Bee Venom-Induced Shrinkage of Erythrocyte Ghosts

S. V. Rudenko,^1,2 G. A. Bojok,¹ and E. E. Nipot¹

¹Institute for Problems of Cryobiology and Cryomedicine, National Academy of Sciences of the Ukraine, ul. Pereyaslavskaya 23, Kharkov, 310015 Ukraine; fax: (0572) 72-00-84; E-mail: cbi@ilt.kharkov.ua

²To whom correspondence should be addressed.

Submitted April 19, 1996; revision submitted November 4, 1996.

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.

KEY WORDS: erythrocytes, bee venom, melittin, phospholipase A₂, hemolysis, divalent cations, chlorpromazine.

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