Effects of α-amanitine on chromatin in regenerating rat hepatocytes

Abstract

Almost all the chromatin in nuclei of regenerating rat liver hepatocytes 15 h and particularly 24 h after partial hepatectomy appeared as decondensed chromatin. Treatment with .alpha.-amanitin induced a clear condensation of decondensed chromatin as early as 30 min after toxin injection. The degree of condensation increased further until, 2 h after poisoning, almost all the chromatin was found to be in condensed form. Because DNA synthesis after toxin injection was not modified during the first 2 h and 30 min, the chromatin condensation probably did not affect DNA synthesis. The relationships between the inhibition of RNA synthesis and the chromatin ultrastructural changes are also discussed.