Effect of jejunal resection on the gastric acid secretory response to pentagastrin, histamine and feeding in dogs

Effect of massive small bowel resection on gastric acid secretion in the rat

The phenomenon of a transitory gastric acid hypersecretory state after extensive bowel resection is well established. Its time of onset, however, is unknown. The purpose of this study was to determine the immediate effect of massive small bowel resection (MSBR) on gastric acid secretion (GAS). An anesthetized innervated rat model was prepared with gastric and jugular cannulae. Three groups of animals were studied: group I (n = 12), basal unstimulated state; group II (n = 12), pentagastrin (Pg) 16 micrograms/kg h-1 stimulated; and group III (n = 16), 5% liver extract meal (LEM) stimulated. Each group consisted of experimental animals that underwent 95% MSBR from proximal jejunum to terminal ileum and control animals that remained intact. Acid output was determined by extragastric titration with 0.1 M NaOH. Blood was taken for basal and postprandial serum gastrin levels. Basal acid output (mueq/10 min) significantly increased immediately after MSBR in all groups (p less than .01). Ninety minutes following MSBR, acid outputs were significantly elevated in basal and Pg-stimulated but not LEM-stimulated rats. Serum gastrin increased from 30 +/- 1 to 56 +/- 6 pg/mL (p less than .01) in group I rats and from 81 +/- 28 to 129 +/- 13 pg/mL in group III rats (p = NS). We conclude that GAS increases immediately after MSBR in group I and II rats. This increase in GAS may be mediated by gastrin release.

Gastric and pancreatic hyposecretion following massive small-bowel resection

It is well established that massive small-bowel resection (MSBR) invariably causes hypersecretion of acid in animals with denervated gastric pouches. The effect of MSBR on the secretory responses of both the totally innervated stomach and pancreas have been less well studied. Eighteen adult mongrel dogs were prepared with chronic gastric and pancreatic fistulae. In eight, massive small-bowel resection was performed in addition. Bowel resection did not alter the responses to graded doses of pentagastrin. However, in response to the intragastric titration of a liver extract meal, it had the following effects: (1) profound gastric acid hyposecretion; (2) reduction in pancreatic bicarbonate and protein secretion; and (3) increase in basal and meal-stimulated serum glucagon levels. Hypergastrinemia did not occur after resection. The hyposecretory responses may represent either increased inhibition or decreased secretory stimulation.