Uptake of 51Cr(VI) by human erythrocytes: evidence for a carrier-mediated transport mechanism.

Uptake of 20 micron 51Cr(VI) by resuspended red blood cells (RBC) (0.9% saline) was studied. Inhibition of the specific anion carrier system "band-3-protein" of RBC membrane with "SITS" (4-acetamido-4'-cyanatostilbene-2,2'-disulphonic acid) resulted in a non-competitive type of inhibition for chromium uptake. It is concluded that Cr(VI) is transported by participation with this system. Intracellularly, chromium is almost quantitatively bound to hemoglobin and trapped for the cell's lifetime. Glutathione (GSH) is possibly involved in this process as indicated by incubation experiments of RBC with 10 mM Na2(51)CrO4. In these experiments, a rapid decrease of GSH content of the cells was observed.