Radiolabeling of erythrocytes with technetium-99m: role of band-3 protein in the transport of pertechnetate across the cell membrane.

This study analyzes the transport characteristics of the pertechnetate anion across membranes of human erythrocytes during labeling with technetium-99m (99mTc). Transport of this anion is inhibited after incubation at low temperature, indicating the involvement of a process with high activation energy. Transport is also decreased by two well-known inhibitors of the band-3 anion transport system and is not affected by inhibition of the Na/K/Cl co-transport system. From these results we conclude that, in the process of labeling red blood cells with 99mTc, the pertechnetate anion may reach the interior of the erythrocyte through the band-3 anion transport system.