Figure 4

IgE causes sustained increase on specific anaphylactic reaction. ( A ) Effect of IgE on anaphylactic reaction. C57BL/6J mice were i.v. administered with discrete amounts of monomeric IgE directed against DNP-HSA. Twenty four hours later, antigen (100 μg) in 100 μl of Evans blue dye was i.v. injected and twenty minutes later, a passive cutaneous anaphylaxis assay was performed. A₆₂₀ represents the absorbance at 620 nm of the extravasation dye in the limbs. Results are shown as the mean ± SEM (n = 4-10). ( B ) Time-course of specific passive cutaneous anaphylaxis after a single administration of IgE. C57BL/6J mice were i.v. administered with monomeric IgE directed against DNP-HSA (750 ng), antigen was i.v. injected in Evans blue dye at days 1, 7, 14, 21 and 28 after sensitization with IgE. Twenty minutes later, a passive cutaneous anaphylaxis assay was performed. Results are shown as the mean ± SEM (n = 7-10). *, P < 0.05 versus 0 ng of IgE; &, P < 0.05 versus vehicle.