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Biomedical subjects

W Rzeczycki

Publications and source records attributed to W Rzeczycki.

At least 19 recordsLinked to original sources
PubMed1992

Effect of mesitylene on ethanol metabolism in rat liver microsomes.

Increased catalase activity was observed in the liver microsomal fraction of ethanol-treated rats (10% v/v aqueous ethanol solution per os for 5 weeks). In contrast, cytochrome P-450 concentration and specific activity of NADPH-cytochrome c reductase remained at the same level as in the liver of control rats (drinking water). The ratio of microsomal H2O2-generation to catalase activity was lower in the "ethanol" group than in the control one. This phenomenon seems to be related to the increased contribution of the "peroxidatic" reaction (increased rate of ethanol oxidation). Administration of mesitylene (1,3,5-trimethylbenzene) by gastric tube for 3 days (5 mmoles per kg daily) increased cytochrome P-450 concentration, specific activity of NADPH-cytochrome c reductase and ethanol metabolism.

Alcoholism↗
PubMed1988

Effect of styrene and other alkyl benzene derivatives on oxidation of FAD- and NAD-linked substrates in rat liver mitochondria.

The effect on energetic metabolism of rat liver mitochondria (RLM) of styrene and other aliphatic benzene derivatives, i.e. toluene, ethylbenzene, alpha-methylstyrene and butylbenzene, is studied. It is shown that these compounds uncouple oxidative phosphorylation and this effect is connected with the stimulation of passive entry of protons into mitochondria. The relationship between hydrophobicity of these compounds and their biological activity and mechanism of uncoupling effect are discussed.

Adenosine Triphosphatases↗
PubMed1988

On the mechanism of glycolysis stimulation by mitochondria from Guérin epithelioma.

The experiments were performed to determine the factor(s) responsible for the stimulatory effect on glycolysis in the cytosol (post-microsomal supernatant) of mitochondria isolated from Guérin epithelioma. It was found that epithelioma mitochondria contain bound hexokinase which constitutes about 50% of the total cellular hexokinase activity. The solubilized and partially purified enzyme, when added to the cytosol, stimulated glycolysis. The stimulatory effect of mitochondria on glycolysis was associated with the decrease of adenylate energy charge which was caused by an apparently very fast production of ADP in the hexokinase reaction. A large part of ATP hydrolyzed in this process was converted to IMP and NH3, which can additionally stimulate glycolysis through its stimulatory effect on phosphofructokinase. It is therefore suggested that the stimulatory effect of epithelioma mitochondria on glycolysis can be explained by production of ADP by the hexokinase associated with these mitochondria.

Adenosine Diphosphate↗
PubMed1981

Specific, antigenic protein of Guerin epithelioma.

Specific, antigenic protein of the molecular weight 61 000 and 66 000 and isoelectric point 5.15 were isolated from cytosol of Guerin epithelioma and antiserum against these proteins was obtained. These antigens appear to be specific for epithelioma. Such antigens were not found in any normal rat organ. Blood serum of Guerin epithelioma bearing rats does not contain antibodies against these antigens.

Animals↗
PubMed1980

Cytoplasmic 14C-labeled arginine basic proteins of Ehrlich ascites tumour cells.

With the use of 14C-arginine it is shown that among soluble cytoplasmic proteins of Ehrlich ascites tumour cells there appear basic proteins rich in arginine with the content of amino acid higher than 14%. The amount of these proteins is about 10%. The role of arginine-rich basic proteins in the cytoplasma is briefly discussed.

Animals↗
PubMed1978

Collagen-bound glycoprotein of Guerin epithelioma.

The polymeric collagen of Guerin epithelioma is strongly bound to a large amount of noncollagenous substance. Almost full dissociation of this complex was achieved by heating in 7 Murea, at 100 degrees C for 4 hours. The collagen bound substance was identified as an acidic glycoprotein containing glucose, galactose, glucosamine, galactosamine and M-acetylneuraminic acid. Heterogeneity of this substance in regard to molecular weight was found.

Amino Acids↗
PubMed1977

Characterization of cytoplasmic arginine-rich basic protein of Guerin epithelioma.

Arginine-rich basic protein from cytoplasma of Guerin epitheliomas has been isolated and characterized. It contains five amino acids: arginine, lysine, glycine, alanine and glutamic acid which make together 74% of all amino acid residues. The protein has a cationic character with an isoelectric point of 8.2. No carbohydrate component was found in this protein. The significance of arginine-rich basic protein in the cytoplasma of Guerin epithelioma is discussed briefly.

Amino Acids↗
PubMed1976

Participation of thyroid D-aspartate oxidase in iodide oxidation and incorporation into thyroid proteins.

It was found that the H2O2 generating system containing D-aspartate oxidase isolated from the thyroid gland and D-aspartate, takes part in oxidation of iodides. The molecular I2 formed under experimental conditions is subsequently incorporated into thyroid proteins. Thiosemicarbazide, thiourea, methylthiouracyl, sulphathiazole, thiocyanate and azides were found to have an inhibiting effect on iodide oxidation. Methimazole inhibits both the oxidation of iodide and incorporation of 131I into protein. The iodide incorporation was inhibited by catalase. The findings of these investigations suggest an indirect participation of D-aspartate oxidase in the synthesis of the thyroid hormone by supplying the essential substrate for the iodide oxidation, H2O2.

Amino Acid Oxidoreductases↗
PubMed1976

The comparison of aminotransferase activities in normal and Guerin epithelioma bearing rats.

The activities of 13 aminotransferawes in Guerin epithelioma and in the liver of normal and tumor bearing rats were investigated. Alanine and aspartate aminotransferases show the highest activity in all investigated tissues. In the liver of normal rats high arginine, tyrosine and phenylalanine aminotransferase activities were found. In tumor tissue high level of branched chain amino acid (leucine, valine and isoleucine) aminotransferases were observed. Increase in aminotransferase activities in the liver of tumor bearing rats was found. In order to elucidate the mechanism of this increase an inductive effect of hydrocortisone and protein free extract of tumor tissue on liver aminotransferases has been investigated. The tumor extract did not exert an inductive action. An inductive effect of hydrocortisone was not identical with the change in aminotransferase activities observed in the liver of tumor bearing rats.

Alanine Transaminase↗
PubMed1975

Insoluble collagen of methylcholanthrene induced sarcoma.

The insoluble collagen from methylcholanthrene induced sarcoma was isolated and characterized. It contains more glycine, hydroxyproline and acidic amino acids than normal connective tissue collagen. An anionic character of tumour collagen was stated (pI 6.1). No typical collagen subunits in this protein were found. The tumour collagen is strongly bound to acidic glycoprotein containing a significant amount of hydroxylysine. Such an insoluble complex is resistant to the dispersing action of EDTA. It dissociates during heating in concentrated urea.

Adenine↗