Requirement of cytoplasmic components for lidocaine-induced shape change in human erythrocytes.

To clarify the mechanism underlying local anesthetic-induced changes in the shape of human erythrocytes from discocytes to stomatocytes, we treated erythrocytes with lidocaine, a cationic drug. Analysis of the erythrocyte membrane and cytoplasm by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the intensities of the stained bands of 62 kDa, 28 kDa and 22 kDa depended on the extent of the shape change induced by lidocaine. The change in the intensity of the 28 kDa band was particularly marked. We identified the cytoplasmic substances, i.e., the 28 kDa and 22 kDa peptides, as carbonic anhydrase (CA) and glutathione peroxidase (GSH Px)1, respectively, by immunoblotting. The 62 kDa peptide was identified as Hb by column chromatography and SDS-PAGE analysis. To identify the protein responsible for the lidocaine-induced shape change, we incorporated CA and GSH Px into ATP-MgCl2-resealed ghosts. The shape of the resealed ghosts changed upon addition of lidocaine, but only in the presence of CA. These results suggest that ATP and CA are required for the shape changes induced by lidocaine.