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V V Zinchuk

Publications and source records attributed to V V Zinchuk.

At least 19 recordsLinked to original sources
PubMed2006

Prooxidant-antioxidant state of the organism during oxidative stress and correction of the L-arginine-NO system.

The prooxidant-antioxidant balance in rats with oxidative stress was studied during correction of the L-arginine-NO system. Oxidative stress was induced by intravenous injection of E. coli lipopolysaccharide. Under conditions of oxidative stress the prooxidant-antioxidant imbalance was least pronounced during selective correction of the L-arginine-NO system. L-Arginine and nonselective NO synthase inhibitor had little protective effect.

Animals↗
PubMed2006

The degree of oxidative stress in the rat brain during ischemia and reperfusion in conditions of correction of the L-arginine-NO system.

The aim of the present work was to evaluate oxidative stress in the brains of rats during ischemia/reperfusion in conditions of correction of the L-arginine-NO system. Experiments on 128 rats with brain ischemia/perfusion in conditions of modulation of the L-arginine-NO system were used to study changes in the concentrations of (a) lipid peroxidation products, i.e., diene conjugates, malonic dialdehyde, and Schiff bases, and (b) antioxidant protection factors, i.e., retinol, alpha-tocopherol, and SH-groups. Administration of L-arginine and NO synthase inhibitors, i.e., the non-selective inhibitor N(omega)-nitro-L-arginine methyl ester, the selective neuronal NO synthase inhibitor 7-nitroindasole, and the selective inhibitor of inducible NO synthase S-methylisothiourea, established that oxidative stress in rats with brain ischemia/perfusion is NO-dependent. NO formed by the various isoforms of NO synthase had different roles: hyperactivation of neuronal NO synthase was responsible for oxidative stress in both periods of brain ischemia/reperfusion, while increased inducible NO synthase activity was responsible in the late period.

Animals↗
PubMed2006

Nitric oxide effect on the hemoglobin-oxygen affinity.

The biological roles of nitric oxide (NO)-hemoglobin (Hb) derivatives are obscure. It is proposed that NO can function as an allosteric regulator of hemoglobin oxygen-binding properties. We aimed to estimate the effects of NO donors and NO-synthase substrate (L-arginine) on hemoglobin-oxygen affinity (HOA) in experiments in vitro with the various ratios between NO formed and Hb and various oxygen pressures. HOA index (p50), blood pH, plasma and red blood cell (RBC) concentrations of nitrite/nitrate and methemoglobin amounts were measured after the experiments. In our experiments, blood incubation with NO donors (glyceryltrinitrate, molsidomine, sodium nitroprusside, S-nitrosocysteine) or NO-synthase substrate (L-arginine) did not change HOA even at NO:Hb ratio of 1:1. At the same time our results showed that oxygenated blood incubation with S-nitrosocysteine induced an oxyhemoglobin dissociation curve shift leftwards. This indicates a leading role of met-Hb in a modification of Hb oxygen-binding properties. However other NO-modified forms of hemoglobin (S-nitroso- and nitrosylhemoglobin) also may be involved in the regulation of HOA. The results obtained indicate that nitric oxide can be the allosteric effector of hemoglobin, increasing or decreasing its oxygen affinity - possibly, through the generation of different NO-Hb derivatives.

Animals↗
PubMed2005

[The degree of cerebal oxidative stress in rats during ischemia-reperfusion combined with a modulaion of L-arginine-NO system].

We estimated the cerebral oxidative stress during ischemia-reperfusion of the brain in conditions of modulated L-arginine-NO system in rats. In 128 rats, the changes in lipid peroxidation products (conjugated dienes, malondialdehyde, Schiff bases) and antioxidant defense factors (retinal, a-tocopherol, SH-groups) were studied. Analysis of the inhibitor (administration of NO synthase substrate L-arginine, non-selective inhibitor Nw-nitro-L-arginine methyl ester, selective inhibitor of neuronal NO synthase 7-nitroindasole, or selective inhibitor of inducible NO synthase S-methyl-isothiourea) showed the NO-dependent nature of oxidative stress in rats with brain ischemia-reperfusion. NO generated by different NO synthase isoenzymes played different roles: hyperactivation of the neuronal NO synthase was associated with oxidative stress during both brain ischemia-reperfusion periods, and the higher inducible NO synthase activity had such association only during the later period.

