Non-enzymatic lipid peroxidation of rat liver nuclei and chromatin fractions.
In the study reported here, the non-enzymatic (ascorbate-Fe2+) lipid peroxidation of rat liver nuclei and chromatin fractions was assayed. Chromatin obtained by sonication of nuclei suspended in 0.25 M sucrose was fractionated by differential sedimentation according to the following scheme: 3000, 12,000 and 27,500 g for 10 min each. The lowest density chromatin fraction was obtained by precipitation with cold ethanol of the supernatant obtained from the last centrifugation. Light emission = chemiluminescence, measured as cpm/mg protein, decreased in the order heavy > low density chromatin fractions during the peroxidation process. Analysis of fatty acids by gas chromatography showed that heavy density chromatin fractions are enriched with C20:4 n6 arachidonic acid, when compared with low density chromatin fractions. The amount of arachidonic acid C20:4 n6 was higher in repressed chromatin fractions as compared to the amount in the transcriptionally active chromatin which correlates with the level of lipid peroxidation.
Marmunti
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M
Cátedra de Bioquímica, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Argentina.
Catalá
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D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism; D066298:In Vitro Techniques; D015227:Lipid Peroxidation; D008099:Liver / Q000378:metabolism*; D008163:Luminescent Measurements; D010743:Phospholipids / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D002843:Chromatin; D005227:Fatty Acids; D010743:Phospholipids; D011506:Proteins; D004247:DNA