The regulatory effect of histamine on the in vitro synthesis of IgE.

The effect of histamine and its H1 and H2 antagonists, chlorpheniramine and cimetidine, on the in vitro, PWM-induced, synthesis of IgG and IgE was studied. Histamine had no effect, and cimetidine had a slight inhibitory action. In contrast, chlorpheniramine induced marked suppression of both IgE and IgG synthesis. This effect could not be attributed to drug-induced cytotoxicity. These results suggest that the modulatory effect of histamine on antibody production involves predominantly H1 receptors.