Parietal cell structure and acid secretion in the vagally innervated stomach and the vagally denervated fundic pouch in cats.

In seven cats provided with gastric fistula (GF) of the main stomach and a denervated Heidenhain pouch (HP) the structure of the innervated and denervated mucosa was examined by light and electron microscopy. In four of these cats dose-response curves for acid output to pentagastrin were determined before and after vagal denervation of the fundic pouch. Vagal denervation reduced the acid response to pentagastrin by decreasing both the secretory capacity and the sensitivity of the oxyntic glands. Accordingly, in the same cat the parietal cells of the HP were less sensitive to pentagastrin than the cells of the innervated main stomach. Light and electron microscopic investigations revealed that the fundic mucosa was thinner, and the size and proportion of the parietal cells was smaller in the HP than in the GF. It is likely that the morphological changes in the pouch were caused by the vagal denervation rather than by the loss of mucosal contact with food. The secretory and morphological changes produced by the vagotomy are not necessarily related.