Histamine hypersensitivity in mice induced by concanavalin A

This study compared the responses of CFW and CFI mice to concanavalin A (con A) and the histamine-sensitizing factor (HSF) of Bordetella pertussis. There were marked similarities between these two agents with regard to systems implicated in induced histamine sensitivity. Con A, like HSF, induces the sensitivity in CFW but not in CFI mice. The sensitizing agents both require the same time for optimum sensitization, both induce cutaneous sensitivities to histamine, and the mice are protected from the induced susceptibility of both agents by epinephrine and by desensitization with serotonin. They differed in that con A did not induce the systemic susceptibility to serotonin or to combined histamine and serotonin which is produced by HSF. The major difference related to mechanisms of action was the failure of con A to induce a systemic beta-adrenergic blockade, the block of which is manifested in HSF-treated CFW and CFI mice by the inhibition of an epinephrine-induced hyperglycemia. The resistance of beta-blocked CFI mice to histamine, and the susceptibility to histamine of the unblocked CFW mice sensitized with con A, is inconsistent with the theory that susceptibility results from a systemic adrenergic imbalance, but does not preclude a local adrenergic effect as the common element in histamine-sensitizing agents.