The effect of subdiaphragmatic vagotomy on the gastric mucus barrier in rats

1. Little information exists on the quantitation of mucus barrier and its vagal control; hence, the effect of vagotomy on the two components of the mucus barrier was studied in the glandular regions of rat stomach. 2. Bilateral subdiaphragmatic vagotomy was carried out by cutting both vagus nerves at the level of the lower end of the oesophagus. After 14 days, the glycoproteins in mucosal epithelial cells were identified by periodic acid Schiff's (PAS) staining technique and were assessed by calculating the ratio of the mucosal height to that of the thickness of PAS-positive materials in it. The adherent mucus was estimated by the Alcian blue binding technique and the results were compared with control animals subjected to mock vagotomy. 3. The bilateral subdiaphragmatic vagotomy caused a significant reduction in mucosal epithelial PAS-stainable materials content in oxyntic and pyloric gland areas. 4. The operation also caused a decrease in Alcian blue binding capacity of both the glandular regions. 5. The data suggest that the absence of vagal influence causes weakening of both the lines of mucus barrier. The findings support the hypothesis that the vagal system must be intact in the rat in order to maintain gastric mucus glycoproteins and thereby mucosal integrity.