[The tissue oxygen partial pressure in organs of hens in the second half of embryogenesis and in the first days after hatching].

The aim of the study was measure the development chick tissue partial pressure of oxygen (pO2) in the brain cerebral hemispheres, liver, M. pectoralis, M. gastrocnemius, and to estimate the correlation of this index with our previously measured values (laser-Doppler flowmetry) volume blood flow (BF) in these organs.

[Rat heat structural and functional characteristics and gas exchange parameters after experimental myocardial infarction].

Rat heart structural and functional changes and gas exchange parameters were investigated in six months after experimental myocardial infarction. Left ventricular end-systolic and end-diastolic dimensions in rats with chronic heart failure were 78 and 30% higher than in control respectively. Left ventricle cavity volume in systole and diastole were 5 and 2 times increased respectively.

[Changes of gas exchange parameters and of functional-biochemical properties of erythrocytes in dynamics of experimental anemia in rats].

In experiments on Wistar male rats, on a specially constructed computer installation, O2 consumption by the animals in comparison with changes of hematological, biochemical, and rheological blood properties is studied after anemization--acute bloodletting (12-15% of the total blood mass). An increase of the O2 consumption by the organism and tissues by 18-28% has been revealed for the first 7 days after the bloodletting, in spite of a pronounced decrease of hematocrit, and of the amount of erythrocytes and hemoglobin in peripheral blood by 20-25% of the initial level. There was a 5-10-fold increase of the content of immature erythrocyte forms--reticulocytes and a progressive rise of cell acidic resistance, which is characteristic of young erythrocyte forms.

[The dynamics of milk secretion in white mice and its consumption by progeny].

Only about 72 per cent of the litter manifested milk ingestion during every next nursing in white mice. The correlation between the dynamics of the milk ejection from the mammary gland and individual real milk intake by the litter, is discussed.

[Changes in the water-salt composition of alveolar and ductal milk in the white mouse when accumulated in the mammary gland].

The ion and water contents revealed a 25-41% lower Na level in the duct than in alveolar secret in lactating albino mice through 1 to 7 and 24th hour of suckling. The data obtained suggests dynamic properties of alveolar and duct epithelium in mice.

[The dynamics of the transepithelial transport of sodium, potassium and water in the mammary gland of the white mouse].

In lactating albino mice, the transepithelial mammary transport of Na+, K+ and water was studied during normal and changed intervals between suckles. The formation of ion and water contents of the mice milk usually occurs in 2 stages N first, all Na+, 1/4 K+ and 1/3 water contents in ready milk enter the secret of mammary gland; second, the Na+ in milk is stopped and net flow of K+ and water is 3- and 2-fold higher than during first stage.

[Fluctuations in local blood flow and oxygen tension in the alveolar complexes of the mammary gland in the course of the secretory cycle].

In lactating albino mice, an interrelationship was found between rhythmic changes of the blood flow intensity and oxygen supply of secretory cells in all the alveoles during secretory cycle. The maximal value of the local blood flow (134 +/- 30 ml/100 g.min) and the minimal O2 tension level (27.

[Patterns of the redistribution of sodium, potassium and water in the tissues of lactating white mice].

The Na+ concentration on the blood plasma of lactating mice increased by 22%. The muscle ion and water contents were unchanged in lactation whereas K+ level was increased by 15% in the red cells, the Na+ concentration - by 23% in mammary alveolar tissue, K+ - 2.5 times and water - 1.

[Patterns of redistribution of calcium and magnesium in the tissues of lactating white mice].

The Ca2+ and Mg2+ contents in the blood, milk and tissues involved in lactation, were studied in lactating and non-lactating albino mice. The Ca2+ concentration in the blood plasma of lactating mice was raised by 25%, and Mg2+--by 78%. The tissue concentrations of these ions did not change during lactation in muscles.

[Blood supply and oxygen supply of localized portions of the mammary glands].

The quantitative analysis of the circulation system providing O2 transport to the mammary tissues in 34 non-lactating and 21 lactating albino mice SHR revealed that the average values of O2 tension in the alveolar complexes (43.3 +/- 14.4 torr) were 1.

[Dynamics of blood circulation and oxygen consumption in mammary glands].

In lactating albino mice, the blood flow rate and oxygen consumption in mammary tissues varied with a period of 45--50 min. The maximal values were reached at the initial stage of the secretory cycle: oxygen consumption 9.7 +/- 2.

[Distribution of oxygen tension in breast tissues].

Using a mathematical model which describes the O2, transport in the alveolar cell of the mammary gland, the distribution of pO2 levels during two stages of the secretory cycle, was calculated. At the initial stage, the typical feature of which is the increased blood flow and O2 consumption, pO2 in the secretory tissue varied from 3 to 30 torr (average 9.9 torr).