Gastric emptying and intestinal transit in Bufo marinus and the actions of E prostaglandins.

Gastric emptying and intestinal transit have been studied in the anuran Bufo marinus using Tc99-labelled chicken liver as the test meal. Gastric emptying was measured as the proportion of the test meal remaining in the stomach after 3 or 6 h. Intestinal transit was calculated by the geometric centre method at the same time intervals. There was a high degree of variability in these parameters between individual animals, in both control and treated groups. Both SC29333 (Searle), a synthetic E prostaglandin, and prostaglandin E2 given orally delayed gastric emptying. These results complement the finding that prostaglandin E2 causes relaxation of anuran longitudinal muscle in vitro, and lend further support to the suggestion that prostaglandin E2 may be responsible for the gut stasis associated with gastric brooding in the gastric brooding frog Rheobatrachus silus.