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Biomedical subjects

M V Ivanova

Publications and source records attributed to M V Ivanova.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

[Acidity and interaction with superoxide anion radical of echinochrome and its structural analogs].

Weak acid properties, autoxidation and interaction of natural polyhydroxy1,4-naphthoquinones (PHNQ) with superoxide anion-radical (O2-.) were studied by methods of potentiometric titration, polarography, and UV- and visible spectrophotometry. Sea urchin pigments 3-acetyl-2,6,7-trihydroxynaphthazarin (spinochrome C), 2,3,6,7-trihydroxynaphthazarin (spinochrome D), 2,3,6,7-trihydroxynaphthazarin (spinochrome E), 6-ethyl-2,3,7-trihydroxynaphthazarin (echinochrome A), synthetic 2,3-dihydroxy-6,7-dimethylnaphthazarin and 6-ethyl-2,3,7-trimethoxynaphthazarin (trimethoxyechinochrome A) were tested. Determined dissociation constants (pKi) were in the range of pH 5.3-8.5 (40% ethanol solvent). PHNQ autoxidation observrd in basic pH were inhibited by superoxide dismutase. Xanthine and xanthine oxidase was applied for O2-. generation. Interaction with O2-. led to sufficient time-dependent changing in spectra of echinochrome A, spinochromes D and E. There was weak O2-. influence on spinochrome C spectrum and no changing in trimethoxyechinochrome A spectrum. The spectra, that were transforming during time of reaction, contained pronounced isobestic point. It means formation the single reaction product. We proposed formation of 1,2,3,4-tetraketones from 2,3,5,8-tetrahydroxy-1,4-naphthoquinones (echinochrome A, spinochromes D and E) due to O2-.-induced oxidation of their OH-groups in 2 and 3 positions. Reaction constants were determined by competition method using nitro blue tetrazolium (NBT). The reaction constants were about 10(4)-10(5) M-1s-1. They were decreased in the order: echinochrome A > spinochrome D > spinochrome C > NBT > trimethoxyechinochrome A. Thus, we concluded that some of the natural PGNQ, containing hydroxyl groups in 2nd and 3rd positions, could operate as powerful superoxide anion-radical scavengers.

Antioxidants↗
PubMedDate not supplied

[Effect of antioxidant histochrome preparation on the contractile function and metabolism of the isolated rat heart under conditions of "calcium paradox", ischemia, and reperfusion].

A comparative study of protective effect of a new antioxidant histochrome on isolated rat heart at calcium paradox and ischemia-reperfusion was carried out. Perfusion with Ca-containing solution after 10-min perfusion with Ca-free medium caused depletion of high energy phosphates, loss of myoglobin, uncoupling of mitochondria, increase of left ventricular diastolic pressure. Pretreatment with histochrome led to decrease of cardiomyocyte damage evaluated by myoglobin efflux in perfused solution, attenuation of decrease ATP and phosphocreatine, and coupling of mitochondria. This resulted in a decrease of left ventricular diastolic pressure at calcium paradox. Less effect of histochrome treatment was noted in the case of ischemia-reperfusion model. It was concluded that histochrome effectively prevents heart from abnormalities caused by calcium imbalance in heart.

Adenine Nucleotides↗
PubMedDate not supplied

[Determination of fractional and subfractional blood lipoprotein compositions with small angle X-ray scattering (a comparison with a biochemical method)].

Highly accurate and fast method for determination of quantitative and qualitative compositions of serum lipoprotein (LP) fractions and subfractions, using small-angle X-ray scattering on the "Siemens" difractometr, has been developed. The method allows to determine the concentrations of serum cholesterol (CH), triglycerides (TG), high-density lipoprotein (HDL)-CH, low-density lipoprotein (LDL)-CH, phospholipides (FL) and total lipids. It allows to determine the levels of CH, TG, FL in LP subfractions and concentrations of 5 very-low-density lipoprotein, intermedius-density lipoprotein, 3 LDL (large, intermedius and small dense particles) and 5 HDL subfractions. The method is based on the elaborated united model of all LP fractions and subfractions as a result of generalization and analysis of literature data about LP composition and size. New method was proved to be highly reproductive. Strong positive correlation exists between serum levels of CH, TG, HDL-CH determined by enzymatic biochemical and our methods. The method is simple to perform and of high diagnostic value, and can, therefore, be applied to clinical purposes.

