KINETICS OF CELL-PROLIFERATION IN A RAPIDLY GROWING MURINE LYMPHOSARCOMA

: The growth kinetics of a murine lymphosarcoma were investigated the spleen and liver of mice by means of quantitative flow-cytofluorometric DNA measurements in individual cells in combination with 3H-thymidine incorporation into the DNA. The amount of DNA in the S-phase cells was calculated from the resulting DNA histograms. From the 3H-thymidine incorporation, related to the amount of S-phase DNA, the relative changes in the duration of the S-phase during the growth of the lymphosarcoma were estimated. A marked prolongation of the duration of the S-phase was observed in the course of the growth of the lymphosarcoma. The disappearance of cells of higher ploidy normally found in the liver indicates the elimination of those normal cells in the course of the tumour growth.