Membrane elastic shear modulus of red blood cells with glucose-6-phosphate dehydrogenase and pyruvatekinase enzymopathies.

The membrane elastic shear modulus mu determined by a micropipette technique was found to be elevated by 25% to 200% for red blood cells (RBC) from 7 patients with glucose-6-phosphate dehydrogenase (G-6-PD) and 9 patients with pyruvate-kinase (PK) enzymopathies above the mean value for normal controls. All patients exhibit chronic nonspherocytic hemolytic anemias. A negative linear correlation (r = -0.72) between mu and the number of reticulocytes was obtained in G-6-PD deficiencies. In contrast, a positive correlation (r = 0.88) was found for red blood cells of patients with PK deficiency. A mechanically induced swelling of RBC was observed for some deficient cells. The results are discussed in the framework of structural alterations of the RBC membrane due to the disturbed pentose-phosphate pathway and the diminished ATP supply through glycolysis, respectively.