Changes in the proliferation characteristics of a solid transplantable tumour of the mouse with time after transplantation.

The aim of the present investigation was to study changes in cell proliferation kinetics with time after transplantation in a solid transplantable mammary carcinoma of the C3H mouse. From growth curves and tumour doubling times, three different experimental times were chosen; the exponential phase of growth on the 7th day post-transplantation, during the phase of retardation on the 21st day after transplantation and in the stationary phase of growth on the 30th day after transplantation. It was found that the cell loss factor contributed primarily to the retardation of volume growth. The lowering of the growth fraction played a minor part in the delay of growth while the duration of cell cycle was not prolonged before the plateau phase of growth on the 30th day after transplantation was reached.