“…Moreover, the enteric nervous system releases neurotransmitters, including gastrin-releasing peptide (GRP) [ 8 ] and pituitary adenylate cyclase-activating polypeptide (PACAP), further increasing local concentrations of gastrin and histamine, respectively (Fig. 1 ) [ 9 , 10 ]. Fig.…”
Section: Regulation Of Acid Secretionmentioning
confidence: 99%
“…CCK2 cholecystokinin receptor 2; GRP gastrin-releasing peptide; GRPR GRP receptor; H 2 histamine receptor type 2; M3 muscarinic receptor type 3; PACAP pituitary adenylate cyclase-activating polypeptide; PAC1 PACAP receptor type 1; SST somatostatin; SST2 SST receptor type 2; (+) stimulating action; (−) inhibitory action. ( Adapted from Wank [ 10 ].) …”
Luminal amino acids and lack of luminal acidity as a result of acid neutralization by intragastric foodstuffs are powerful signals for acid secretion. Although the hormonal and neural pathways underlying this regulatory mechanism are well understood, the nature of the gastric luminal pH sensor has been enigmatic. In clinical studies, high pH, tryptic peptides, and luminal divalent metals (Ca2+ and Mg2+) increase gastrin release and acid production. The calcium-sensing receptor (CaSR), first described in the parathyroid gland but expressed on gastric G cells, is a logical candidate for the gastric acid sensor. Because CaSR ligands include amino acids and divalent metals, and because extracellular pH affects ligand binding in the pH range of the gastric content, its pH, metal, and nutrient-sensing functions are consistent with physiologic observations. The CaSR is thus an attractive candidate for the gastric luminal sensor that is part of the neuroendocrine negative regulatory loop for acid secretion.
“…Moreover, the enteric nervous system releases neurotransmitters, including gastrin-releasing peptide (GRP) [ 8 ] and pituitary adenylate cyclase-activating polypeptide (PACAP), further increasing local concentrations of gastrin and histamine, respectively (Fig. 1 ) [ 9 , 10 ]. Fig.…”
Section: Regulation Of Acid Secretionmentioning
confidence: 99%
“…CCK2 cholecystokinin receptor 2; GRP gastrin-releasing peptide; GRPR GRP receptor; H 2 histamine receptor type 2; M3 muscarinic receptor type 3; PACAP pituitary adenylate cyclase-activating polypeptide; PAC1 PACAP receptor type 1; SST somatostatin; SST2 SST receptor type 2; (+) stimulating action; (−) inhibitory action. ( Adapted from Wank [ 10 ].) …”
Luminal amino acids and lack of luminal acidity as a result of acid neutralization by intragastric foodstuffs are powerful signals for acid secretion. Although the hormonal and neural pathways underlying this regulatory mechanism are well understood, the nature of the gastric luminal pH sensor has been enigmatic. In clinical studies, high pH, tryptic peptides, and luminal divalent metals (Ca2+ and Mg2+) increase gastrin release and acid production. The calcium-sensing receptor (CaSR), first described in the parathyroid gland but expressed on gastric G cells, is a logical candidate for the gastric acid sensor. Because CaSR ligands include amino acids and divalent metals, and because extracellular pH affects ligand binding in the pH range of the gastric content, its pH, metal, and nutrient-sensing functions are consistent with physiologic observations. The CaSR is thus an attractive candidate for the gastric luminal sensor that is part of the neuroendocrine negative regulatory loop for acid secretion.
Pituitary adenylate cyclase activating polypeptide (PACAP) is a multifunctional neuropeptide with widespread occurrence throughout the body including the gastrointestinal system. In the small and large intestine, effects of PACAP on cell proliferation, secretion, motility, gut immunology and blood flow, as well as its importance in bowel inflammatory reactions and cancer development have been shown and reviewed earlier. However, no current review is available on the actions of PACAP in the stomach in spite of numerous data published on the gastric presence and actions of the peptide. Therefore, the aim of the present review is to summarize currently available data on the distribution and effects of PACAP in the stomach. We review data on the localization of PACAP and its receptors in the stomach wall of various mammalian and non-mammalian species, we then give an overview on PACAP’s effects on secretion of gastric acid and various hormones. Effects on cell proliferation, differentiation, blood flow and gastric motility are also reviewed. Finally, we outline PACAP’s involvement and changes in various human pathological conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
