Inhibitory action of peptide YY on gastric acid secretion

Abstract

The purpose of this study is to investigate the effect of peptide YY (PYY) on pentagastrin-, histamine-, and bethanechol-stimulated gastric acid secretion and the possible mechanisms by which PYY inhibits gastric acid secretion. Six mongrel dogs with chronic gastric and duodenal fistulas were given an intravenous infusion of pentagastrin (0.5 microgram . kg-1 . h-1), histamine (18 micrograms . kg-1 . h-1), or bethanechol (80 micrograms . kg-1 . h-1) either alone or simultaneously with intravenous PYY (100, 200, 400, pmol . kg-1 . h-1). PYY (100, 200, 400 pmol . kg-1 . h-1) inhibited pentagastrin-stimulated gastric acid secretion in a dose-dependent manner. PYY (400 pmol . kg-1 . h-1) did not depress bethanechol-stimulated gastric acid secretion. PYY (400 pmol . kg-1 . h-1) also failed to inhibit histamine-stimulated gastric acid secretion. Furthermore, PYY inhibit pentagastrin-stimulated gastric acid secretion in the face of atropine, vagotomy, or indomethacin treatment. These findings indicate that the inhibitory action of PYY on gastric acid secretion is in part independent of long and short cholinergic pathways. These findings also indicate that the inhibitory mechanism of PYY is independent of prostaglandin synthesis. Our findings are discussed in relation to previous reports regarding the effects of PYY on gastric acid secretion.

Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery

“…Intracerebroventricular injection of PACAP stimulates gastric acid secretion (Ozawa et al, 1997), sug-324 gesting that PACAP may act centrally to regulate gastric acid release. The central effect of PACAP may involve peptide tyrosine tyrosine (PYY) as an indirect mediator (Guo et al, 1987), because intravenous injection of PACAP has been shown to increase plasma PYY concentrations . In the antrum of mammals, PACAP regulates locally the secretion of a number of peptides, including atrial natriuretic peptide (Gower et al, 2003), gastrin, and somatostatin (Tornøe et al, 2001).…”

Central and peripheral regulation of gastric acid secretion by peptide YY

“…The viewpoint of Pappas et al [65] was further confirmed by later studies in dogs [30] and rats [35]. In fasted rats, administration of PYY (3.2 nmol/kg/h, iv) had no effect on bethanechol-induced acid output, however, it inhibited baclofen-induced acid output by 61.8%, which was more potent compared with the inhibition on pentagastrinand histamine-induced acid output [35,36].…”

“…PYY and PYY are the two molecular forms of PYY abundant in the blood [25]. The PYY derivatives [Leu 31 , Pro 34 ] PYY (or Pro 34 PYY) and PYY (or PYY show selective affinity to Y1 and Y2 receptors respectively [6]. Circulating PYY displays a profound inhibitory action on gut motility, gastric emptying and acid secretion as well as pancreatic exocrine secretion [32,62,64,65].…”

PYY-Tag Transgenic Mice Displaying Abnormal (H+-K+)ATPase Activity and Gastric Mucosal Barrier Impairment

“…Peptide YY (PYY) and enteroglucagon are synthesized by L-type endocrine cells in the distal ileum and colon and have been shown to inhibit several gut functions including acid secretion (Adrian et al, 1985;Guo et al, 1987a;Pappas et al, 1986;Sheikh, 1991;Walsh, 1994). Considering the location of L cells in the distal gut, PYY and enteroglucagon may participate in the modulation of transit times, gastric and pancreatic secretion, and nutrient absorption (Goodlad et al, 1991).…”