Role of proinflammatory factors, nitric oxide, and some parameters of lipid metabolism in the development of immediate adaptation to hypoxia and HIF-1α accumulation.

The development of immediate and delayed long-term resistance to hypoxia during a course of intermittent normobaric hypoxia (15 daily sessions of alternating exposure to 10% O2 and atmospheric air for 1 h) correlated with biphasic expression of HIF-1α in neocortex of hypoxia-intolerant rats, which suggests involvement of this protein factor not only in the formation of long-term adaptation, but also in triggering immediate adaptation to hypoxia. Both processes develop under conditions promoting down-regulation of oxidative modification of LDL and increasing tolerance of biological membranes to hypoxia in the absence of activation of the free radical processes, which therefore do not trigger HIF-1α expression under these conditions. Neither cytokines nor NO are the inducers of immediate adaptation, and they are not related to HIF-1α expression during the early post-hypoxic period. In contrast, long-term adaptation in response to the course of intermittent normobaric hypoxia develops against the background of enhanced NO production, activation of pro- and anti-inflammatory factors, and expression of VEGF, the marker of angiogenesis. Therefore, all these factors can promote activation of transcription processes required to form the long-term adaptation.

Mechanism of cardioprotective effect of adenocine and non-glycoside cardiotonic drugs during experimental chronic cardiac insufficiency.

The therapeutic action of adenocine during cardiac insufficiency (heart failure) caused by ischemic (stenosis) or reperfusion (removal of ligature) injury to the myocardium prevents depletion of ATP, the major energy source for myocytes in the right and left ventricles, and a drop in NAD/NADH ratio. The development of energy shortage during heart failure cannot be eliminated by ß-acetyldigoxin, levosimendan, or milrinone: the content of ATP in the right and left ventricular myocardium remained below the normal level by 28 and 29%, 37 and 33%, 32 and 28%, respectively; the NAD/NADH ratio of the energy supply system in cardiomyocytes did not return to normal. Adenocine increased the content of NAD to the normal level in both the right and left ventricles, while it remained below the normal level after administration of ß-acetyldigoxin (by 24 and 19.5%, respectively), levosimendan (by 27 and 29%), and milrinone (by 26 and 24%). In contrast to ß-acetyldigoxin, levosimendan, and milrinone, adenocine inhibited activity of poly(ADP-ribose) polymerase in both ventricles. It is concluded that adenocine directly inhibits the key enzyme triggering apoptosis; we also hypothesized that this drug activates the regulatory and signal mechanisms arresting apoptotic alterations in the myocardium during heart failure.

Comparative therapeutic efficacy of adenocin and non-glycoside cardiotonic drugs in chronic heart failure at rest and under conditions of heart overload.

Experiments were performed on the model of chronic heart failure. Functional capacity of myocardial structures under conditions of maximum pressure overload was within the upper limit of normal after treatment with Adenocin. The myocardial functional reserve and potential capacity index were shown to increase to normal under these conditions. Dobutamine, levosimendan, and milrinone increased functional capacity under conditions of maximum pressure overload. Treatment with adenocin restored diastolic function of the heart under conditions of maximum pressure overload. The end-diastolic pressure increased, but remained 1.7 times below the level observed in heart failure. After treatment with dobutamine and milrinone, the end-diastolic pressure (8th episode of ligation) did not differ from the level observed in heart failure, while after administration of levosimendan this parameter decreased by 31%. Contraction-relaxation coupling was completely restored under the influence of Adenocin in all episodes of ligation both before and after removal of the ligature. Nearly all animals with heart failure were resistant to 8 episodes of ligation after treatment with Adenocin (89 vs. 96% under normal conditions). Under these conditions, the survival rate of animals after administration of levosimendan, milrinone, and dobutamine was 65, 60, and 61%, respectively, (the mortality rate of animals with heart failure was 75%). Adenocin, a cardiotonic drug with cardioprotective properties, in contrast to other cardiotonic drugs, has a modulatory effect on the system of cell energy supply, restores myocardial reserves, and improves myocardial function under conditions of overload.

Rational drug correction of systemic inflammatory response syndrome in severe experimental heart failure.

