Abstract
The effects of CCT on the gut of guinea pig, rabbit and rat have been studied. CCT stimulated spontaneous motility of the isolated segment of small intestine, but it was less active with large intestine. Species difference was also observed. The strip of longitudinal muscle prepared from the rabbit ileum was more sensitive to CCT than that of the whole strip, and it was responsive even after storing in the ice box for 48 hours. CCT sensitized the longitudinal muscle to acetylcholine. The muscle strip from the reserpinized rabbit still responded to CCT. Conversely the circular muscle strip did not react to CCT. Stimulant actions of CCT on the isolated ileum of guinea pig were not affected by preincubation with atropine, hexamethonium, diphenhydramine or harmine. CCT, administered i.v., also stimulated the movement of ileum in the rabbit. These findings suggested a myogenic nature of the CCT activity.
