[A DNA study of rat liver oligonucleosomes enriched by transcriptionally active genes during induction due to the administration of an amino acid mixture]. / Izuchenie DNK oligonukleosom pecheni krys, obogashchennykh transkriptsionno aktivnymi genami, pri induktsii, vyzvannoi vvedeniem smesi aminokislot.

A highly active fraction of rat liver oligonucleosome DNA has been isolated and studied by means of thermal denaturation after induction by amino acid mixture or hydrocortisone. A considerable redistribution of DNA content has been shown in sucrose gradient fractions during these forms of induction. The changes are revealed in melting temperature, differential melting profile of DNA, isolated from actively transcribed chromatine fractions. Analysis of melting profiles shows changes of GC content of oligonucleosome DNA, suggesting that there are differences in activation during two studied forms of induction.

[Physicochemical parameters of rat liver chromatin during nonhormonal induction]. / Izuchenie nekotorykh fiziko-khimicheskikh parametrov khromatina pecheni krys pri negormonal'noi induktsii.

The changes of RNA-polymerase activity of hepatocytes nuclei, chromatin circular dichroism (CD) spectra and differential melting curves of hepatocytes of rats which were injected hydrocortisone or amino acid mixture intraperitoneally have been studied. Actinomycin D reduces essentially RNA-polymerase activity and maximum of CD spectra. Under the influence of hydrocortisone or amino acid mixture the inhibiting action of antibiotic is taken off but the RNA-polymerase activity and maximum of CD spectra don't achieve the meanings found under the influence of inductors only. The antibiotic injection changes essentially the chromatin melting parameters. A conclusion has been drawn that the amino acid mixture and hydrocortisone effect the transcription process affecting the different levels of chromatin structure.