Little or no ability of obestatin to interact with ghrelin or modify motility in the rat gastrointestinal tract
- 29 January 2007
- journal article
- Published by Wiley in British Journal of Pharmacology
- Vol. 150 (1), 58-64
- https://doi.org/10.1038/sj.bjp.0706969
Abstract
Obestatin, encoded by the ghrelin gene may inhibit gastrointestinal (GI) motility. This activity was re-investigated. Rat GI motility was studied in vitro (jejunum contractility and cholinergically-mediated contractions of forestomach evoked by electrical field stimulation; EFS) and in vivo (gastric emptying and intestinal myoelectrical activity). Ghrelin receptor function was studied using a GTPgammaS assay and transfected cells. Contractions of the jejunum or forestomach were unaffected by obestatin 100 nM or 0.01-1000 nM, respectively (P>0.05 each; n=4-18). Obestatin (0.1-1 nM) reduced the ability of ghrelin 1 microM to facilitate EFS-evoked contractions of the stomach (increases were 42.7+/-7.8% and 21.2+/-5.0 % in the absence and presence of obestatin 1 nM; P<0.05; n=12); higher concentrations (10-1000 nM) tended to reduce the response to ghrelin but changes were not statistically significant. Similar concentrations of obestatin did not significantly reduce a facilitation of contractions caused by the 5-HT(4) receptor agonist prucalopride, although an inhibitory trend occurred at the higher concentrations (increases were 69.3+/-14.0% and 42.6+/-8.7% in the absence and presence of 1000 nM obestatin; n=10). Obestatin (up to 10 microM) did not modulate recombinant ghrelin receptor function. Ghrelin increased gastric emptying and reduced MMC cycle time; obestatin (1000 and 30,000 pmol kg(-1) min(-1)) had no effects. Obestatin (2500 pmol kg(-1) min(-1), starting 10 min before ghrelin) did not prevent the ability of ghrelin (500 pmol kg(-1) min(-1)) to shorten MMC cycle time. Obestatin has little ability to modulate rat GI motility.Keywords
This publication has 22 references indexed in Scilit:
- Altered Gastrointestinal and Metabolic Function in the GPR39-Obestatin Receptor–Knockout MouseGastroenterology, 2006
- The prokinetic-like activity of ghrelin in rat isolated stomach is mediated via cholinergic and tachykininergic motor neuronesEuropean Journal of Pharmacology, 2006
- Obestatin alters sleep in ratsNeuroscience Letters, 2006
- Ghrelin gastrokinetic action in patients with neurogenic gastroparesisPeptides, 2006
- Differential BBB interactions of three ingestive peptides: Obestatin, ghrelin, and adiponectinPeptides, 2006
- Obestatin, a Peptide Encoded by the Ghrelin Gene, Opposes Ghrelin's Effects on Food IntakeScience, 2005
- Influence of ghrelin on gastric emptying and meal‐related symptoms in idiopathic gastroparesisAlimentary Pharmacology & Therapeutics, 2005
- Gastrokinetic effect of ghrelin analog RC-1139 in the rat: Effect on post-operative and on morphine induced ileusPeptides, 2005
- Ghrelin stimulates motility in the small intestine of rats through intrinsic cholinergic neuronsRegulatory Peptides, 2004
- Effect of ghrelin and growth hormone‐releasing peptide 6 on septic ileus in miceNeurogastroenterology & Motility, 2004