Comparative study of antral gastrin activity in some mammals.

1. The amounts of crude gastrin extract and the gastrin activities of extracts from antral mucosa of several mammalian species have been determined.2. The yield of crude gastrin powder per gramme wet weight of antral mucosa was greater in goats and rabbits than in cat, dog, man or pig.3. Statistical differences do not appear to exist between the potencies of gastrin from the various species. The potencies of the powders were within the ranges 1.2-1.8 mug porcine gastrin II/mg with the exception of the extract from frozen dog antra (0.8 mug/mg).4. During prolonged freezing of animal antra and consequent thawing before extraction, significant losses in gastrin activity occurred in the dog.5. The amounts of gastrin activity per gramme wet weight of antral mucosa from herbivores (goat, rabbit and cattle) were greater than those from non-herbivores (cat, dog, man and pig).