[Changes in the structure of Ehrlich tumor cell populations]

In late stages of Ehrlich tumor development there occurs a gradual increase of the portion of cells, being in the second half of the mitotic cycle, on account of cells of the initial stages of mitosis. Simultaneously, resting cells are accumulated. The data of energy metabolism may account for these changes in the population structure. Under conditions of the glucose deficiency accompanying tumor growth the ATP deficit proves to be greater in cells of the second half of the mitotic cycle than in cells of the beginning of mitosis, thus resulting in redistribution of cells with stages of the mitotic cycle. In an old tumor the rate of DNA synthesis was shown to be lower at all stages of S-phase, while RNA synthesis was mostly activated in cells of G-period. In S- and G2 cells of an old tumor the total protein content was reduced. In G0-cells nuclei of Ehrlich tumor electrophoresis in polyacrylamide gel would show protein with a molecular weight 9000 +/- 500, which was absent in proliferating cells nuclei. It was demonstrated that protein with analagous properties is contained in nuclei of 13 transplantable animal tumors.