The dynamics and periodicity of LPO processes in the nuclei and chromatin were detected during regenerative processes in mouse liver. LPO processes were enhanced in transcriptionally active and replicating chromatin. Phosphatidylcholine, phosphatidylinositol, esterified cholesterol, and free fatty acids were maximally oxidized during active transcription, and cardiolipin was oxidized during active replication. These processes were accompanied by periodical changes in activity of antioxidant enzymes. High activity of SOD during transcriptional activity of liver cells was typical for nuclear matrix-attached chromatin, but this parameter decreased during replication. Catalase activity signifi cantly increased in the fractions of highsalt chromatin and nuclear matrix-bound chromatin during replication.

The qualitative and quantitative differences in lipids composition were found in chromatin fractions differing by attachment to the nuclear matrix and transcriptional activity. During liver regeneration after partial hepatectomy Changes in the lipid spectrum of chromatin fractions in G(1)- and S-phases are associated with transcriptional activity and their primary involvement in replication.