AJP - Regulatory, Integrative and Comparative Physiology, Vol 259, Issue 6 1259-R1266, Copyright © 1990 by American Physiological Society
Basal and pentagastrin-stimulated gastric secretion in young horses
M. L. Campbell-Thompson and A. M. Merritt
Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32610.
Equine gastric secretion was studied using a gastric cannula model after
fasting (basal) and pentagastrin infusion. Gastric secretory rate, pH,
osmolality, and electrolyte concentrations and outputs were determined over
a 5-h period. Dose-response tests estimated that the maximally effective
intravenous dose of pentagastrin was between 3 and 6 micrograms.kg-1.h-1.
Basal secretory rate was 278 +/- 29 (SE) ml/15 min, and the pH was 2.00 +/-
0.31. Pentagastrin infusion at 6 micrograms.kg-1.h-1 increased secretory
rate to 533 +/- 60 ml/15 min and decreased pH to 1.41 +/- 0.11. Basal
gastric acid concentration and output were 38 +/- 5 meq/l and 211 +/- 36 mu
eg.kg-1.h-1, respectively. Pentagastrin increased acid concentration to 60
+/- 5 meq/l and acid output to 474 +/- 61 mu eq.kg-1.h-1. Gastric fluid
osmolality remained hypotonic during both basal and pentagastrin
conditions. Sodium concentration remained high in comparison with hydrogen
ion concentration, and sodium output increased during pentagastrin
infusion. Equine gastric secretion did not attain maximal acid
concentrations nor the marked drop in pH, which has been reported for other
monogastric species. These data suggest that in the horse a large
nonparietal component exists that modifies parietal secretions and is
increased by pentagastrin stimulation.
