[Lipid peroxidation and parameters of thermodenaturation of chromatin fractions in the rat liver]

Abstract

The fractions of transcriptionally active and repressed chromatin of the rat liver include lipids, whose fatty acid residues are the substrates of lipid peroxidation (LP) processes. In vitro incubation in NADPH- and ascorbate-dependent LP systems resulted in the activation of peroxidation in the liver chromatin of intact animals, estimated from malonic dialdehyde (MDA) accumulation, the LP processes proceeding more intensely in the fractions of transcriptionally active vs. repressed chromatin. This correlates with the content of LP substrates in these fractions. Single administration of tetrachloromethane stimulated LP (estimated from the content of diene conjugates) in the fraction of transcriptionally active chromatin. The intensity of MDA accumulation increased in the repressed chromatin fraction of animals with stimulated LP vs. the control. In animals with stimulated LP the changes in the thermodenaturation parameters of chromatin fractions were observed, being more expressed in the transcriptionally active fraction. In view of the temporal coincidence of the LP intensification in chromatin and of its structural-functional reconstruction, the alteration of intensity of LP processes in chromatin may be considered as a factor of regulation of functional activity of the genome.