Interaction of amphipathic drugs with erythrocytes from various species

Changes in morphology of human erythrocytes exposed to certain amphipathic drugs can be predicted by the bilayer couple hypothesis as proposed by Sheetz and Singer (Proc Natl Acad Sci USA 71:4456-4461, 1975). When we tested that hypothesis, using erythrocytes from other mammals, we found that most but not all, underwent the predicted changes. Both camel and llama erythrocytes showed minimal morphologic changes when exposed to anionic and cationic phenothiazines. The spicules formed by anionic drug in different species were numerically related to cell sizes. We conclude that structural rigidity of the erythrocyte membrane can alter the response predicted by the bilayer couple hypothesis.