Phosphorus-31 and water proton relaxation in living erythrocytes. Application to uremia

We measured the spin-lattice and spin-spin relaxation times ( T 1 andT 2 , respectively) and the nuclear Overhauser effect (NOE) of 31 P nuclei of 2,3-diphosphoglycerate (2,3-DPG) in living erythrocytes. The relaxation of water protons was also studied. Phosphorus relaxation is pH-dependent due to a modification of the binding of 2,3-DPG to hemoglobin. We compared the results obtained with normal and uremic erythrocytes. In uremic erythrocytes the 31 P relaxation rates are increased, but the intraerythrocytic pH variation in uremic erythrocytes cannot itself explain this increase. A possible role of dialysable substances may explain the increased relaxation rate.