[Endonucleolysis of chromatin in thymocytes of irradiated and non-irradiated rats].

It was shown that in conditions optimal for Ca/Mg endonuclease, chromatin endonucleolysis in the nuclei and thymocytes occurs due to internucleosome fragmentation of DNA. Irradiation activates chromatin degradation in thymocytes washed by a buffer containing 0.25 M sucrose, 10 mM tris-HCl, pH 7.2, 3 mM MgCl2, and does not influence this process in thymocytes washed by 10 mM tris-HCl, pH 7.2, 3 mM MgCl2.