Sensitivity of passive cutaneous anaphylaxis in rats. I. Inverse relationship between PCA sensitivity and amount of IgE present on mast cells.

Passive cutaneous anaphylaxis (PCA) sensitivity and IgE antibody production were examined in rats from four different outbred colonies: Wistar A, Wistar B, Sprague-Dawley, and Donryu. PCA sensitivity was the highest in Wistar B and the lowest in Wistar A rats using anti-Ascaris, antibovine serum albumin, and anti-Clonorchis sinensis IgE antibodies. The PCA sensitivity related inversely to the reverse PCA reaction with rabbit antirat IgE antibody, suggesting that preexisting IgE molecules on the mast cells in the skin interfered with the PCA reaction. However, the skin sensitivity to compound 48/80 was comparable in rats from the four colonies indicating the same sensitivity to nonimmunological stimulation. Ability of rats to produce IgE antibody was tested by immunizing them with dinitrophenol-coupled Ascaris extract and Bordetella pertussis adjuvant. Essentially no difference in antidinitrophenol-coupled Ascaris extract IgE antibody production was observed among animals from the different colonies.