[The effect of monovalent cations on the structure of chromatin from Ehrlich ascites carcinoma cells]

Changes in the intracellular ratio of monovalent cations resulting in the alteration of transcriptional activity in some cell-specific genes have been investigated. It was found that at varying intracellular Na+/K+ concentration ratios the accessibility of the beta-actin gene to the effect of exogenous DNAaseI changes drastically. The use of hybridization of restricted DNA of the nuclear matrix with appropriate probes revealed that the number of copies for oncogenes c-fos and c-myc within this DNA changes with alteration of the intracellular ratio of monovalent cation concentrations.