CL-35 NMR-STUDY OF CL- DISTRIBUTION AND TRANSPORT IN HUMAN RED-BLOOD-CELL SUSPENSIONS

The chloride (Cl-) distribution in human red blood cell (RBC) suspensi ons was studied using cobalt(II) glycine, [Co(Gly)(3)](-), as a shift reagent (SR). When [Co(Gly)(3)](-) was added to suspensions of human R BCs, it shifted the Cl-35 NMR signal of the extracellular Cl-, Intrace llular and extracellular Cl-35(-) signals were clearly discriminated. Erythrocytes were impermeable to [Co(Gly)(3)](-) but were slowly perme able to the SR Co2+ and to the relaxation agent Mn2+. The exchange of intracellular Cl- with extracellular hypophosphite in human RBCs was m onitored by Cl-35 NMR. The Cl- efflux was found to follow first-order kinetics with an efflux rate constant of 0.0024 min(-1).