Use of a cannula insert in erratic emptying Heidenhain pouch dogs: effect of single and cumulative doses of omeprazole.

A novel cannula insert was used to correct erratic emptying in Heidenhain pouch dogs. The insert restored the recovery of histamine or pentagastrin stimulated gastric acid secretion to that obtained from normal emptying pouch dogs, probably by displacing obstructing tissue within the pouch. Use of the insert did not cause any discomfort to the animals, nor did it alter basal secretion. There was no significant difference between the antisecretory activity of single doses of omeprazole in erratic emptying animals fitted with the insert (ED50 = 0.21 mumol/kg) and in dogs with a normal pouch (ED(50) = 0.13 mumol/kg). Use of the insert achieved an earlier steady secretory response which allowed cumulative dosing to be performed in each animal. There was no significant difference between the effect of cumulative (ED50 = 0.24 mumol/kg) and single doses of omeprazole in erratic emptying dogs. Although there was a significant difference between cumulative dosing in erratic emptiers and single dosing in normal animals it should still be possible to use erratic emptiers with the insert for screening purposes.