The effect of prostaglandins E1 and E2 on the human erythrocyte as monitored by spin labels

Abstract The effects of the prostaglandins PGE 1 and PGE 2 on the deformability of the human erythrocyte were studied using spin-labeled erythrocytes. Two magnetic resonance parameters were measured: (1) The orientation relaxation time, t 1 2 , for the erythrocyte, and (2) the order parameter, S, for a fatty acid spin label bound to the membrane. Prostaglandins PGE 1 and PGE 2 exhibited opposite effects on both t 1 2 and S. PGE 2 made the cell less deformable (increases of t 1 2 and S) and PGE 1 made the erythrocyte more deformable (decrease of t 1 2 and S).