Effect of ranitidine on gastric acid secretion in young male horses.
Gastric cannulas were placed surgically in 5 young male horses. After a 2-week recovery period, horses were studied once a week. Horses were fasted for 24 hours, and gastric fluid output was collected for 5 continuous hours. Volumes were recorded every 15 minutes, and pH and hydrogen ion concentration were determined in an aliquot from each period. In 10 basal experiments, using 5 horses, volume, pH, and hydrogen ion concentration were continuously variable. Mean acid output was 45.1 +/- 2.02 microEq/15 min/kg (mean +/- SEM). In 6 experiments, using 3 horses, 0.5 mg of ranitidine/kg of body weight, given as an IV bolus after a 1-hour basal collection, significantly (P less than 0.02) inhibited hourly total acid output for 4 hours, but did not significantly change pH. The cannulation technique was done without complications, and horses tolerated the cannula for several months. Seemingly, the horse has a continuously variable gastric acid secretion, and histamine type-2 receptors have a role in this process.
Campbell-Thompson
M L
ML
Department of Medical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610.
Merritt
A M
AM
D000818:Animals; D002404:Catheterization / Q000379:methods / Q000662:veterinary; D005744:Gastric Acid / Q000378:metabolism*; D006736:Horses / Q000502:physiology*; D008297:Male; D011899:Ranitidine / Q000494:pharmacology*; D013270:Stomach / Q000187:drug effects* / Q000502:physiology
D011899:Ranitidine