Fasting gastric content of the squirrel monkey (Saimiri sciurea)

Abstract

Free acid was found in the fasting gastric contents of each of 13 squirrel monkeys studied. A comparison of gastric contents from unrestrained and restrained monkeys indicated that restraint significantly increased the free acid concentration. Over a 24-hr period, there was a decrease in volume, free acid and total acid concentration, and pepsin value of the gastric juice. Histamine (0.1 mg/kg hr, subcutaneously) produced a significant increase in free acid and total acid concentration, while the volume and pepsin values were not changed. Methacholine, at cumulative doses of 1.0 and 2.0 mg/kg, subcutaneously, produced a significant decrease in free and total acid concentration while the volume was not altered. Atropine, in cumulative doses of 8, 16, and 48 mg/kg, intraperitoneally, produced a significant fall in volume of gastric juice collected. However, free acid concentration was reduced only at the highest dose and total acid concentration was not changed by any of the doses tested.