Pressure-responses to cholecystokinin in the fundus and antrum of isolated guinea-pig stomachs.

Cholecystokinin produced dose-dependent increases in motor activity in antral and fundal pouches of isolated guinea-pig stomachs. The response was immediate; the motor activity increased to a peak within 2 min, then decreased somewhat, but stabilized within 5 min at a value that was higher than before addition of cholecystokinin. In the antral pouches the response consisted of an increase in the amplitude of the rhythmic contractins; in the fundal pouch it was seen as an increase in basal pressure. The antral response was significantly greater in pouches distended to an initial basal pressure of 15-25 cm H2O than in undistended pouches. The fundal reponse was not enhanced by distension.