Cation exchanger properties of isolated rat peritoneal mast cell granules

The synthetic carboxylic cation exchanger resin Amberlite IRC-50 was charged with histamine by suspension in histamine-containing solution with admixture of [14C]histamine. Mast cell granules were isolated from mast cells suspended in isotonic sucrose. The release of histamine induced from the two materials by superfusion with isotonic NaCl and KCL solutions showed identical kinetics, in accordance with the view that the release of histamine is due to a cation exchange: Na+ (K+) in equilibrium Hi+ at carboxyl groups in the granule heparin-protein complex.