Abstract
Gastric acid secretion has been measured in the codfish (Gadus morhua) equipped with a catheter draining the stomach, by titrating the water swallowed by the fish. Unstimulated acid secretion was found to be very low; in most fishes not exceeding 8 mumol H+/kg h. Intramuscular injection of histamine evokes a dose-dependent secretion of gastric acid, with a maximum acid output of 300 mumul/kg h occurring with 10 mg/kg histamine dihydrochloride. No acid response was obtained with pentagastrin.