Regulation of atrial natriuretic peptide gene expression in gastric antrum by fasting

Abstract

Atrial natriuretic peptide (ANP) gene expression was localized in the rat gastric antrum using immunohistochemistry and in situ hybridization to mucosal cells in the lower portion of the antropyloric glands. Colocalization of immunoreactive ANP, long-acting natriuretic peptide, i.e., proANP-(1-30), and serotonin in these cells identified them to be enterochromaffin cells. Fasting for 72 h in 8-mo-old (adult) rats produced a significant (P < 0.05) decrease in the levels of ANP prohormone mRNA, immunoreactive proANP-(1-30) and ANP to approximately 33% of that of fed rats. Fasting in 1-mo-old rats had no effect on these parameters. Transcripts for natriuretic peptide receptor subtypes NPR-A, NPR-B, and NPR-C were found in both mucosa and muscle tissues of the antrum. ANP, brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) stimulated the production of cGMP in antral mucosa in vitro with a potency of ANP > BNP >> CNP, suggesting that these receptors were functional. We conclude that fasting decreases ANP prohormone mRNA and its gene products, long-acting natriuretic peptide, and ANP in the antrum of adult rats.

Blockade of Multidrug Resistance-Associated Proteins Aggravates Acute Pancreatitis and Blunts Atrial Natriuretic Factor’s Beneficial Effect in Rats: Role of MRP4 (ABCC4)

“…María Silvia Ventimiglia, 1 Ana Clara Najenson, 1 Juan Carlos Perazzo, 1 Alejandro Carozzo, 3 Marcelo S Vatta, 2 Carlos A Davio, 3 and Liliana G Bianciotti We previously reported that atrial natriuretic factor (ANF) stimulates secretin-evoked cAMP efflux through multidrug resistanceassociated protein 4 (MRP4) in the exocrine pancreas. Here we sought to establish in vivo whether this mechanism was involved in acute pancreatitis onset in the rat.…”

“…Atrial natriuretic factor (ANF) is a key regulator of cardiovascular and renal function, but compelling evidence supports its physiological role in the digestive system where it modulates digestive motility and secretions in a paracrine and/or autocrine manner (1)(2)(3)(4). We previously reported that ANF through natriuretic peptide receptor type C (NPR-C) receptors coupled to phospholipase C/ protein kinase C (PLC/PKC) negatively modulates secretin intracellular signaling by stimulating secretin-evoked cAMP out of the pancreatic acinar cells through multidrug resistance-associated protein 4 (MRP4) (5,6).…”

C-type natriuretic-peptide-potentiated relaxation response of gastric smooth muscle in streptozotocin-induced diabetic rats

“…NPR-A preferentially binds ANP and BNP, but has a low affinity for CNP; NPR-B has a much higher affinity for CNP than either ANP or BNP [13] . NPs are also secreted from gastric mucosa [14][15][16] . Our previous study indicated that CNP relaxes gastric circular and longitudinal smooth muscles in human, rat and guinea-pig stomach, and that NPRs are distributed in rat gastric smooth muscle layer [17][18][19] .…”

Gastric atrial natriuretic peptide regulates endocrine secretion in antrum and fundus of human and rat stomach

“…In anesthetized rats, low doses of ANP augmented vagally induced acid secretion, whereas higher doses reduced vagally induced acid secretion as well as that induced by carbachol (26). With the use of ribonuclease protection analysis and RT-PCR, we have detected the expression of ANP mRNA in antral and fundic mucosa of rat stomach, with the antrum having threefold higher levels of ANP transcripts than the fundus (10). In the antrum, the ANP-expressing cells were identified as enterochromaffin cells by dual immunohistochemistry and colorimetric in situ hybridization (10).…”

“…somatostatin; gastrin; histamine; atrial natriuretic factor; natriuretic peptide receptor; hormone; peptide; guanylyl cyclase-A ATRIAL NATRIURETIC PEPTIDE (ANP), also known as atrial natriuretic factor, a 28-amino acid polypeptide first identified in cardiac atrial myocytes, is also present in a variety of extracardiac tissues including the stomach (9,10,14,29). ANP preferentially binds to two subtypes of natriuretic peptide receptors (NPR), NPR-A [also known as guanylyl cyclase-A (GC-A) or NPR1] and NPR-C (also known as NPR3) (14).…”