The anatomy of the gastrin cell.
Changes in the numbers of G cells and the formation and release of gastrin granules have been studies by means of radioimmunoassay and quantitative electron microscopy. The appearance of G-cell granules was affected by the pH and duration of fixation, and after prolonged fixation immature newly formed granules could be identified. In rats fasting up to 3 days first the release and then in turn the maturation and synthesis of granules were depressed. Ultimately the renewal of G cells was inhibited and their numbers declined. During an acute stimulus only a small proportion of total antral gastrin was released and the appearance of G cells was unaltered. In patients treated with cimetidine for 12 months there was no G-cell hyperplasia despite raised stimulated gastrin levels.
D000818:Animals; D002452:Cell Count; D002927:Cimetidine / Q000627:therapeutic use; D004381:Duodenal Ulcer / Q000188:drug therapy / Q000473:pathology; D005755:Gastrins / Q000378:metabolism*; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D011706:Pyloric Antrum / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D011863:Radioimmunoassay; D051381:Rats
D005755:Gastrins; D002927:Cimetidine