Phosphate buffer stimulates somatostatin release into the antral lumen of anaesthetized cats

The effect of variations of intra-antral pH on the intraluminal release of somatostatin was studied. Acute pouches were created in anaesthetized cats, and the pouches were perfused with solutions differing in pH. Somatostatin levels were then measured in the perfusates. In this model phosphate buffer was a potent stimulator of intra-antral somatostatin release, whereas perfusion with 0.1 M HCl failed to release somatostatin by itself. Since phosphate buffer also releases gastrin, the releasing effect ought to be exerted beyond the mechanism that can be blocked by somatostatin. (Thus the stimulatory effect of phosphate buffer might be exerted on the membranes of the endocrine cells.)