Open AccessEnterochromaffin cells of the digestive system: cellular source of guanylin, a guanylate cyclase-activating peptide.
Author(s) -
Yalcin Cetin,
Michaela Kühn,
Hasan Kulaksiz,
Knut Adermann,
Gerhard Bargsten,
D. Grube,
WolfGeorg Forssmann
Publication year - 1994
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.91.8.2935
Subject(s) - enterochromaffin cell , guanylate cyclase 2c , enteroendocrine cell , secretion , enterochromaffin like cell , biology , small intestine , gastric chief cell , gucy2d , immunocytochemistry , gastrointestinal tract , medicine , endocrinology , microbiology and biotechnology , biochemistry , cyclase , receptor , gastric acid , gastric mucosa , stomach , endocrine system , hormone , serotonin
Guanylin, a bioactive peptide, has recently been isolated from the intestine; this peptide activates intestinal guanylate cyclase (i.e., guanylate cyclase C) and thus is potentially involved in the regulation of water/electrolyte transport in the gastrointestinal mucosa. As yet, the cells involved in synthesis, storage, or secretion of guanylin have not been identified by immunocytochemistry. We raised antisera against guanylin and investigated the entire gastrointestinal tract of guinea pigs by light and electron microscopical immunocytochemistry. Extracts of various intestinal segments and plasma analyzed on a Western blot revealed a peptide band corresponding to the molecular mass of guanylin. Localization studies in the entire digestive tract showed that guanylin is exclusively confined to enterochromaffin (EC) cells. Remarkably, most EC cells contacted the gut lumen by cell processes that were highly immunoreactive for guanylin. In addition to the well known secretion in an endocrine fashion, EC cells by circumstantial evidence may release guanylin into the gut lumen to activate guanylate cyclase C that is immediately located on the brush border of adjacent enterocytes. The unique localization of guanylin in EC cells may indicate that these cells are involved in the regulation of fluid secretion in the gastrointestinal mucous membrane.