Immunoglobulin E-mediated anaphylaxis activates nuclear factor κB in rat small intestine

Objective and Design: Since IgE-dependent reactions induce the inducible isoform of NO synthase, we postulated the involvement of the transcription factor NF-κB.¶Materials: 72 Wistar rats were divided into 6 groups and used to study the hemorrhagic necrosis of the small intestine elicited by anaphylaxis.¶Treatment: Passive anaphylaxis was produced by i.p. sensitization with IgE anti-dinitrophenyl monoclonal antibody and i.v. challenge with the cognate antigen.¶Methods: Competitive PCR was used to assay the expression of p50 subunit of NF-κB. κB-binding activity was assayed by electrophoretic mobility shift assay.¶Results: The PCR assay showed a time-dependent increase of mRNA coding for the p50 subunit of NF-κB, which was maximal 1 h after challenge (40 ± 3, versus 230 ± 32 f M, mean ± SEM) and decreased to prechallenge level at 4 h. κB-binding activity was also increased.¶Conclusions: IgE-mediated reactions trigger a pathway for nuclear signaling that seems to be related to the intermediate/late response of the allergic reaction.