Tumour localisation of gallium in relation to DNA synthesis, transferrin and lysosomal enzyme activity

Gallium-67, administered as a carrier-free citrate complex, has been widely used as a tumour localizing agent although it is not tumour-specific. The reasons underlying differential uptake of gallium-67 in tumours are not yet completely understood. Factors suggested to be important in the tumour uptake of gallium-67 are the rate of DNA synthesis, complexing by transferrin, fixation in lysosomes, and cell membrane permeability. These factors are discussed extensively on the basis of results from experiments by the authors. (G.H.)