Effect of splanchnectomy on jejunal motility and Fos expression in brain stem after intestinal anaphylaxis in rat

This study was to determine whether alterations in jejunal motility observe d after antigen challenge of sensitized rats occurred after extirpation of the celiac-superior mesenteric ganglia. Hooded-Lister rats were prepared wi th an intact or extirpated celiac-superior mesenteric ganglion, an isolated Thiry-Vella loop of ileum for instillation of antigen, and jejunal electro des for myoelectric recording. Animals were sensitized by injection of 10 m ug egg albumin (EA, ip), and specific anti-EA IgE titers were determined to be >1:64. In both control and splanchnectomized rats, normal fasting migra ting myoelectric complexes (MMC) were observed before challenge with EA. MM Cs were disrupted, and diarrhea was observed immediately after EA challenge of control but not splanchnectomized animals. Brain stems were removed and processed for Fos immunoreactivity. The absence of perivascular neuropepti de Y immunoreactivity in the submucosa was used to confirm the success of s planchnectomy. The number of Fos-immunoreactive neuronal nuclei was signifi cantly reduced in the brain stem after splanchnectomy. Thus the mesenteric sympathetic ganglia are an integral part of the extramural neuronal pathway s required for altered motility in this model of intestinal anaphylaxis.