pH effects on red cell deformability.

The effect of pH on erythrocyte deformability was determined in the ektacytometer. In isotonic solutions, cell deformability was essentially unaltered at pH values from 6.44 to 7.7, despite the known cell volume changes that occur over this pH range. Analysis by osmotic scan ektacytometry showed that erythrocyte deformability is homeostatically maintained constant during acidosis and alkalosis because of a balance between the countervailing effects of changes in intracellular viscosity and in the surface to volume ratio. This balance is perturbed in the sickle erythrocyte, so that acidosis improves deformability.