Effect of pentagastrin on small bowel structure and function in the rat.

Since chronic pentagastrin stimulates pancreatic and proximal duodenal growth (15), we studied jejunal structure and function following subcutaneous pentagastrin (2 mg-100 g-1 day-1). After 15 days, macroscopic enlargement was confined to the proximal duodenum with a significant increase in wet weight (from 231 +/- SEM 6 to 308 +/- 13 mg) but there was no significant difference in wet and defatted dry intestinal weights, histological measurements of villous height and mucosal thickness or in glucose absorption per unit length of distal duodenum and proximal jejunum. Since chronic pentagastrin causes parietal cell hyperplasia and hypersecretion of gastric acid, the results suggest that the adaptive changes seen in the jejunum after ileectomy are neither mediated by gastrin nor by factors present in gastric secretions.