Abstract
The development of allergic reactivity and the effect of disodium cromoglycate (DSCG) on that development were studied in groups of actively sensitized guinea pigs using both ocular sensitivity and antigen-induced histamine release from chopped lung, as test systems. DSCG reduced the allergic reactivity of animals actively sensitized for less than 12 days. At 12 days, DSCG was either inactive or it increased the reactivity of the animals. Antisera raised in animals co-immunized with Bordetella pertussis organisms were found to have a mixture of both IgE-like and γ1-like homocytotropic antibody properties. Passive cutaneous anaphylaxis (PCA) mediated by the IgE-like antibody was maximal at 48 h, was sensitive to heat and mercaptoethanol and was inhibited by DSCG. PCA mediated by γ1-like antibody was maximal at 4 h, was heat-stable, insensitive to 2-mercaptoethanol and DSCG and was apparently inhibited by concurrent stimulation of the IgE-mediated pathway.