INTESTINAL MYOELECTRIC RESPONSE IN 2 DIFFERENT MODELS OF ACUTE ENTERIC INFLAMMATION

The inflammatory responses to intraluminal administration of the cytot oxic lectin ricin or the hapten 2,4,6-trinitrobenzenesulfonic acid in 25% ethanol were compared. Myoelectric activity was recorded from in v ivo ileal loops in rabbits after administration of either agent. At th e end of a 6-h study the loops were removed and prepared for histologi cal evaluation and for ex vivo generation of leukotriene (LT) C-4 and prostaglandin (PG) E(2). Both agents induced significant increases in mucosal damage, polymorphonuclear leukocyte infiltration, and edema. T hese changes tended to be patchy in the hapten model and confluent in the ricin model. Spike burst activity and mucosal LTC(4) and PGE(2) ge neration were also enhanced significantly. Intraluminal administration of the specific LTD(4) antagonist Wy-48252 1 h before either inflamma gen, significantly inhibited the myoelectric response without affectin g tissue morphology or eicosanoid synthesis. These data demonstrate th at there is a stereotypic spike burst response to acute inflammation, which is mediated in part by LTD(4).