Cell population kinetics in the intestinal epithelium of the mouse

Abstract

The kinetics of cell proliferation and movement were studied in a comparatively simple system, the intestinal epithelium of the mouse. The methods used included differential cell counts (including mitosis counts) and high resolution autoradiography after labeling with tritiated thymidine. The latter method allows the identification of those cells which were synthesizing DNA at the time the label was administered. By varying the interval between labeling and sacrifice, one can locate the sites of cell production, and follow the course of cell migration. By counting labeled and unlabeled mitoses in animals sacrificed various times after labeling, one can reconstruct the kinetics of the proliferative cycle. Using the experimental data so obtained together with a simple scheme of kinetic analysis, an analysis of the steady-state kinetics for all phases of cell life so far known (in this tissue) was made. In addition, it was found that the only conspicuous process of cell differentiation which occurs in this tissue is linked to a particular phase of the proliferative cycle.