[Polymorphism of a tumor ce-l population and selection processes. IV. The effect of dibunol and nitrosourea on the variability of Ehrlich-I. Ch. Ph. ascitic strain tumor cells].

A study was made of the effect of dibunol and methyl-N-nitrosourea (MNU) on two tumor cell subpopulations of the Ehrlich-I. Ch. Ph. ascites strain, one of which is characterized with A + B + 2C and A + D + 2C--markers and the other one--with A1 + A2 + 2B + D + C markers. Dibunol that belongs to the class of inhibitors of free-radical processes was shown to bring about changes in cell subpopulations, the mode of changes depending on the dose and regime of treatment. The effect of MNU on the population resulted predominantly in the accumulation of cells with various chromosome aberrations. At early stages of tumor progression, aberrations were more pronounced in cells with marker chromosome "A" than in the cells with 44 chromosomes and markers A1 + A2 + 2B + D + C.