The influence of dimethylsulfoxide on the red cell membrane

Dimethylsulfoxide protects human red blood cells against haemolysis. This protection is caused by a drug-induced increase of the critical volume of the cells. Protection is abolished, when the cells are preincubated with dimethylsulfoxide in isotonic NaCl. Dimethylsulfoxide-induced K⁺ loss from red blood cells appeared to depend on the red cell volume. Presumably this phenomenon is related to volume dependent conformation changes at the cell surface, as described in recent literature. Further, dimethylsulfoxide causes a strong decrease of the red blood cell deformability, reflecting its profound influence on the physico-chemical properties of biomembranes. This effect also depends on the red cell volume. The results indicate that dimethylsulfoxide has similar effects on biomembranes as a wide variety of anesthetics. The effects of these anesthetics on biomembranes are usually attributed to a hydrophobic interaction with the membrane. It is shown, however, that a different interpretation of the results is also possible.