The gastric mucus layers: Constituents and regulation of accumulation

Mia Phillipson, Malin E.V. Johansson, Johanna Henriksnäs, Joel Petersson, Sandra J. Gendler, Stellan Sandler, A. Erik G. Persson, Gunnar C. Hansson, Lena Holm

Research output: Contribution to journalArticle

74 Scopus citations

Abstract

The mucus layer continuously covering the gastric mucosa consists of a loosely adherent layer that can be easily removed by suction, leaving a firmly adherent mucus layer attached to the epithelium. These two layers exhibit different gastroprotective roles; therefore, individual regulation of thickness and mucin composition were studied. Mucus thickness was measured in vivo with micropipettes in anesthetized mice [isoflurane; C57BL/6, Muc1-/-, inducible nitric oxide synthase (iNOS)-/-, and neuronal NOS (nNOS)-/-] and rats (inactin) after surgical exposure of the gastric mucosa. The two mucus layers covering the gastric mucosa were differently regulated. Luminal administration of PGE 2 increased the thickness of both layers, whereas luminal NO stimulated only firmly adherent mucus accumulation. A new gastroprotective role for iNOS was indicated since iNOS-deficient mice had thinner firmly adherent mucus layers and a lower mucus accumulation rate, whereas nNOS did not appear to be involved in mucus secretion. Downregulation of gastric mucus accumulation was observed in Muc1-/- mice. Both the firmly and loosely adherent mucus layers consisted of Muc5ac mucins. In conclusion, this study showed that, even though both the two mucus layers covering the gastric mucosa consist of Muc5ac, they are differently regulated by luminal PGE2 and NO. A new gastroprotective role for iNOS was indicated since iNOS-/- mice had a thinner firmly adherent mucus layer. In addition, a regulatory role of Muc1 was demonstrated since downregulation of gastric mucus accumulation was observed in Muc1-/- mice.

Original languageEnglish (US)
Pages (from-to)G806-G812
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume295
Issue number4
DOIs
StatePublished - Oct 1 2008

Keywords

  • Muc1
  • Muc5ac
  • Nitric oxide
  • Prostaglandin
  • iNOS

ASJC Scopus subject areas

  • Physiology
  • Hepatology
  • Gastroenterology
  • Physiology (medical)

Fingerprint Dive into the research topics of 'The gastric mucus layers: Constituents and regulation of accumulation'. Together they form a unique fingerprint.

  • Cite this

    Phillipson, M., Johansson, M. E. V., Henriksnäs, J., Petersson, J., Gendler, S. J., Sandler, S., Persson, A. E. G., Hansson, G. C., & Holm, L. (2008). The gastric mucus layers: Constituents and regulation of accumulation. American Journal of Physiology - Gastrointestinal and Liver Physiology, 295(4), G806-G812. https://doi.org/10.1152/ajpgi.90252.2008