[Oxygen transport properties of the blood in acute nitrite methemoglobinemia]. / Kislorodtransportnye svoistvia krovi pri ostroi nitritnoi metgemoglobinemii.

Studies showed that a single injection of 5 mg/100 g of sodium nitrite causes the development of marked hemic hypoxia in rats, which is characterized by considerable increase of methemoglobin concentration, reduction of O2 content and O2 tension in arterial blood, sharp fall of the intensity of O2 consumption, decrease of methemoglobin concentration, and increase of the content of 2,3-diphosphoglycerate in the red cells. This is evidence of disturbed blood oxygen-transport function and the development of compensatory mechanisms directed at improving O2 supply to the tissues.

[Compensatory mechanisms regulating oxygen transport and erythropoiesis during an alteration in the erythrocyte composition of the blood in rats]. / Kompensatornye mekhanizmy reguliatsii transporta kisloroda i éritropoéza pri izmenenii éritrotsitarnogo sostava krovi u krys.

The data obtained revealed that the level of 2,3-DPH in erythrocytes and that of erythropoietin in the blood plasma were important compensatory mechanisms for regulation of the oxygen transport and the erythropoiesis in alteration of the blood erythrocyte composition in rats.

[Changes in the oxygen transport properties of the blood of animals after a stay in a high-density normoxic gas environment]. / Izmeneniia kislorodtransportnykh svoistv krovi u zhivotnykh posle prebyvaniia v normoksicheskoi gazovoi srede povyshennoi plotnosti.

For 24 hrs after exposure of rats to normoxic nitrogen-oxygen mixture of high density, concentration of hemoglobin, the hematocrit value, the number of erythrocytes, the contents of 2,3-DPG in erythrocytes, and the plasma erythropoietic activity were increased. Within 72 hrs after the exposure the above parameters returned to normal. The data obtained suggest that rats exposed to normoxic nitrogen-oxygen mixture of high density develop compensatory changes of the blood O2-properties and erythropoiesis as the result of hypoxia and oriented to improvement of tissue oxygen supply.

[Oxygen transport properties of blood in the presence of excess oxygen in the body]. / Kislorodtransportnye svoistva krovi pri izbytke kisloroda v organizme.

Concentration of 2,3-DPC was decreased in erythrocytes and the plasma erythropoietic activity was reduced in rats in hyperoxia as well as in rats with the post-transfusional and posthypoxic polycythemia. The data obtained suggest changes of both the oxygen transport properties of the blood and the erythropoiesis in order to limit the oxygen supply of tissues under conditions of excessive oxygen in the organism.

[Oxygen transport properties of the blood in experimental renal hypertension in the rat]. / Kislorodtransportnye svoistva krovi pri éksperimental'noi pochechnoi gipertenzii u krys.

In rats with artificial renal hypertension, the amount of erythrocytes in the blood was increased in 43% of cases within 2-3 months after surgery. Diverse changes of the blood oxygen-transport properties indicate several mechanisms of the organism adaptation to changes in oxygen regiment in response to the arterial pressure increase due to ischemia of renal tissue: an increase in the blood oxygen capacity; changes of the hemoglobin oxygen-binding properties. The parameters under study, except the arterial pressure, did not differ from the control ones in a number of experimental animals.

[Mechanism of development of erythrocytosis in spontaneous arterial hypertension in rats]. / O mekhanizme razvitiia eritrotsitoza pri spontannoi arterial'noi gipertenzii u krys.

Rats with spontaneous hypertension versus normotensive rats showed the development of erythrocytosis, an intensification of the erythropoietic properties of the blood plasma and an increase of the 2,3-DPG concentration in the red blood cells. An enhanced production of erythropoietin, a humoral stimulator of erythropoiesis, seems to be one of the causes of the erythrocytosis development in spontaneously hypertensive rats. An increase in the 2,3-DPG concentration in the erythrocytes is an important physiological mechanism ensuring the appropriate oxygen supply to tissues.

[Indices of the oxygen-transport properties of the blood and of erythropoiesis in rats after being in a nitrogen-oxygen environment under elevated pressure]. / Pokazateli kislorodtransportnykh svoistv krovi i éritropoéza u krys posle prebyvaniia v azotno-kislorodnoi srede pod povyshennym davleniem.

Rats staying for a long time in nitrogen-oxygen mixture under high pressure develop changes in the blood oxygen-transporting properties and in erythropoiesis indicating state of hypoxia and tending to improve oxygen supply in tissues. Remote consequences of the hyperbaria tell even within 3 days after its cessation.

[Plasma erythropoiesis inhibitors in humans during hyperbaric hyperoxia]. / Ingibitory éritropoéza v plazme krovi u cheloveka pri giperbaricheskoi giperoksii.

Before exposure of man to hyperbaric hyperoxia the blood plasma possessed marked erythropoietic activity. Erythropoietins disappeared completely and erythropoiesis inhibitors appeared in the plasma of persons untrained to hyperbaric hyperoxia after a 24-hour exposure to hyperoxic conditions (25% of oxygen in the inhaled air) in the high pressure chamber corresponding to the depth of 63 metres. A reduction of the peripheral red blood indices was observed by that time.

[Effect of oxygen metabolism in kidney tissue on the development of plasma erythropoietic properties]. / Vliianie obmena kisloroda v pochechnoi tkani na formirovanie éritropoéticheskikh svoistv plazmy.

The oxygen metabolism (pO2, the constant of the oxygen rate consumption, the coefficient of the oxygen distribution), the activity of oxid-reduced and hydrolytic enzymes, the blood supply of the kidney cortex and medulla, were recorded. These data were compared with the erythropoietin activity of plasma in the rats with phenylhydrazine anemia and posttransfusion polycytemia. An obvious reverse interrelationship existed between plasma erythropoietin activity and value of pO2 and blood supply of the cortex. The activity of the above enzymes was practically unchanged. The data obtained suggest that erythropoietin is formed in the cortex of the kidney and its production is controlled by the degree of oxygen supply of the kidney tissue.

[Erythropoietic activity of human blood following exposure to hyperbaric hyperoxygenation]. / Eritropoéticheskaia aktivnost' krovi u cheloveka posle prebyvaniia v usloviiakh giperbaricheskoi giperoksii

Before exposure of man to hyperoxia the blood plasma posessed erythropoietic activity, but 18 to 20 hours after exposure to compressed air condition in the high pressure chamber corresponding to the depth of 100 metres there proved to be a marked fall of the erythropoietic activity. No statistically significant shifts were revealed in the peripheral blood indices by that time.

[Erythropoietic function of the kidneys under conditions of abnormally high oxygen pressure]. / Eritropoéticheskaia funktsiia pochek v usloviiakh povyshennogo davleniia kisloroda

Three to five hours after 5-hour exposure of rabbits to high oxygen pressure (2 ata) the erythropoietin proved to disappear from both the arterial and the venous blood plasma of the kidneys. At the same time the blood plasma from the renal vein began to suppress the mitotic activity of erythroblastic cells in the bone marrow culture. These data testify to the fact that under hyperbaric hyperoxia the kidneys secreted the inhibitor of erythropoiesis. No erythropoiesis inhibitor was revealed 24 hours after the hyperoxia.