[Alterations of tissue blood supply of experimental animals at malignant tumor growth].

The aim of the research was to study tissue blood flow in the dynamics of malignant tumor growth (Ehrlich carcinoma of 80 mice, sarcoma--37-80 rats, 30 rabbit--Brown-Pirs carcinoma) in functionally different organs of experimental animals (mice, rats, rabbits): skeletal muscles, liver, ear, mammary gland and ciliary body of eye. The study was conducted using H clearance method. Deformability of erythrocytes was studied using filtration-photometry method. Blood surface tension was studied by Rebinder bubble maximal pressure method. Obtained data were analyzed by Student's t criterion. The investigation showed that intensity of local hemocirculation and erythrocytes deformability in "intact" organs and tissues of experimental animals in the dynamics of malignant tumor growth progressively decreases while, blood surface tension increases. It was revealed that paraneoplastic disorders of local hemocirculation were stereotyped, universal and common phenomenon for malignant tumor growth. It was concluded that alterations of blood rheology decreased deformability of erythrocytes and increased blood surface tension play one of the leading roles in the mechanism of paraneoplastic disorders of local hemocirculation.

[Molecular mechanisms of apoptosis].

Apoptosis is the vital issue of Biology and Medicine. Recent concept of molecular and cellular mechanisms of apoptosis--a well-controlled form of cell death was reviewed. The aim of a review was to broaden knowledge of apoptosis mechanism and to reveal molecular targets for the modulation of these processes. The data on the apoptosis was analyzed. The biological role of physiological cell death in normal state and in different human pathologies is described. The literature data showed that many molecular mechanisms of apoptosis are still unknown. Three mechanisms are actually known to be involved in the apoptotic process: a receptor-ligand mediated mechanism, a mitochondrial pathway and a mechanism in which the endoplasmic reticulum plays a central role. Morphological and biochemical definitions of poptosis are presented. An original scheme of apoptosis mechanisms is constructed. The term "mediators of poptosis" is introduced. Extra cellular and intracellular mechanisms of apoptosis are examined. The special attention is paid to mitochondrial factors of apoptosis, Ca(2+)-ions, and proteins (Bcl-2, Bax, p-53).

[The role of changes in tissue redox-status in mechanism of paraneoplasia].

To specify mechanisms of paraneoplastic alterations of redox-status of tissues in experimental malignant tumor growth, we investigated electronic paramagnetic centers of blood, skeletal muscle and liver with electronic paramagnetic resonance (EPR) method. We also studied the concentration and activity of antioxidant enzymes. Our experiments on adult white male rats of mixed population with sarcoma C-45 and mice with Ehrlich carcinoma have shown that malignant tumor growth leads to enhanced lipid peroxidation (LPO): production of potent LPO promoters - Fe2+, Mn+2+, NO, ubiquinone; depression of antioxidant defence - reduced production of total ceruloplasmin, elevated blood levels of oxidized ceruloplasmin and enhanced catalase activity. It is suggested that malignant tumor growth is associated with marked paraneoplastic shifts in tissue redox-potential. These alterations are involved in mechanisms of paraneoplastic changes of red cells, microhemocirculation and circulation intensity. All these interrelated processes result in generalized paraneoplastic hypoxia of the organs and tissues. Basing on our and literature data, we propose an original scheme of the mechanisms of paraneoplastic disorders of tissue redox-status, microcirculation and erythrocytes.

[Biochemical and clinical aspects of melatonin biosynthesis induced by noradrenalin in experiment].

Melatonin has been considered as a hormone with potent immunomodulating, anxiolitic and antioxidative properties. Melatonin is also known to be inhibitor of sympatoadrenal activity. The study was aimed to elucidate changes in melatonin synthesis induced by noradrenalin IM injection. Melatonin plasma levels were detected by radioimmunoassay. All studies were performed conducted on white non-linear rats. By the 20th day after noradrenalin administration plasma level of melatonin was significantly decreased. In conclusion, short-term activation of sympatoadrenal system (i.e. stress-induced activation) is accompanied by elevated plasma levels of melatonin, however long-term hyperactivity of the sympatoadrenal system atrophy of epiphiseal parenchyma develops followed by decreased melatonin synthesis. It has been considered that melatonin might contribute to chronic stress-induced process associated with involution of thymus and lymphatic nodes, hypertrophy of adrenal cortex. Data obtained might be taken into consideration during the treatment of stress-induced conditions.

[Biochemical, pharmacological and clinical aspects of influencing methioninc, tryptophan, pyridoxine (vitamin B6), Ca2+ and high-calorie food on the synthesis and intensity of the secretion of melatonin].

The goal of the investigation was the determination of the influence of Ca(2+), vitamin B6 methionine, tryptophan, the combination of the listed elements and high-calorie food on the intensity of synthesis and secretion of melatonin. The level of melatonin in the blood serum was being determined through the method of radio-immune (immune-enzyme) analysis. Based on the results received it was found out that the influence of the vitamin B6, tryptophan and their combination in the organism of the tested objects - white rats) resulted in the considerable increase of formation of melatonin. In the conditions of feeding them with high-calorie food - the value of melatonin in blood is sharply reducing. Consequently we may conclude that the vitamin B6 and tryptophan separately and in combination, either directly or through some other mechanism participate actively in biosynthesis and secretion of melatonin. The high-calorie food through unknown mechanism to us reduces the formation of the melatonin in epiphysis. This might point to the important role of the deficit of melatonin in etiopathogenesis of the diseases, detected and developed on the background of hypercholesterinemy.

[Role of peroxidation processes and nitric oxide in mechanisms of paraneoplastic alterations of hemocirculation].

The present work was aimed to study mechanisms of paraneoplastic alterations of tissue redox-status, intensity of local blood flow in liver and their possible interrelations in case of malignant tumor growth. It has been investigated the electronic paramagnetic centres of blood and liver using the electronic paramagnetic resonance (EPR) method and intensity of local hemocirculation with the use of H(+) clearance polarography method. Experiments have been carried out on adult white rats of mixed population with carcinoma Walker and mice -- with carcinoma Ehrlich. It has been shown that malignant tumor growth displays conditions that lead to exaggerated lipid peroxidation (production of POL promoters -- Fe(2+), Mn(2+), NO, ubiquinone) and suppression of antioxidant protection of organism (reduction of total ceruloplasmin concentration in blood and increased concentration of oxidized ceruloplasmin). It has been suggested that in case of malignant tumor growth sharp paraneoplastic alterations of redox-status plays essential role in mechanisms of paraneoplastic disorders of tissues blood supply. All of these interrelated processes result in generalized paraneoplastic hypoxia in organs and tissues.