The physical chemistry of haemolysis by surface-active agents

Abstract

The surface tensions of solns. of non-ionic, anionic and cationic reagents and their penetration of cholesterol monolayers were measured. Lysis appears to depend on the production of a lowering of interfacial tension corresponding to about 34 dynes/cm, at an air-water interface. This lowering is produced by non-ionic detergents at concns. at which they give surface pressures greater than 34 dynes/cm, and by ionic detergents at concns. at which they produce the pressure by penetration of a cholesterol monolayer. Mixtures of cationic and anionic detergents behave like non-ionic reagents. There is a lysis reactivity series with the ionic detergents analogous to their association with cholesterol monolayers. The findings are consistent with the view that hemolysis is duet to the collapse of a cholesterol phospholipin-lipoprotein complex, the cholesterol being the site of attack of saponin and ionic detergents.