A proton nuclear magnetic resonance study of the interaction of cadmium with human erythrocytes.

The binding of Cd2+ by molecules in the intracellular region of human erythrocytes has been studied by 1H-NMR spectroscopy. From changes in spin-echo Fourier transform NMR spectra for both intact and hemolyzed erythrocytes to which CdCl2 was added, direct evidence was obtained for the binding of Cd2+ by intracellular glutathione and hemoglobin. Time-courses were measured by 1H-NMR for the uptake of Cd2+ by intact erythrocytes in saline/glucose solution and in whole blood. In both cases, the uptake, as indicated by changes in the 1H-NMR spectrum for intracellular glutathione, plateaus after about 30 min. The effectiveness of the disodium salt of EDTA and of various thiol-chelating agents for releasing glutathione from its Cd2 + complexes in hemolyzed erythrocytes was also studied. EDTA was found to be more effective than thiols, and dithiols more effective than monothiols.