Ultrastructure of gastric fundus glands of refed mice

Abstract

The present investigation is an extension of a previous study on the ultrastructure of the fundus glands of the mouse and deals with the electron microscopic appearance of these glands 1, 3, and 6 hours after refeeding. In the post-prandial period the greatest ultrastructural changes are observed in the zymogen cells. The mean diameter of the zymogen granules is reduced by some 40% 1 hour after refeeding; later in the postprandial period their size increases slowly. The Golgi apparatus occupies a larger space than in the fasted animals. The α -cytomembranes lose their regular arrangement, and the cisternal spaces bounded by them appear to increase their volume. The morphology of the microvilli and the mitochondria remains unchanged. The alterations in the parietal cells consist mainly of an increase of the number of microvilli and a dilatation of the intracellular canaliculi. The mean diameter of the microvilli is reduced 1 hour after refeeding, but later their fasting size is regained. The number of vacuoles appears to be reduced in some cells, but their mean diameter does not change significantly. The appearance of the mitochondria is not influenced by refeeding. No major changes are observed in the ultrastructure of the mucoid cells after refeeding. The argyrophile cells exhibit no definite postprandial alterations.