The influence of graded distension and carbachol on the motor response to cholecystokinin in isolated guinea-pig antrum and fundus.

Graded distension increased the motor response to cholecystokinin and acetylcholine both in antral and fundal pouches. The increase became even more obvious when the pressure responses were converted into changes in wall tension. The responses to cholecystokinin were additive with low doses (10(-7)M) of carbachol, but diminished or abolished by prestimulation with higher doses. The results indicate that the increased response to cholecystokinin after distension is due to increased smooth muscle stretch.