Mucosal responses evoked by stimulation of ganglion cell somas in the submucosal plexus of the guinea-pig ileum.

The effects of electrical field stimulation and tetrodotoxin on the mucosal secretory response were compared in guinea-pig ileal mucosa with and without the submucosal plexus. Short-circuit currents and transmural electrical potential differences were similar in ganglionated and aganglionated tissues. Total tissue conductance was greater after removal of the submucosal ganglia. Electrical field stimulation evoked a tetrodotoxin-sensitive increase in short-circuit current in ganglionated tissues, and little or no response in aganglionated tissues. Both ganglionated and aganglionated tissues responded similarly to carbachol, vasoactive intestinal polypeptide, scorpion venom and alanine. These results suggest that electrical field stimulation of guinea-pig ileum evokes an increase in short-circuit current that reflects chloride secretion by exciting ganglion cell bodies whose axons project to the transporting cells and/or endocrine cells. Direct electrical activation of enteroendocrine cells is not a factor in the stimulus-evoked secretory response.