[A quantitative cytochemical study of mouse hepatocyte chromatin in the early periods following hepatectomy].

Mouse hepatocytes of different ploidy react to the partial hepatectomy by changes in cytochemical properties of the chromatin, leading to an increased binding to DNA of a basic dye acridine orange and an antibiotic actinomycin D, and to decreased DNP stability to acid hydrolysis. These alterations reach their maximum 1.5 and 2.5 hours after the operation in di-and tetraploid, and octaploid cells, resp. and decrease markedly by 5 hours after the operation. The differences in the chromatin reaction of cells with different ploidy to the activation stimulus reflects presumably the particular roles played by these cells in liver regeneration. The difference in chromatin cytochemical properties of activated and non-activated hepatocytes is interpreted as a result of changes in DNA interaction with chromatin proteins.