[The effect of irradiation and alkylating agents on chromatin breakdown in normal and malignant lymphoid cells]. 
Regularities of chromatin degradation in thymocytes and LS/BL tumor cells have been investigated.  It has been shown that the rate of DNA degradation by Ca/Mg-dependent endonuclease in LS/BL tumor cells is 25 times lower than that in thymocytes, and radiation does not induce chromatin degradation.  The alkylating agent TS 160 causes chromatin degradation in both LS/BL cells and thymocytes.  In contrast to radiation TS 160 inhibits the endogenous chromatin degradation by Ca/Mg-dependent endonuclease in thymocytes.