A progression in the development of gastritis is not observed following selective proximal vagotomy. Morphometrically, a moderate compensatory foveolar hyperplasia can be noticed in addition to a reduction of parietal cells. Paralleles can be found concerning the ultrastructural alterations of parietal cells following vagotomy or after anticholinergic treatment. They consist in an increase of lamellar osmiophilic bodies, reduction of tubulovesicles, a narrow canalicular lumen and sparse mitochondria. A few years after vagotomy, the parietal cells appear rather unstimulated. After vagotomy, numerous antral G-cells can be demonstrated, with ultrastructural features of increased secretory activity in correlation to raised plasma gastrin levels. This moderate G-cells hyperplasia may, however, already exist preoperatively with the duodenal ulcer. 5 years after vagotomy, there is no pronounced alteration concerning the number of granular or agranular vesicles inside the terminal axons. Experimentally, a degeneration of sympathetic nerves has been described a few days after vagotomy.