[The effect of Zn ions on erythrocyte hemolysis induced by melittin].

Divalent cations--Ca2+ and Zn(2+)--were shown to produce inhibition of melittin-induced hemolysis of erythrocytes in the hemolysis phase, the degree of blocking increasing with a rise in the cation concentration. Besides, Zn2+ ions altered, in a concentration-dependent manner, the initial stages of interaction between melittin and red cell membranes, resulting in a slowdown of the melittin insertion and hemolysis rate. A comparison of dependencies between the hemolysis rate and melittin and cells concentrations in the medium as well as the regularities of the blocking activity of cations under various conditions with the corresponding data concerning melittin-induced lysis of lipid vesicles indicates that melittin-induced hemolysis and lysis of lipid vesicles have little in common, thus being suggestive of an insignificant role of melittin-lipid interactions in the mechanism of cell hemolysis. The data obtained provide evidence that the erythrocyte membrane contains an intrinsic blocking mechanism whose efficacy can be synergistically enhanced by Zn2+ ions protecting the cells against the lytic effect of melittin.