Comparative Study of the Kinetics of Cellular Proliferation of Normal and Tumorous Tissues With the Use of Tritiated Thymidine. I. Dilution of the Label and Migration of Labeled Cells2

Abstract

The pattern of cellular proliferation of the Ehrlich tumor, the small intestine, and the liver of the adult mouse was studied in animals given injections of tritium-labeled thymidine. The dilution of the label and the migration of labeled cells at various intervals after the injection of tritiated thymidine were studied by radioautographic and radiochemical techniques. The results show that in the cells of the crypts of the small intestine the intensity of the label is diluted at a faster rate than in the Ehrlich tumor cells growing in the lungs. The results also show that, on the 4th day after the injection of tritiated thymidine, radioactive label is reutilized in large enough amounts to be detectable by the techniques used.