EFFECTS OF ANESTHETICS AND TRAUMA ON STIMULATED GASTRIC-ACID SECRETION IN CHRONIC FISTULA DOGS

1. The present study was undertaken to determine whether various anaes thetic agents affect canine gastric acid secretion independently of ot her experimental variables. 2. Acid secretory output was determined in dogs with chronic fistulae, by administering sedating doses of anaest hetics commonly used for studying gastric secretory mechanisms in labo ratory animals. 3. The anaesthetic agents inhibited gastric acid secre tion, As the inhibitory effect of the mixture of anaesthetics was pron ounced, an attempt was made to study the effect of each individual ana esthetic agent separately. 4. Acetopromazine was given to sedate dogs, Although it has a long duration of action, it only had a transient in hibitory action on gastric acid secretion of 15-30 min duration, Moreo ver the drug reduced pentagastrin-stimulated secretion, but had no eff ect on histamine-stimulated secretion. 5. Thiopentone sodium given wit h acetopromazine produced a mild inhibitory effect on histamine-stimul ated secretion for 45 min, but produced a more pronounced and sustaine d inhibitory effect on pentagastrin-stimulated secretion. 6. Trilene s ignificantly inhibited both histamine- and pentagastrin-stimulated sec retion, The effect on the latter was more pronounced and sustained. 7. Trauma had no significant effect on histamine-stimulated secretion, b ut showed a slight inhibitory effect on pentagastrin-stimulated secret ion. 8. Experiments to study gastric secretory mechanisms and antisecr etory drugs should take account of the potential inhibitory effects of anaesthetics, Where possible, studies in conscious dogs with gastric fistulae are preferable to experiments on anaesthetized animals.