Cholesterol↗
PubMedDate not supplied

[The effect of ketoconazole on the cholesterol content of the blood serum lipoproteins and bile in experimental hypercholesterolemia].

Inclusion of ketonazole (in a daily dose of 400 mg/kg for 8 days) into the diet of intact and cholesterol-fed (5% dietary cholesterol) rats produced a respective 20- and 30-percent lowering of cholesterol content in blood serum. In all the animals, the hypocholesterolemic effect of ketoconazole was realized via a decrease of the concentration of very low and low density lipoproteins. Ketoconazole also gave rise to a reduction of the concentration of cholesterol and bile acids in bile of the intact rats and of cholesterol in bile of the cholesterol-fed animals.

Animals↗
PubMedDate not supplied

[Effect of ketoconazole on the activity of key enzymes of biosynthesis of cholesterol and its esters in the liver of rats maintained on a cholesterol-enriched diet].

Ketoconazole in vivo has been studied for its effect on the activity of key enzymes of the cholesterol and its esters' biosynthesis in the liver and on the cholesterol concentration in certain fractions of blood lipoproteins in normal and cholesterol-fed rats. It is established that ketoconazole decreases cholesterol concentration in low-density lipoproteins and in very low-density lipoproteins as well as decrease the acyl-CoA-cholesterol acyl-transferase activity and increases the 3-hydroxy-3-methyl-glutaryl-CoA-reductase activity in the liver microsomes of intact and test animals. It is supposed that the possible cause of the observed changes can be a disturbance in regulation of basic links of cholesterol metabolism in the liver.

Animals↗
PubMedDate not supplied

[The effect of verapamil and nifedipine on cholesterol esterification and accumulation in macrophages].

Administration of verapamil and nifedipine in doses of 10-75 microM into the culture of mouse peritoneal macrophages incubated in a non-lipid medium with acetylated low density lipoproteins (50 g protein/ml) decreased the incorporation of 14C oleate into cholesterol esters by 50-90%, increased the content of intracellular free cholesterol by 19-79% and did not influence the content of total cholesterol in macrophages. Administration of verapamil and nifedipine in doses of 25 and 50 microM in the culture of macrophages previously enriched with cholesterol reduced the rate of cholesterol esterification by 22-62%. After combined administration of verapamil and nifedipine in doses of 25 microM into the medium the rate of cholesterol esterification in macrophages fell by 72.4%.

Animals↗
PubMedDate not supplied

[Content of myosin-activating protein kinases in myocardium of patients with dilated cardiomyopathy and in the animal heart].

The skeletal myosin light chain kinase (skMLCK) was identified in human and chicken embryo myocardium but not in embryo and adult rat heart using western blotting. The content of skMLCK and myosin-activating protein kinases: RhaA-activated protein kinase (ROCK), integrin-linked protein kinase (ILK), and zipper-interacting protein kinase (ZIPK) was compared in normal human myocardium and the hearts of patients with dilated cardiomyopathy (DCM). It was demonstrated that the content of skMLCK, ROCK and ILK increases in DCM whereas the content of ZIPK decreases. The results obtained may reflect compensatory processes in cardiomyocytes in DMC, which are aimed at increasing their viability and contractility.

Age Factors↗
PubMedDate not supplied

[The correction of disorders in transcapillary metabolism in children with rheumatoid arthritis by using health resort therapy].

Children with rheumatoid arthritis in remission or minimal activity of the disease were examined after sanatorium treatment. It was established that health resort factors had produced a positive capillarotropic effect in rheumatoid arthritis, i.e. capillarotropic insufficiency, tissue hypoxia, inflammation and proteolysis reduced; microcirculation returned to normal.

Arthritis, Juvenile↗