1979 年 99 巻 1 号 p. 8-13
Many of the amphipathic drugs tested, which induced shape changes in intact human erythrocytes, produced biphasic effects on hypotonic hemolysis of cells in a similar concentration range, protection at low concentrations and stimulation at higher concentrations. Both the exvaginators and invaginators, which induced shape changes of the membrane exvagination and invagination type, respectively, showed the same type of effect on osmotic resistance. When two drugs of either the exvaginator or invaginator type are present together in a hemolyzing medium, their effects on osmotic resistance appeared to be additive, as was the case with their effects on cell shape. In contrast, when an exvaginator and an invaginator are present together, their effects, both on osmotic resistance and cell shape, seemed to be antagonistic. The present results suggest that these drug effects may be caused, at least partly, by an asymmetric expansion of the membrane lipid bilayer due to asymmetric distribution of the drugs incorporated into the membrane.