A course of adenocine (cardiotonic drug with a pronounced cardioprotective effect) for severe experimental heart failure caused by toxic allergic myocarditis (for 10 days) more effectively restored the systolic and diastolic function of the heart and arrested systemic inflammatory response syndrome than traditional therapy with angiotensin-converting enzyme inhibitors, beta-adrenoblockers, or diuretics in combination with neoton. Adenocine is characterized by a synergistic effect, and none of its ingredients alone (nicotinamide adenine dinucleotide, inosine, beta-acetyldigoxin, oxyfedrine) exhibits similar effect.

Effect of nadcin on energy supply system and apoptosis in ischemia-reperfusion injury to the myocardium.

Nadcin in a dose of 90 mg/kg administered to dogs with subacute stage of ischemia-reperfusion myocardial injury immediately after blood flow resumption normalized redox potential of cardiomyocytes and mitochondria and restored the total content of adenyl and pyridine nucleotides. The decrease in the synthesis of ATP and pyridine nucleotides and reduction of the redox potential of the energy supply system were inversely related to the increase in poly-(ADP-ribose)-polymerase activity in the ischemic area and nonischemic region. Nadcin abolished the increase in poly-(ADP-ribose)-polymerase activity in the ischemic area of the right ventricle, nonischemic region, and ischemic area of the left ventricle (by 2.4, 2.9, and 1.52 times, respectively) and normalized bioenergetic activity of cardiomyocytes during ischemia-reperfusion myocardial injury.

Structural and functional changes in myocardial thin filaments in experimental hypothyrosis.

Fluorescence resonance energy transfer study revealed decreased intermonomer mobility of Ca-actin and Mg-actin filaments of myocardial myofibrils in myocardial dystrophy caused by diffuse endocrine disorders, e. g. hypothyrosis. Cis374 axial distance in Ca-actin filament protomer increased in hypothyrosis. Intracellular pH has no effect on inter-monomer mobility of Ca-actin filament.

Submolecular mechanisms underlying in vitro and in vivo effect of cardiac glycosides on contractile activity of myocardial myofibrils during heart failure.

The development of severe heart failure associated with toxicoallergic myocarditis is accompanied by profound structural and conformational changes in the outer domain of actin (major protein in a thin filament of cardiomyocyte sarcomere). These changes were revealed in subdomains 1 (Cys374 and Cys10) and 2 (Lys61 and Tyr69). Structural and conformational changes in the monomer and protomer of the actin thread during heart failure were energetically forbidden. Variations in the distance between amino acid residues exceeded 0.26 nm. They were partly or completely reversible in vivo under the influence of cardiotropic drug refracterin with high antihypoxic activity, as well as in vitro after treatment with digitalis preparations optimizing the concentration of ATP.

Effectiveness of combined treatment with superoxide dismutase and Reamberin during skin ischemia.

Experimental skin ischemia in rats was induced by suturing a skin fold on the back with a silk thread. Combined pretreatment with superoxide dismutase (intraperitoneally) and Reamberin (intravenously) in doses of 0.01 and 6.25 mg/kg (by succinate concentration), respectively, produced a strong protective effect on the skin. The index of cytolysis decreased by 39%. The more pronounced antinecrotic effect of combined treatment with superoxide dismutase and Reamberin compared to the effect of Reamberin alone was related to a sharp increase in the reserve capacity of the antioxidant system. After combined therapy, activity of antioxidant defense enzymes not only increased, but even exceeded the normal level. The increase in activity of endogenous superoxide dismutase under the influence of combined therapy was accompanied by suppression of superoxide anion production.

Antinecrotic and antioxidant effects of superoxide dismutase during skin ischemia.

Antinecrotic activity of SOD was studied in rats with experimental skin ischemia. Treatment with SOD increased activity of endogenous SOD in skin homogenates (by 70 and 26% compared to the ischemic and intact skin, respectively). However, the rate of superoxide anion generation remained unchanged after SOD treatment. Creatine phosphate content and NAD/NADH redox potential increased by 16 and 21%, respectively, on day 3 after SOD administration. The increase in functional activity of the energy supply system and rise in the reserve capacity of the antioxidant protection system contribute to inhibition of lactate dehydrogenase and creatine phosphokinase and decrease in the cytolysis index under the influence of SOD. Our results indicate that SOD produces the antinecrotic effect and holds much promise for the therapy of skin ischemia.

Pharmacological correction of changes in the lung-placenta system under experimental conditions.

