PYY‐preferring receptor in the dorsal vagal complex and its involvement in PYY stimulation of gastric acid secretion in rats

Microinjection of peptide YY (PYY, 7–46 pmol) into the dorsal vagal complex (DVC) stimulated gastric acid secretion in urethane‐anaesthetized rats. Using a variety of neuropeptide Y (NPY) and PYY derivatives, we characterized the pharmacological profile of the receptor mediating the acid secretory response to PYY. [Pro 34 ]rat(r)/porcine(p)PYY and [Pro 34 ]human(h)PYY (23–117 pmol), microinjected unilaterally into the DVC resulted in a similar maximal increase in net acid secretion reaching 68±11 and 89±31 μmol 90 min −1 respectively. Rat/hNPY and pNPY (47 pmol) microinjected into the DVC induced a similar net gastric acid secretion (27±8 and 23±8 μmol 90 min −1 respectively) and a higher dose (116 pmol) tended to reduce the response. Pancreatic polypeptide (PP, 4–46 pmol), [Leu 31 ,Pro 34 ]r/hNPY (47 and 117 pmol) and the Y2 selective agonists, hPYY 3‐36 , pNPY 5‐36 and pNPY 13‐36 (25–168 pmol) microinjected into the DVC failed to influence basal gastric acid secretion. The rank order of potency of PYY[Pro 34 ]r/pPYY=[Pro 34 ]hPYY>r/hNPY=pNPY to stimulate gastric acid secretion upon injection into the DVC and the ineffectiveness of PP, [Leu 31 ,Pro 34 ]NPY and C‐terminal NPY/PYY fragments suggest that a PYY‐preferring receptor subtype may be involved in mediating the stimulating effect.British Journal of Pharmacology (1998) 123 , 1549–1554; doi: 10.1038/sj.bjp.0701767