Basophil Activation by Concanavalin a: Characteristics of the Reaction

Abstract

Concanavalin A (Con A) induced histamine release from the basophils or mast cells of several mammalian species including human, rabbit guinea pig, mouse, and rat. The mechanism was investigated in detail in humans. Wide variation in the response of the basophil of different individuals was found. The optimum release was produced with 1 to 3 µg/ml of Con A. The response is characterized by inhibition by excess amounts of Con A and has great similarity to antigen activation of basophils. The release of histamine by Con A requires Ca²⁺, is modulated by the level of cyclic AMP, is inhibited by chlorphenesin and diethylcarbamazine and enhanced by deuterium oxide. The activation of the basophil depends on the binding of Con A to pyranosyl sugar residues on the cell membrane.