Abstract
After treatment of human erythrocytes at 37°C with a cationic amphiphilic drug (one of various tertiary amine phenothiazines, primaquine or n-decylamine), up to 45% of the membrane phosphatidylethanolamine (PE) was degraded by added phospholipase A2 from bee venom (untreated erythrocytes, 1-2%) and about 35% of the PE could be labelled by trinitrobenzenesulfonate (untreated erythrocytes, about 14%). Pancreatic phospholipase A2, which is virtually unable to hydrolyze the phospholipids of intact erythrocytes, degraded significant amounts of phosphatidylcholine and PE in the erythrocyte membrane pretreated with the above drugs. These results suggest that cationic drugs in general may alter the protein-lipid interaction of the membrane and thus release the inner layer phospholipid PE from possible locational restriction under the influence of certain proteins.
