Comparative physiological characteristics of the action of pentagastrin on gastric secretion in fish, frogs, turtles and chickens]

The same preparation of pentagastrin, which is highly effective in dogs (threshold dose 0.3 mug/kg), has been tested on fishes, frogs, tortoises and hens. In fishes (rays), the threshold dose was equal to 50 mug/kg; the drug only increased juice secretion, but did not decrease pH of the juice. In frogs, the effective dose was equal to 25, in tortoises -- to 50 mug/kg, the drug increasing the secretion of both the juice and HCl. The effect of the drug exhibits seasonal variations, being absent in winter period. In hens, the threshold dose is equal to 5 mug/kg; the drug increases both the volume of the juice and HCl production. In frogs and hens, similar to that in dogs (tortoises were not studied in this respect), pentagastrin also increases the production of proteases of gastric juice. It is suggested that in the animals studied pentagastrin is a specific stimulator of gastric secretion.