Animals↗
PubMed2005

[Blood oxygen transport in rats during lipopolysaccharide administration combined with modification of L-arginine-No system].

Lipopolysacharide from Escherichia coli was intravenously administered to rats (5.0 mg/kg). L-arginine-No system was modified by intravenous injection of L-arginine, N(G)-nitro-L-arginine methyl ester or L-lysine-N(G)-acetamidine (nitric oxide synthase (NOS) substrate, nonselective NOS inhibitor, and selective inducible NOS inhibitor, respectively.) Lipopolysacharide-induced disorders of blood oxygen transport were the least during the selective inducible NOS inhibition. The protective effects of L-arginine and N(G)-nitro-L-arginine methyl ester were less prominent. Such features of NOS modification effect on the blood oxygen transport suggest that activation of inducible NOS may change the hemoglobin-oxygen affinity during the lipopolysacharide treatment.

Animals↗
PubMed2004

Blood oxygen transport and endothelial dysfunction in patients with arterial hypertension.

Disturbed nitric oxide (NO) synthesis leads to development of endothelial dysfunction that plays a significant role in the pathogenesis of arterial hypertension. The presence of various compounds of haemoglobin with NO can affect haemoglobin-oxygen affinity of the whole blood. Methaemoglobin and S-nitrosohaemoglobin increase it, whereas nitrosyl-haemoglobin decreases. The aim of this study was to investigate the blood oxygen transport indices and to assess the endothelial function in patients with arterial hypertension. The patients with mild hypertension had a 4.47% increased actual p50 (the blood pO(2) corresponding to its 50% oxygen saturation) (P<0.05), a diminished pO(2) (P<0.05), and a raised pCO(2) (P<0.01) as compared with the controls. The patients with severe hypertension had decreased pO(2) and pH, and actual p50 was reduced by 3.03% (P<0.05), which reflects a more pronounced oxyhaemoglobin dissociation curve shift leftwards. These changes can be assessed as a blood oxygen transport decompensation that enhanced tissue hypoxia. The results of our studies indicate that the endothelial dysfunction in patients with arterial hypertension leads to significant impairments in blood oxygen transport indices. The endothelium may be involved in development of the above blood oxygen transport impairments, since only sufficient amounts of NO maintain a normal blood flow and oxygen transport to tissues. The endothelial dysfunction leads to a disturbed production of different haemoglobin NO derivatives, which not only affects NO release at different sites of the arterial bed, but also haemoglobin-oxygen affinity and optimal blood oxygenation and deoxygenation in capillaries. These data support the notion that endothelial dysfunction may alter haemoglobin-oxygen affinity and tissue oxygen supply in vivo. Alternation of haemoglobin-oxygen supply may be involved in the pathogenesis of hypertension.

Adult↗
PubMed2004

Prooxidant-antioxidant balance in blood during the surgical treatment of obliterating arterial atherosclerosis in the lower extremities.

The chronic disorder of arterial circulation in the lower extremities due to the atherosclerotic injuries of the femoral-popliteal-tibial arteries was accompanied by the shift of the blood prooxidant-antioxidant balance towards more active free radical oxidation and by a depletion of antioxidant system. After restoring arterial blood flow in the ischemic lower extremities this balance was shifted towards more prominent lipid peroxidation processes. Such pattern of prooxidant-antioxidant balance changes implicates the development of strategies for its correction targeted on the reduction of lipid peroxidation activity and therefore on a tissue defense against the reperfusion injury.

Antioxidants↗
PubMed2003

Influence of different oxygen modes on the blood oxygen transport and prooxidant-antioxidant status during hepatic ischemia/reperfusion.

