Article Text

PDF

Gastrin and the ultrastructure of G cells in the fasting rat.
  1. N J Mortensen,
  2. J F Morris,
  3. C Owens

    Abstract

    The effect of fasting on serum and antral gastrin concentrations and G cell ultrastructure in the rat has been examined using a radioimmunoassay and quantitative electron microscopy. Serum gastrin levels in fasting animals were markedly reduced and there was also a significant decrease in antral gastrin concentrations after 48 hours and 72 hours of fasting. This was associated with a significant fall in the granule content and cytloplasmic volume of individual G cells, at its greatest by 48 hours. A relative absence of electron dense granules in the Golgi zones of cells from animals fasted for 72 hours suggested a paucity of newly formed granules, but fasting produced no detectable change in the electron density of the granule population taken as a whole. The results indicate that, during fasting, release and then synthesis of gastrin is inhibited, so that granule stores and cell size diminish. The correlation between the granule content of G cells and the antral content of gastrin suggests that hormone release occurs by exocytosis, rather than by any change in the content of individual granules.

    Statistics from Altmetric.com

    Request permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.