Some biophysical properties of the erythrocyte membrane in Duchenne muscular dystrophy

Inasmuch as prior authors have suggested a 'generalized membrane defect' in patients with Duchenne muscular dystrophy, this study was undertaken to examine some biophysical properties of the erythrocytes in affected individuals. Using the micropipette technique we investigated the rheological properties of erythrocytes from 11 Duchenne muscular dystrophy patients (boys 3-14 years old) and 5 carriers (mothers 20-42 years old). The mean elastic modulus and membrane viscosity of the patient's erythrocytes were not significantly different from those of a group of 8 unaffected age-matched boys. The carrier group did not differ significantly from the adult control group in any of the rheological parameters. A significant increase in the number of stomatocytes was observed in the patient group, and a similar trend (not statistically significant) was observed in the carrier group. The membrane lipid fluidity of erythrocytes from patients, carriers, and normal controls was assessed with three different probes by fluorescence depolarization, and no significant differences were found. Our results indicate that there is a progressive elevation of the membrane elastic modulus with increasing age of the patients: the younger patients have a lower elastic modulus than their age-matched controls, while the older patients have a higher elastic modulus than their age-matched controls.