Oxygen supply was corrected in rabbits during the hepatic ischemia/reperfusion by means of different breathing mixtures: hypoxic (14.8 % O(2)+85.2 % N(2)), hyperoxic (78 % O(2)+20.2 % N(2)+ 1.8 % CO(2)), or hypercapnic (5 % CO(2) in air). Hepatic ischemia was induced for 30 min by ligation of hepatic artery, reperfusion period lasted 120 min. Indices of blood oxygen transport (p50(act), pCO(2), pH, pO(2), etc.) and prooxidant-antioxidant balance (Schiff bases, conjugated dienes, catalase, retinol, alpha-tocopherol) were measured in the blood and liver. The severity of reperfusion damage was evaluated by the activities of alanine and aspartate aminotransferases (ALT, AST) in the blood. Hepatic ischemia/reperfusion resulted in higher p50(act) in hepatic venous and mixed venous blood in all experimental groups. The changes of p50(act) were most marked in the hypercapnic group and were the weakest in the hypoxic group. The rise in p50(act) was accompanied by higher levels of lipid peroxidation products, ALT and AST in blood and liver homogenates, and by a simultaneous fall of alpha-tocopherol and retinol concentrations, except in the hypoxic group. Catalase activity at the end of reperfusion increased under normoxia, decreased under hyperoxia or hypercapnia and did not change under hypoxia. The moderate hypoxia during reperfusion was accompanied by a better balance between the mechanisms of reactive oxygen species production and inactivation that may be observed by optimal changes in p50act and reduced the hepatic damage in this pathological condition.

Alanine Transaminase↗
PubMed2002

Blood oxygen transport in rats under hypothermia combined with modification of the L-Arginine-NO pathway.

Nitric oxide (NO) has high affinity to heme and by interaction with oxyhemoglobin (HbO2) is converted into nitrate to form methemoglobin (MetHb) as a side product. In combining with deoxy-Hb NO yields a stable molecule of nitrosyl-hemoglobin (HbFe(II)NO) that can further be converted into nitrate and hemoglobin (Hb). In addition, Hb was shown to transport NO in a form of S-nitrosohemoglobin (SNO-Hb). These features of the Hb and NO interaction are important for blood oxygen transport including hemoglobin-oxygen affinity (HOA). The present investigation was aimed to study the blood oxygen transport indices (pO2, pCO2, pH, HOA, etc.) in rats under hypothermia combined with a modification of L-arginine-NO pathway. To modify the L-arginine-NO pathway, rats were administered with N(G)-nitro-L-arginine methyl ester (L-NAME), L-arginine, or sodium nitroprusside (SNP) intravenously before cooling. A substantial impairment of oxygen delivery and development of hypoxia, with an important contribution of HOA into the latter accompanied the deep hypothermia in rats. All the experimental groups developed metabolic acidosis, less pronounced in rats treated with L-arginine only. In the experiments with a modification of the L-arginine-NO pathway, an enhanced cold resistance, attenuated oxygen deficiency, and a weaker oxyhemoglobin dissociation curve (ODC) shift leftwards were observed only after the administration of L-arginine. Neither SNP nor L-NAME had not any protective effects. L-Arginine lowered the value of standard P50 (pO2, corresponding to 50% Hb saturation with oxygen at 37 degrees C, pH 7.4, and pCO2 = 40 mmHg). The actual P50 (at actual pH, pCO2 and temperature) decreased by approximately 15 mmHg and was significantly higher than that under hypothermia without the drug treatment (21.03 +/- 0.35 vs 17.45 +/- 0.60 mmHg). NO also can contribute to this system through different mechanisms (HOA modification, vascular tone regulation, peroxynitrite formation, and effects).

Animals↗
PubMed2001

Prooxidant-antioxidant state after administration of lipopolysaccharide during correction of the L-arginine-NO system and affinity of hemoglobin for oxygen.

