

We demonstrated significant changes in levels of several plasma free amino acids--proline, hydroxyproline, glycine, and phenylalanine--in healthy volunteers in response to severe acute normobaric hypoxia (breathing nitrogen-oxygen mixture with 9% of O2). We assume that demonstrated an increase of free proline, hydroxyproline, and glycine in plasma in the 10th minute of hypoxia was caused by increased collagenolysis due to hypoxic activation of matrix metalloproteinases. Significantly increased levels of free phenylalanine in the 10th and 20th minutes of hypoxia were the consequences of autophagy activation.

[Blood lactate dehydrogenase activity in newborn children].

Arterial and venous blood samples from babies' umbilical cord vessels before lung breath beginning were used to measure arterial-venous difference between lactate dehydrogenase activity, pH and oxygen blood saturation (sO2). Enzyme activity was 735.4 +/- 90.

[Serum glucose level in acute severe hypoxia in human at rest].

Study of the effects of acute normobaric hypoxia was performed on a group of young healthy males (age 19-23, n = 10). Conditions of acute normobaric hypoxia were modeled by using oxygen-nitrogen mixture containing 8% of oxygen as a breath gas. That level of oxygen corresponds with its partial pressure at 7000 meters above sea level.

[Fatty acid of human plasma under the influence of acute strong normobaric hypoxia].

The influence of acute normobaric hypoxia on total pool of human plasma fatty acids was studied in experiment (respiration of hypoxic gas mixture containing 8% of O2, during 25 min). Health status of participants-volunteers and the hypoxia intensity were monitored with a complex of electrophysiological methods: EEC, ECG, measurement of blood pressure, SpO2, evaluation of cardiac output, gas analysis of exhaled air. Using gas chromatography we studied plasma fatty acids total profile (esterificated and non-esterificated) before hypoxia exposure, on 2nd, 5th, 10th, 20th minutes of acute hypoxia and on 5th and 15th minutes of recovery.

[Interrelationships among cardiohaemodynamic parameters in human postnatal ontogenesis].

In one-day old humans and to 20 years of age, the stroke volume (SV) increases from 5.4 +/- 0.4 to 70 +/- 5 ml, the arterial systolic pressure (ASP)--from 60 +/- 5 to 120 +/- 10 mm Hg.

Temperature dependence of H+ transport across erythrocyte membrane of Rana temporaria grass frog in media containing Cl- and SO4(2-).

H+ transport across the erythrocyte membrane was studied in Rana temporaria grass frog. The temperature coefficients and activation energy of H+ transport were calculated in media containing Cl- and SO4(2-). Our results show that kinetic characteristics of H+ transport depend on function of band 3 protein in the erythrocyte membrane.

Relationship between H+ transfer through human erythrocyte membrane and temperature.

The parameters of thermal dependence of H+ transport into human erythrocytes in the presence of furosemide were measured. The relationship between these changes and function of band 3 protein of the erythrocyte membrane is discussed.

[Mechanical work of the left ventricle of the human heart].

By means of the echocardiographic techniques, morphometric and functional parameters of the heart left ventricle (HLV) were studied in male humans aged 20 to 23, in resting and under the effect of a physical load. The total ventricle work was found to be about 1 J, the relative one (per 100 g of the LV mass)--0.6 J.

[Mechanical human heart work in a newborn infant].

The echo- and dopplerography of newborn infants up to 10-day age revealed that their heart work capacity was about 6 Wt, relative capacity--25 Wt/100 g of ventricular mass. These data correspond to those of adult humans. The Frank-Starling mechanism was corroborated.