BENZALKONIUM CHLORIDE INHIBITED THE HISTAMINE-RELEASE FROM RAT PERITONEAL MAST-CELLS INDUCED BY BRADYKININ AND GLCNAC OLIGOMER-SPECIFIC LECTIN DATURA-STRAMONIUM AGGLUTININ, BUT HEPARIN DID NOT

1. Benzalkonium chloride (BAC) inhibited the histamine release from ra t peritoneal mast cells induced by synthetic cationic polymers (compou nd 48/80 and PEI(6)), bradykinin, des-Arg(1)-bradykinin and des-Arg(9) -bradykinin and Datura stramonium agglutinin (DSA). 2. The anionic pol ymers heparin, de-N-sulfated heparin, poly aspartic acid and poly glut amic acid dose dependently inhibited the histamine release induced by cationic polymers, suggesting counteraction between anions and cations . 3. Inhibition by heparin was diminished but that of BAC remained aft er removal of extracellular heparin and BAC. 4. Mast cell activation b y bradykinin and DSA was not inhibited by anionic polymers, suggesting that both bradykinin and DSA recognize membrane sites as receptors.