[Nuclease sensitivity and methylation of chromatin DNA of the rat liver in the initial period of glucocorticoid activity].

Structure and function of liver chromatin of adrenalectomized rats 3.5 h after hydrocortisone administration were studied. It was shown that despite changes in chromatin function under hormonal action (transcription enhancement and DNA synthesis inhibition), the level of nuclear DNA methylation and its sensitivity to DNase 1 were not markedly changed. This means that hormone-activated genome loci originally possess DNase 1 sensitive "potentially active" conformation.