Pathological changes in the fetoplacental complex and lung-placenta system were observed in rats with experimental gestosis produced by long-term feeding of a high-sodium diet. We revealed a decrease in the weights of the placenta and fetus, pulmonary fibrinolytic dysfunction, and increased production of cortisol. The course of fraxiparine treatment in animals with experimental gestosis decreased coagulation activity of the arterial blood, increased the weights of the placenta and fetus, and reduced the concentration of stress hormone cortisol.

Disorders in the lungs-placenta system under conditions of experimental gestosis in rats.

Study of the arteriovenous difference in hormone levels and hemostasis parameters in rats with experimental gestosis induced by hyper-sodium diet showed decreased production of progesterone, increased level of hydrocortisone (resultant from its increased production and additional release of the hormone by the lungs), hypercoagulation, and retarded fetal development. Involvement of the lungs into the maintenance of optimum rheological parameters of arterial blood and a relationship between the level of fetoplacental hormones and the function of pulmonary fibrinolytic filter were detected.

Effect of nonselective beta-adrenoblockers on the state of sympathoadrenal system and ratio of neuroactive amino acids in rat medulla oblongata.

Experiments on rats showed that injection of propranolol into the medulla oblongata increased the contents of epinephrine, norepinephrine, dopamine, and L-DOPA by 3.76, 1.4, 2.0, and 1.7 times, respectively. These propranolol-induced changes in the levels and ratio of neurotransmitters were not accompanied by variations in serotonin content. Propranolol had no significant effects on the content of excitatory amino acids, except marked increase in aspartate content. The level of inhibitory amino acids increased mainly due to an increase in GABA content. The balance between excitatory and inhibitory amino acids was shifted towards inhibitory compounds.

In vitro effects of gentamicin, ampicillin, and cefobid on energy supply and antioxidant protection systems of venous blood erythrocytes in newborns.

We studied the effects of antibiotics of different classes on reserve capacities of the energy supply and antioxidant protection systems in newborns. Erythrocyte catalase activity was high in children with perinatal asphyxia. Penicillin antibiotics, aminoglycosides, and cephalosporins decreased enzyme activity of the glutathione-associated antioxidant system. Ampicillin most significantly inhibited ATP synthesis in erythrocytes under conditions of hypoxia. Gentamicin was least potent in this respect. Impairment of ATP synthesis in erythrocytes was associated with inhibition of antioxidant enzymes catalase and glutathione reductase. Ampicillin increased glutathione peroxidase activity in response to addition of H2O2. None of the antibiotics modulated activity of cytosolic superoxide dismutase in blood erythrocytes from healthy newborns and newborns with perinatal asphyxia.

Relationship between immune status and activity of the lymphocyte energy supply system in adolescents suffering from frequent diseases.

Children and adolescents aged 4-16 years with the diagnosis of acute respiratory viral infection with long-lasting fever, manifestations of intoxication syndrome, and catarrhal symptoms were examined. In children and adolescents suffering from frequent diseases and presented with acute respiratory viral infection we found disorders in the immune status (depression of the cellular component, helper/suppressor imbalance, suppressed production of IgA and hyperproduction of IgM, decreased concentration of secretory IgA in the saliva) in comparison with children rarely falling ill. The redox potential and lymphocyte cytochrome C content were decreased in adolescents often falling ill, while the content of cytochrome oxidase did not change. A negative multiple correlation (R=6.8, p<0.005) was detected between the decrease in cytochrome C content and NADP/NADPH redox potential and increase in the immunoregulatory index. ATP content in lymphocyte from adolescents frequently falling ill remained 21% decreased during the first 2 weeks after acute respiratory viral infection, while the ATP/ADP ratio was shifted towards dinucleotide, which also indicated disorders in ATP synthesis in lymphocytes.

Effect of NAD on recovery of adenine nucleotide pool, phosphorylation potential, and stimulation of apoptosis during late period of reperfusion damage to myocardium.

