Abstract
An investigation on the effect of heparin on leukocytes in vitro was conducted. We have demonstrated that heparin and other mucopolysaccharides destroyed leukocytes as judged by macromolecule leakage. The cytotoxicity of heparin was suppressed by protamine. A medium which mimics intracellular ionic conditions was found to suppress the cytotoxicity of heparin. Macromolecule leakage induced by heparin is thought to be facilitated by passive ion flux. Mepacrine, a phospholipase inhibitor, suppressed the heparin-induced macromolecule leakage from leukocytes. Thus, the activation of phospholipase appears to be involved in the cytotoxicity of heparin. These results suggest that activation of phospholipase and passive movement of ions may be important steps for the heparin-induced leukocyte lysis in vitro.
