Inhibition of hemolysis by zinc and its reversal by L-histidine

Abstract
Hemolysis [of rat and sheep erythrocytes] induced by staphylococcal .alpha.-toxin, staphylococcal .beta.-toxin, streptolysin O and streptolysin S was inhibited by Zn2+ by virtue of inhibition of an early step in events leading to lysis, presumably by preventing lysins from attaching to the plasma membrane. In hemolysis induced by Clostridium perfringens .alpha.-toxin and by perfringolysin O, a later step was inhibited by Zn. In hemolysis caused by saponin, lysolecithin and Triton X-100, hemoglobin was precipitated by Zn2+ as it was released from the erythrocyte. Inhibition by Zn was abolished by several amino acids of which L-histidine was the most effective.