Arrest patterns of circulating lymphosarcoma cells in tumour-bearing mice as modified by previously injected cell suspensions.

The effects were determined of an initial i.v. injection of 0.2 ml suspensions of 125IUdR-labelled lymphosarcoma cells on the early arrest patterns of a second injection of cancer cells into tumour-bearing mice. The results indicate that interactions between the first injection and the host markedly affected the arrest pattern of the second dose in the lungs, but not the livers, of tumour-bearing animals. These observations are explained on the basis of the injected fluid volumes, which are considerable in mice, in relation to their total blood volumes of approximately 2 ml.