Biomedical subjects

V V Zinchuk

Publications and source records attributed to V V Zinchuk.

26 records · Page 2Linked to original sources

PubMedDate not supplied

[Erythrocyte deformability: physiological aspects].

Analysis of published and author's data on the physiological role of deformability of erythrocytes, general mechanisms of modifications and disturbances, assessment methods, and the role of this blood feature for assessing the body status. This parameter is one of the most labile features of blood that shows highly sensitive reaction to practically any changes in metabolic process in erythrocytes and in a whole body. Degradation of deformability of erythrocytes under various types of oxygen deficit deteriorates functioning of the system of oxygen transportation at various levels: heart, vascular flow, oxygen-transporting blood function. Under hypoxia the parameters of oxygen-transporting blood function, of peroxide oxidation of lipids and of the antioxidation system correlate well with degradation of deformability of erythrocytes. Therefore, this parameter can be used an integrated criterion of disturbances in oxygen supply, and of prooxidation-antioxidation body status. Deformability of erythrocytes is a factor generating adequate the oxygen supply to tissue, and its degradation aggravates substitution of the oxidase pattern of oxygen utilization with the oxygenase pattern. This parameter is extremely important for the body functional status.

Animals↗

PubMedDate not supplied

[Blood oxygen transport and pro-oxidant-antioxidant state during liver reperfusion].

Indices of blood oxygen transport (hemoglobin-oxygen affinity, pCO2, pH, pO2, etc.) and prooxidant-antioxidant state (Schiff bases, conjugated dienes, catalase, retinal, alpha-tocopherol) were measured in rabbit blood and the liver during postischemic reperfusion. Hepatic ischemia was induced for 30 min by ligation of a hepatica propria, and reperfusion lasted for 120 min. Hepatic ischemia worsened blood oxygen transport. Restoration of arterial blood flow did not result in improvement of oxygen delivery. Moreover, marked metabolic acidosis was observed throughout 2 hr of reperfusion. Ischemia induced a shift of oxyhemoglobin dissociation curve to the right. This shift persisted after restoration of hepatic arterial blood flow facilitating increased oxygen transport to tissues. Changes in blood oxygen transport during hepatic ischemia/reperfusion were accompanied with high activity of free radical processes. During reperfusion, the largest increase in content of lipid peroxidation products and the greatest fall of some antioxidant levels except catalase were observed indicating impairment of liver prooxidant-antioxidant balance. The results showed that activation of lipid peroxidation and a decrease in some antioxidant levels during hepatic reperfusion were associated with lowering of hemoglobin-oxygen affinity and suggest participation of the latter in impairment of prooxidant-antioxidant balance.

Acidosis↗

PubMedDate not supplied

[The involvement of nitric oxide in formation of hemoglobin oxygen-binding properties].

The analysis of literature and results of our investigations indicate the possible involvement of L-arginine-nitric oxide (NO) system in formation of blood oxygen-carrying capacity. In reaction with hemoglobin NO forms methemoglobin, nitrosyl-hemoglobin (HbFe2+NO) and S-nitrosohemoglobin (SNO-Hb). The NO-hemoglobin derivatives have the various biological functions (NO transport, storage, elimination etc.) and are involved in the genesis of different pathologic conditions. The presence of different NO-hemoglobin derivatives can differently influence on the whole blood hemoglobin-oxygen affinity (HOA): methemoglobin and SNO-Hb increases, and HbFe2+NO decreases it. Their effect on the blood oxygen-binding properties may be important for the gas exchange processes. At the level of lung capillaries such effect may be the additional mechanism promoting a blood oxygenation, and in the systemic microcirculation it may optimize blood desaturation and hence the tissue oxygen delivery. Blood oxygen-binding properties affect the state of L-arginine-NO system, however this system also may determine HOA through the intraerythrocytic regulatory mechanisms, oxygen-dependent nature of NO generation, regulation of vascular tone and effect of peroxynitrite.

Animals↗

PubMedDate not supplied

[Participation of the L-arginine-NO system in liver reperfusion injuries].

