SUBMANDIBULAR-GLAND PEPTIDE-T (SGP-T) INHIBITS INTESTINAL ANAPHYLAXIS

A novel peptide, submandibular gland peptide-T (SGP-T), which reduces allergen-induced hypotension, was examined for effects oh intestinal a naphylaxis. Hooded-Lister rats were sensitized to egg albumin and prep ared for the measurement of in vivo myoelectric activity of the jejunu m. The disruption of migrating myoelectric complexes (MMCs) that occur s upon intraluminal, duodenal challenge with antigen of sensitized rat s was inhibited by 75% upon intravenous treatment with 100 mu g/kg of SGP-T. In addition, SGP-T reduced the number of rats experiencing anap hylactic diarrhea and disrupted MMCs, but the peptide did not alter an tigen-provoked release of rat mast cell protease II. The mechanism of action of SGP-T remains to be determined, but it apparently does not a ct directly on mast cells to exert its antianaphylactic action. These results emphasize that modulation of immediate hypersensitivity reacti ons is only one of several gastrointestinal activities that are affect ed by growth factors and peptides released from salivary glands.