Effects of gastric fundic stimulation on glucose absorption and water and electrolyte fluxes from rabbit small bowel.

A single-pass perfusion model was developed to measure net fluxes of glucose, water, sodium, and potassium across upper jejunal and duodenal mucosa in vivo in the anaesthetised rabbit. Irrigation of the gastric fundic mucosa with Michaelis' buffer (pH 8) reduced jejunal mean glucose absorption by 21.3% (P less than 0.04) and duodenal glucose absorption by 27.2%. Irrigation of gastric fundic mucosa with 0.1 M glycine at pH 2 increased mean jejunal glucose absorption by 25%. Jejunal net secretion of water and sodium were reduced by gastric fundic alkali. Potassium net fluxes in jejunum and duodenum were not significantly affected. These results support the hypothesis that the gastric fundic mucosa is sensitive to chemical stimulation, responding by a humoral mechanism that modified the rate of glucose absorption from the small bowel mucosa.