Suppression by mepyramine maleate of the increased vascular permeability in passive cutaneous anaphylaxis in the chicken.

Passive cutaneous anaphylaxis was produced in chickens pretreated with the antihistamine mepyramine maleate. Quantitative estimation of the increased vascular permeability in the lesion revealed 79.5% suppression indicating its mediation largely by histamine. The findings suggest that the quantitative estimation of the increased vascular permeability, though time-consuming, is more precise than the visual assessment.