AJP - Gastrointestinal and Liver Physiology, Vol 258, Issue 6 919-G925, Copyright © 1990 by American Physiological Society
Effects of antral vagotomy in dogs on gastrin and gastric secretion with various stimuli
B. I. Hirschowitz and J. Fong
Division of Gastroenterology, University of Alabama, Birmingham 35294.
In four gastric-fistula dogs, selective antral vagotomy markedly reduced
the vagal stimulation of gastrin release, thereby defining both the vagal
pathway for stimulation of gastrin and the anatomic source of such gastrin
release. Despite loss of gastrin response, vagal excitation by 100 mg/kg
2-deoxy-D-glucose (2-DG) produced the same acid and pepsin responses after
antral vagotomy as before, but there was an approximately 40% diminished
fundic response to pentagastrin, histamine, and synthetic human gastrin, as
well as to endogenous gastrin released by graded doses of bombesin.
Bethanechol did not reverse the defect, ruling out inadvertent fundic vagal
denervation, nor did raising serum gastrin by bombesin alter the response
to vagal stimulation by 2-DG. Fundic response to bethanechol was increased
by approximately 60%, and the output of gastrin increased at least fivefold
after antral vagotomy. Gastrin responses to food were diminished and those
to sham feeding were eliminated. Separation of the denervated antral pouch
had no additional effect on acid secretion. Vagal stimulation of gastric
secretion thus occurs almost exclusively through direct cholinergic effects
on the fundus with little or no contribution from antral gastrin. Vagal
denervation sensitizes the antrum to cholinergic stimulation.
