METHYLMERCURY-INDUCED HEMOLYSIS AND BINDING OF THE MERCURY BY ERYTHROCYTE MEMBRANE

Binding of methylmercury by human erythrocyte membranes was examined in association with the mercury-induced hemolysis. Organic mercurials such as p-chloromercuribenzoate and methylmercury showed less potent hemolytic activity than HgCl2. Entry of methylmercury into the erythrocytes was very rapid. Over 95 % of methylmercury was taken up by the cells within 5 min over the concentration range studied. Percent binding by the membrane of methylmercury was lower than HgCl2. Affinity of the intact membranes as well as of the isolated membranes was found to be lower for methylmercury than for HgCl2. Analysis by means of the Scatchard plot indicated a variety of binding sites of the erythrocyte membranes for the mercurials. The critical level of methylmercury required for hemolysis was about 200 nmole/mg membrane protein. No close correlation was observed between membrane sulfhydryl inhibition and hemolysis. The results presented here suggested that affinity of the erythrocyte membranes for the mercuials is one of the determining factors in hemolysis.