The effect of daunorubicin and glutaraldehyde treatment on the structure of erythrocyte membrane

The effect of daunorubicin (DNR) and glutaraldehyde on erythrocyte membrane structure was examined by Electron Spin Resonance spectroscopy. Human eryt hrocytes were incubated with daunorubicin and then with glutaraldehyde to p revent drug efflux. We have demonstrated that DNR alone caused changes in m embrane fluidity mainly in the hydrophobic regions of the lipid bilayer. Wh en DNR-preincubated erythrocytes were treated with glutaraldehyde, the alte rations in fluidity were observed in the polar regions as well as in the de eper regions of the cell membrane. The incorporation of drug and glutaralde hyde into human erythrocytes also caused conformational alterations in memb rane cytoskeletal proteins and changes in the internal viscosity of the cel ls. The results suggest that glutaraldehyde in the drug-pretreated erythroc ytes may lead to significant perturbations in the organization of the plasm a membrane lipids and proteins. (C) 1999 Published by Elsevier Science B.V. All rights reserved.