We studied the effect of correction of the L-arginine-NO system on the fever reaction and prooxidant-antioxidant state in rats with increased hemoglobin oxygen affinity caused by sodium cyanate after intramuscular injection of lipopolysaccharide. The imbalance between parameters of the prooxidant-antioxidant state in rats with increased hemoglobin oxygen affinity was least pronounced after lipopolysaccharide administration. Correction of the L-arginine-NO system in rats with increased hemoglobin oxygen affinity had no effect on the contents of Schiff bases and antioxidants after lipopolysaccharide administration.

Animals↗
PubMed1995

Analysis of the relationship between hemoglobin-oxygen affinity and lipid peroxidation during fever.

Endogenous hyperthermia was induced in rabbits by i.v. pyrogenal administration. Hemoglobin-oxygen affinity and parameters of free radical lipid oxidation in plasma and red blood cells were measured. The content of diene conjugates, malonic dialdehyde and Schiff bases were determined at a pyrogenal dose of 4 minimal pyrogenic doses/kg, and iron-initiated chemiluminescence, catalase activity and alpha-tocopherol concentration were determined at 6 minimal pyrogenic doses/kg. A rightward shift of the real oxyhemoglobin dissociation curve and activation of lipid peroxidation were observed. Relationships between the parameters measured were analyzed. Decreased hemoglobin-oxygen affinity is considered to be a possible mechanism of activation of free radicals during fever.

Animals↗
PubMed1992

[The effect of sodium cyanate-modified hemoglobin oxygen affinity on the heat resistance of rats].

Regression analysis of relationship between rat hemoglobin-oxygen affinity (HOA) and rectal temperature has shown a close positive correlation of these parameters. Heat resistance (HR) was examined in rats with HOA elevated by sodium cyanate in order to recognize the contribution of HOA to a process of body heat adaptation. Our data suggest that HR of treated rats was larger than in control animals. These results are discussed in relation with antioxidant type of the cyanate elevation in HOA.

Adaptation, Physiological↗
PubMed1989

[Oxygen transport function of the blood in hyperthermia in rabbits].

After 30-min or longer incubation of rabbit blood under 42 degrees C the blood O2 affinity was increased. During governed hyperthermia of conscious rabbits PO2, pH and the oxygen content in the mixed venous blood were decreased. Similar events were observed after 1 hour from the ceasing of hyperthermia. In the real blood circulation the oxygen affinity of haemoglobin was decreased because of the higher temperature. But after the recalculation of P50 to the standard conditions (t = 37 degrees C, pH 7.4, PCO2 = 40 Torr) it's value was below the initial one by 4.0 +/- 0.68 Torr. The mechanism of the increase of the oxygen affinity of haemoglobin is discussed.

2,3-Diphosphoglycerate↗
PubMedDate not supplied

[The role of the oxygen-binding properties of the blood in maintaining pro-oxidant-antioxidant equilibrium in the body].

Tissue pro-oxidant generation under standard conditions is equilibrated with the activity of intra- and extracellular antioxidants; thus some optimal level of pro-oxidant-antioxidant balance is created. Oxygen-dependent nature of lipid peroxidation processes implicates its complex multilevel regulatory system, where systemic mechanisms may dominate upon the intracellular ones. This suggests a necessity in the investigation of body oxygen transport not only in terms of the requirements of energetic metabolism in electron acceptor but also as a physiological mechanism for antioxidant defense and, in general, as the mechanism involved in a maintenance of pro-oxidant-antioxidant balance. The hemoglobin-oxygen affinity has a special place in a complex antioxidant system hierarchy, because it determines the condition of oxygen diffusion to tissues and ultimately the value of tissue pO2. The blood oxygen-binding properties under different hyperthermic states with or without a correction of hemoglobin-oxygen affinity and L-arginine-NO pathway were shown to be involved into a complex integration with elements of different functional systems and to play an important role in complex physiologic mechanisms for the maintenance of pro-oxidant-antioxidant balance. The oxyhemoglobin dissociation curve shift leftwards may have an adaptive effect under conditions of low oxygen utilization because of limitation of oxygen fraction spent on a free radical generation and the following initiation of lipid peroxidation processes.

Animals↗