Relationship between amino acid dose and gastric secretory response.

Abstract

SUMMARY Gastric secretory dose-response studies, using an 8.5 % mixed L-amino acid solution as the agonist, were carried out in three dogs with Heidenhain pouches and gastric fistulae. Secretory responses of the Heidenhain pouches were measured during two hour infusions of amino acids given at rates of 0, 0.05, 0.1, 0-2, 0.4, 0.8, and 1.6 g/kg/h and plasma amino nitrogen was measured before and during the infusion. 4 September 1979 were performed aseptically with the dogs fully anaesthetised, and a recovery period of three to four weeks was allowed before secretory studies were undertaken. The studies were carried out after an 18 hour fast, during which water was allowed, and were repeated no more often than thrice weekly. With the dogs in modified Pavlov stands, an intravenous solution of 0.9% NaCI was begun. Secretion from the pouches was collected each 30 minutes and the H+ion content was determined; secretion from the main stomach was allowed to drain externally and was discarded. After a basal collection period of 60 minutes the test solution was administered by a peristaltic pump at a constant infusion rate for two hours. The test solution consisted of an 8.5% solution of mixed L-amino acids (Freamine II, McGaw Laboratories) given at a dose of 0.05, 0.1. 0.2, 0.4, 0.8, or 1.6 g/kg/h or of a solution of 0.9% sodium chloride (control) given at 30 ml/h. Only one dose was given on each test day and the order in which the various doses was given was randomised. Three tests at each dose, as well as three control infusions, were made in each dog. Blood was taken during the basal period and at 30 and 90 minutes after start of the test infusion. After centrifugation, the plasma was frozen and stored at -20C for subsequent amino nitrogen determinations by the method of Goodwin.7When the dose which gave the maximum response had been determined, a second series of experiments was carried out to ensure that hyperosmolarity of 91 on 10 May 2018 by guest. Protected by copyright.

Communications

“…The increase in plasma a-amino acid nitrogen concentration was sufficient to produce a gastric secretary response as documented by Gough et al (1980). The quantity of meat ingested (10 g/kg) was similar to the dog's daily meat intake and may therefore be described as typical.…”

“…Gough, Rai, Mariano & Landor (1980) suggested that increases in plasma a-amino acid nitrogen concentrations are capable ofeliciting a gastric secretary response. They assumed that values of 7-0-25-0 mg/tO0 ml plasma a-amino acid nitrogen concentration were obtained following a meal in the dog.…”