The L-arginine--NO system functioning in rabbits with hepatic ischemia and reperfusion was modified by infusing the NO synthase (NOS) inhibitor NG-nitro-L-arginine (15 mg/kg) or the NOS substrate L-arginine (300 mg/kg). The effect was evaluated by determining the lipid peroxidation (LPO) products (conjugated dienes, Schiff bases) and antioxidant system factors (alpha-tocopherol, retinol, catalase activity factor). The degree of reperfusive damage was evaluated by the alanine amino transferase (AlAT) and aspartate amino transferase (AsAT) activity in the blood of experimental animals. The development of ischemia and reperfusion leads to a significant growth in the LPO rate, depletion of the antioxidant system factors in the blood and liver tissue, and increase in the AlAT and AsAT activity. The L-arginine infusion prior to the reperfusion period decreased violation of the prooxidant-antioxidant state and favored normalization of the AlAT and AsAT activity in the blood. No such effects were observed as a result of the NOS inhibition prior to the onset of ischemia.

Alanine Transaminase↗

PubMedDate not supplied

[Effect of enalapril maleate and lozartan on the size of experimental myocardial infarction, hemoglobin affinity to oxygen and various parameters of lipid peroxidation].

The intravenous injections of enalapril maleate (0.1 and 0.5 mg/kg) and losartan (0.5 and 2.5 mg/kg) produced a 22-32% decrease in the size of myocardial infarction in rats with coronary ligation. This was accompanied by inhibition of the lipid peroxidation as revealed by the MDA test and Fe2+ induced chemiluminescence. Both drugs also increased the oxygen affinity of hemoglobin in the P50 test in vitro. Enalapril did not significantly alter the MDA level and superoxide dismutase (SOD) activity in the whole human blood. In contrast, losartan reliably inhibited SOD activity.

Angiotensin II↗

PubMedDate not supplied

[Involvement of oxygen-depending processes in the pathogenesis of hepatic reperfusion injury].

The disbalance between reactive oxygen species generation and antioxidant defensive factors importantly contributes in the development of hepatic reperfusion damage. Changes in blood oxygen transport during hepatic ischemia/reperfusion are involved in its development. Ischemia-induced oxyhemoglobin dissociation curve shift rightwards also exists during the hepatic reperfusion and thereby may facilitate the free radical attacks against the liver. The least disorders in blood oxygen transport, prooxidant-antioxidant balance and hepatic morpho-functional state were observed during the postischemic period under the conditions of moderate hypoxia. The protective effect of L-arginine during the hepatic ischemia-reperfusion may be partially due to the changed hemoglobin function and thereby tissue oxygen delivery and to the keeping of body prooxidant-antioxidant balance. The development of new pharmacological tools to modify the blood oxygen transport and generate the optimal nitric oxide amounts may be a promising strategy for correction of reperfusion injury.

Animals↗

PubMedDate not supplied

[The role of oxygen-binding properties of hemoglobin in the development of oxygen deficiency in acute exogenous hyperthermia].

Acid-base balance and oxygen-binding hemoglobin properties in mixed venous blood have been studied in 25 mongrel rabbits with acute environmental hyperthermia. As oxygen-hemoglobin affinity at standard pH, pCO2 and temperature increases, the effect of heat on oxygen-hemoglobin interaction is considerably attenuated. The Bohr effect increases. The mechanisms of changes in oxygen-binding properties of hemoglobin and their role in development of oxygen deficiency are discussed.

Acid-Base Equilibrium↗

PubMedDate not supplied

[An analysis of the changes in the basic parameters of lipid peroxidation and blood oxygen-transport function in pyrogenal-induced fever].

Content of main products of lipid peroxidation and hemoglobin affinity to oxygen were determined in mixed venous blood of rabbits during pyrogenal fever. Their relationships were studied on the basis of the factor analysis. The model of group structure of these parameters was obtained. It confirms the inducing influence of the rightward shift of the oxyhemoglobin dissociation curve on the processes of free-radical lipid oxidation.

Acid-Base Equilibrium↗