Bee venom-induced shrinkage of erythrocyte ghosts

When hemolysis of erythrocyte ghosts is induced by bee venom, their volume becomes significantly less than the initial volume of the cells. Treating isolated ghost membranes with bee venom has the same effect. An analogous phenomenon is caused by a mixture of purified melittin and phospholipase A2, but not by the separate action of these substances. The volume changes develop non-monotonously in time. A prolonged phase of spontaneous volume restoration follows the initial phase of shrinkage. Inhibitors of melittin-induced hemolysis (Mg2+, chlorpromazine) retarded the development of both shrinkage and restoration phases, but did not influence the extent of the volume changes. High concentrations of Ca2+ (10 mM) acted in a similar manner, but increased the extent of shrinkage at low concentration (0.1 mM). The extent of shrinkage was increased several-fold in isotonic nonelectrolyte solutions. Analysis of the data shows that bee venom-induced reduction in ghost volume is not due to osmotic effects or permeabilization and/or fragmentation of the membrane, but rather is attributed to membrane contraction, which presumably relates to the membrane cytoskeleton. In this respect venom-induced shrinkage resembles that of contractile events in non-muscle cells.