Dissociation of the immunologic release of histamine and slow reacting substance of anaphylaxis from human lung using cytochalasins A and B-1.

Cytochalasins A and B at low doses resulted in enhancement of the antigen-induced and anti-IgE-mediated release of histamine from human lung fragments in vitro. Both compounds appeared to effect a dose-dependent inhibition of the antigen-induced release of slow reacting substance of anaphylaxis. Although the effects observed with cytochalasin B were at least partially reversible, the effects of cytochalasin A could not be readily reversed. The cytochalasins appeared to be more effective when present during the antigen-dependent activation phase of mediator release rather than during the calcium-dependent release phase.