[Gas exchange and transport in the body during acute anemia correction by modified hemoglobin solution or attributed to inhalation of a hyperoxic gas mixture]. / Gazoobmen i transport gazov v organizme pri korrektsii ostroi anemii rastvorom modifitsirovannogo gemoglobina ili za schet dykhaniia giperoksicheskoi gazovoi smes'iu.

Total and specific characteristics of changes in gas exchange and transport, tissue oxygenation, circulatory and respiratory compensatory reactions were examined in three groups of necrotized Wistar rats during acute anemia correction by two methods, replacement of red cell mass loss with modified hemoglobin solution (Hb 4.4 g/dl, P50 21.5 mm Hg) or respiration with a hyperoxic mixture (90% of oxygen in nitrogen). In control animals anemia was induced with blood replacement with 6% albumin solution during atmospheric air inhalation. The studied methods for anemia correction were found to increase oxygen levels in arterial blood and similarly effective in total gas exchange maintenance; however the mechanisms of oxygen delivery from arterial blood to tissues being quite different, use of hemoglobin solution was associated with a number of adverse features in gas transport system, acid-base balance, reactions of minute volumes of circulation and respiration which were caused by changed oxygen-binding characteristics of modified hemoglobin and the presence of high concentrations of free hemoglobin in blood plasma.

[Characteristics of the distribution and reference values of 12 biochemical indices of the blood serum]. / Osobennosti raspredeleniia i referentnye granitsy 12 biokhimicheskikh pokazatelei syvorotki krovi.

Twelve blood serum parameters: sodium, potassium, chlorine, total protein, cholesterol, glucose, urea nitrogen, creatinine, bilirubin, alkaline phosphatase, alanine and aspartate aminotransferases activities were measured in 488 normal subjects (male), residents of Leningrad, by the Technicon (USA) microanalyzer. Relationships between the estimated reference values and the distribution patterns of the referent blood parameters (variability, symmetric pattern) were analyzed. The authors compare the reference values of the Leningrad population with those obtained by this microanalyzer in the USA.

[Oxygen supply of the liver following hemodilution with an albumin solution]. / Kislorodnoe snabzhenie pecheni pri gemodiliutsii rastvorom ablumina.

Wistar rats were subjected to gradual blood replacement with albumin solution (hemodilution). Variation of oxygen tension (pO2) in the liver as well as parameters of oxygen transport in arterial and portal blood were measured. Tissue pO2 showed some increase after hematocrit dropped to 35-40% whereas tissue pO2 rapidly decreased after further dropping of the hematocrit. Hemoglobin saturation with oxygen grew in portal vein under moderate hemodilution. Left shift of the oxyhemoglobin dissociation curve and increase of the portal pO2 occurred simultaneously. These changes in portal blood could be a cause of the liver tissue pO2 increase in early steps of the hemodilution.

[Changes in oxygen tension in the cerebral cortex during hemodilution]. / Izmeneniia napriazheniia kisloroda v kore bol'shogo mozga pri gemodiliutsii.

Wistar rats were subjected to gradual blood replacement with 7% albumin (hemodilution). Hematocrit and mean arterial pressure were measured periodically. Polarographic platinum microelectrodes with a tip 3-8 microns in diameter were used to study variation of oxygen tension (pO2) in the brain cortex during hemodilution. Some areas showed a significant decrease in the brain pO2 after hematocrit dropped to 30%. In animals with an initially low pO2 (13.1 +/- 1.7 mm Hg), this parameter decreased more slowly than in rats with a higher basic pO2 (24.5 +/- 1.7 mm Hg).

[Physiological mechanisms for maintaining the body's energy requirements during reduced blood hemoglobin levels]. / O fiziologicheskikh mekhanizmakh obespecheniia énergeticheskikh potrebnostei organizma pri umen'shenii kontsentratsii gemoglobina v krovi.

Energy expenditure and O2 consumption, the tidal volume of cardiac output (Q) and the respiration (VE), the arterio-venous difference in O2 content, the arterial and venous blood gases, and the survival of animals in graded decrease of the hemoglobin concentration in the vascular bed (hemodilution) were studied in anesthetized Wistar rats as well as the values of oxygen available in the brain tissue. The animals were shown to maintain the initial level of energy expenditure by means of the Q increase up to reducing the hemoglobin concentration from 16.2 g/dl to 4.9 g/dl (hematocrit 12.9%). The elements of oxygen insufficiency, however, as measured by the Q and VE responses as well as by changes in oxygen available in mixed venous blood and in brain tissue, become evident yet in early stages of the hemodilution.