Inhibition of food passage by omeprazole in the chicken

The effect of omeprazole, a proton pump inhibitor, on the forward passage of the crop contents of chicks receiving 20% medium chain or long chain triacylglycerol was studied. Medium chain triacylglycerol significantly delayed the crop emptying of chicks compared with long chain triacylglycerol. Omeprazole also significantly inhibited passage from the crop of the long chain triacylglycerol meal. Application of omeprazole induces achlorhydria and consequently hypergastrinemia but chicken gastrin lower than 100 nmol/kg did not delay crop emptying. The addition of hydrochloric acid (HCl) to the diet reversed the action of omeprazole on the crop emptying of chicks. We conclude, then, that omeprazole delayed the crop emptying in chicks as a consequence of inhibition of acid secretion, although the mediator is not gastrin.