IMMUNOGLOBULIN E-MEDIATED ANAPHYLAXIS ACTIVATES NUCLEAR FACTOR KAPPA-B IN RAT SMALL-INTESTINE

Objecti ve and Design: Since IgE-dependent reactions induce the induci ble isoform of NO synthase, we postulated the involvement of the trans cription factor NF-kappa B. Materials: 72 Wistar rats were divided int o 6 groups and used to study the hemorrhagic necrosis of the small int estine elicited by anaphylaxis. Treatment: Passive anaphylaxis was pro duced by i.p. sensitization with IgE anti-dinitrophenyl monoclonal ant ibody and i.v. challenge with the cognate antigen. Methods: Competitiv e PCR was used to assay the expression of p50 subunit of NF-kappa B. k appa B-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-kappa B, which was maximal 1 h after challenge (40 +/- 3, versus 230 +/- 32 fM, mean +/-SEM) and decreased to prechallenge level at 4 h kappa B-binding activity was also increa sed. Conclusions: IgE-mediated reactions trigger a pathway for nuclear signaling that seems to be related to the intermediate/ late response of the allergic reaction.