The system of energy supply in the myocardium of the left and right ventricles did not recover after short-term circulatory disturbances. ATP synthesis decreased in parallel with activation of poly-(ADP-ribose)-polymerase in the ischemic region of the right ventricle, extra-ischemic region, and in the left ventricle by 5.85, 5.4, and 2.2 times, respectively. Intravenous injection of NAD immediately after blood flow resumption in the subacute period of ischemia-reperfusion damage virtually completely normalized the pool of adenine nucleotides, energy change of the adenine nucleotide system, and phosphorylation potential. Exogenous NAD inhibited activity of poly-(ADP-ribose)-polymerase in the ischemic region of the right ventricle, extra-ischemic region, and in the ischemic region of the left ventricle by 2.4, 2.9, and 1.52 times, respectively. We hypothesize that NAD acts as a regulator of signal mechanism of apoptosis induction during ischemia-reperfusion damages to the myocardium.

Antihypoxic and antinecrotic effect of mexidol in skin ischemia.

Course treatment with mexidol in a dose of 25 mg/kg for 3 days decreased activities of aspartate transaminase and creatine phosphokinase in the plasma on day 3 after the incidence of skin ischemia (by 1.3 and 1.66 times, respectively). Under these conditions the index of cytolysis decreased by 1.3 times. Therefore, mexidol prevented progression of necrotic processes in the skin. Mexidol therapy of animals with skin ischemia restored the reserve capacity of systems for energy supply and antioxidant defense. The systems of NADH-ubiquinone reductase and succinate-ubiquinone reductase served as the targets for the action of mexidol. Mexidol significantly decreased the damaging effect of reactive oxygen species. Dermatoprotective properties of mexidol were associated with its influence on the energy supply system (regulation of enzyme activity in the electron transport chain, ubiquinone metabolism) and antioxidant defense.

Structural and conformational changes in myocardial and erythrocyte actin during cardiac ischemia.

Structural and conformational changes in myocardial and erythrocyte actin during cardiac ischemia were studied by the method of fluorescence resonance energy transfer with highly selective fluorescent probes. In contrast to 15-min coronary artery occlusion, 120-min ischemia was accompanied by irreversible structural and conformational changes in the small domain of erythrocyte actin. Posttranslational changes during myocardial ischemia concerned the N- and C-terminal regions of actin and went beyond the allowed conformational fluctuations in the actin molecule without breaking the energy barrier. Our results suggest that under conditions of ischemia, actin of the myocardium and erythrocyte cytoskeleton loses its ability to acquire conformation required for force generation by cardiomyocyte myofibrils and maintenance of elasticity and integrity of the erythrocyte membrane.

Protective effect of reamberin on functional activity of mitochondria during skin ischemia.

Reamberin in a dose of 25 mg/kg (succinate concentration) was injected intravenously for 3 days starting from the 1st hour after skin ischemia modeling. This treatment decreased activities of lactate dehydrogenase, aspartate transaminase, and creatine phosphokinase in skin homogenates by 1.6 times, 19%, and 51.3%, respectively. The index of cytolysis decreased by 18%. Reamberin had an energotropic effect, which manifested in an increase in the total ATP content and concentration of creatine phosphate (by 16 and 10%, respectively). After administration of Reamberin, activity of the succinate-ubiquinone reductase system increased by 17%. Under these conditions succinate dehydrogenase activity exceeded the normal by 21%. Reamberin had no effect on the mitochondrial NADH-ubiquinone reductase system in dermal cells during skin ischemia. Superoxide dismutase activity in the area of necrosis increased to the control level on day 3 of treatment with Reamberin. Activities of catalase and glutathione peroxidase increased by 13 and 19%, respectively. Our results indicate that the course of intravenous treatment with Reamberin for 3 days contributes to an increase in reserve capacities of the antioxidant protection system and produces a protective effect during skin ischemia.

Mechanism of protective effect of energostim during catalepsy produced by single treatment with trifluoperazine.

NAD, cytochrome c, and energostim modulated the fluorescence emission spectrum of trifluoperazine in the solution and in microsomal suspension. The data suggest that NAD and energostim modify structural and conformational characteristics of the dopamine receptor-trifluoperazine complex. These changes probably underlie the anticataleptic effect of energostim.

Anticataleptic effect of energostim during single treatment with trifluoperazine.

Administration of trifluoperazine in a single dose of 3 mg/kg induced catalepsy and locomotor disorders in 86% intact animals, which persisted for 4 h. Catalepsy developed in only 15% animals pretreated with antihypoxic and antioxidant agent energostim in a dose of 230 mg/kg. The protective effect of energostim was associated with its ability to maintain the balance between dopaminergic, cholinergic, and adrenal activity in the substantia nigra and medulla oblongata during administration of neuroleptics.