methyl-13-hydroperoxy-9-11-octadecadienoate and thiobarbituric-acid

The incubation with methyl linoleate hydroperoxides (MLHPO), a model of lipid peroxides, depressed DNA, RNA and protein syntheses of mouse thymic lymphocytes and increased the amount of thiobarbituric acid-reactive substances in lymphocytes. These phenomena were also found in the splenic lymphoblasts in the DNA synthetic phase (S-phase) obtained by mitogen. Prior culturing with all-rac-alpha-tocopherol increased DNA synthesis in splenic lymphoblasts. Electron microscopically, cytoplasmic micro-organelles of splenic lymphoblasts in the S- and G2-phases were markedly destroyed as compared with nuclei. No discernible changes were observed in not-blastotransformed lymphocytes under these experimental conditions. These findings indicate that thymic lymphocytes and splenic lymphoblasts are affected by exogenous lipid peroxides, and cytoplasmic micro-organelles of splenic lymphoblasts might be markedly damaged by exogenous lipid peroxides as compared to their nuclei.

Topics: Animals; Cells, Cultured; DNA; Lipid Peroxides; Lymphocytes; Male; Mice; Mice, Inbred C57BL; Microscopy, Electron; Protein Biosynthesis; RNA; Spleen; Thiobarbiturates; Thymus Gland; Vitamin E

Formation of N-nitrosodimethylamine in chloroform or in mixtures of chloroform/citrate buffer or methyl stearate-chloroform (1:9)/citrate buffer was faster than that in citrate buffer alone. The chemically inert non-aqueous solvent may increase the level of the non-ionized active species of the nitrosating agent. The presence of unsaturated fatty acid methyl esters in chloroform suppressed formation of N-nitrosodimethylamine compared to that in chloroform alone but, because of the non-aqueous solvent effect, nitrosamine formation was slightly higher than that in citrate buffer. Fats containing unsaturated fatty acids also inhibited nitrosamine formation in chloroform indicating that the unsaturated fatty acid residues were effective scavengers of the nitrosating agent. Methyl linoleate was converted into peroxide(s) with carbonyl or carbonyl-liberating functions by reaction with nitrous acid, although it is not clear whether the reaction was relevant to the loss of nitrous acid.

Topics: Chemical Phenomena; Chemistry; Chloroform; Chromatography, Thin Layer; Dimethylnitrosamine; Fatty Acids, Unsaturated; Linoleic Acids; Lipid Peroxides; Nitrosamines; Nitrous Acid; Peroxides; Solvents; Thiobarbiturates

Topics: Animals; Antioxidants; Ascorbic Acid; Glutathione; In Vitro Techniques; Lipid Peroxides; Liver; Male; Rats; Rats, Inbred Strains; Thiobarbiturates; Vitamin E