Mechanisms of selective uptake of 2-methyl-4-naphthoquinol bis disodium phosphate, into some mammalian cells in tissue culture.

Earlier papers have described the selective uptake of the radioactive drug 2-methyl 6,7-ditritio-1, 4-naphthoquinol bis disodium phosphate into some human tumour cells in tissue culture. This work examines these results in greater detail. The kinetics of the uptake process into HEp/2 cells and its precise dependence on the experimental conditions are described. It is shown that an alkaline phosphatase (APase) is present on the surface of HEp/2 cells and that this is responsible for the uptake of label. L cells do not take up the radioactive label and are shown not to possess significant quantities of APase.