Cyanide Stimulation of Tri-N-Butyltin Mediated Hemolysis

摘要

The effects of tributyltin and sodium cyanide on hemolysis in human erythrocytes are described. Tributyltin has a sharp cut-off concentration for induction of hemolysis. A 5 micromole concentration of tributyltin induces hemolysis and mircromole less does not in erythrocyte suspensions with cells per ml. The kinetics for tributyltin-induced hemolysis are sigmoidal indicating a complex molecular mechanism leading to lysis. Ten mM sodium cyanide plus 1 micromole tributyltin does not stimulate hemolysis rates above levels observed with 10 mM sodium cyanide alone. Five mM sodium cyanide plus hemolytic concentrations of tributyltin stimulates hemolysis rates synergistically compared either cyanide or tributyltin alone. Ultrastructurally, hemolytic concentrations of tributyltin can be visualized in the electron microscope by osmium staining during fixation as electron-dense spheres penetrating the lip bilayer of the erythrocyte plasma membrane. Ten mM sodium cyanide plus 25 micromoles tributylin increases slightly the size of osmiophilic structures in erythrocyte membranes compared with those spheres seen in cells exposed to 25 micromole tributyltin alone. Sodium cyanide is the only compound tested that stimulates tributyltin-induced hemolysis.