title: Impact of intracerebroventricular obestatin on plasma acyl ghrelin,             des-acyl ghrelin and nesfatin-1 levels, and on gastric emptying in rats.
abstract: Obestatin, which is a putative 23-amino-acid peptide, is derived from the C-terminal part of the mammalian preproghrelin gene. Nesfatin-1 mRNA is co-expressed with ghrelin in gastric endocrine X/A-like cells; therefore, nesfatin-1 may also interact with preproghrelin gene products in the stomach. In this study, we investigated the impact of obestatin on the plasma levels of acyl ghrelin, des-acyl ghrelin and nesfatin-1, and on the gastric emptying of a solid nutrient meal 2 h after an intracerebroventricular (ICV) injection in conscious, fasted rats. The rats were implanted with ICV catheters. Plasma levels of acyl ghrelin, des-acyl ghrelin and nesfatin-1, expected to be co-expressed with obestatin, were measured, whereas the human/rat corticotropin-releasing factor (h/rCRF) was applied as an inhibitor of gastric emptying. The ICV administration of obestatin (0.1, 0.3 and 1.0 nmol/rat) did not modify the plasma acyl ghrelin and des-acyl ghrelin levels, the acyl ghrelin/des-acyl ghrelin ratio and nesfatin-1 concentrations. The ICV acute administration of obestatin had no influence on the 2-h rate of gastric emptying of a solid nutrient meal, but the ICV h/rCRF injection delayed it. The weight of food ingested 1 h before ICV injection significantly, but negatively correlated with the gastric emptying of a solid nutrient meal. Our study indicates that the ICV injection of obestatin does not change the 2-h rate of gastric emptying of a solid nutrient meal and the relatively weak interrelationships between ghrelin gene products and nesfatin-1. However, the weight of the ingested food negatively affects the gastric emptying of a solid nutrient meal in conscious, fasted rats.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Taipei                     Veterans General Hospital, Taipei, Taiwan.
authors.forename: Chih-Yen
authors.initials: CY
authors.lastname: Chen
authors.forename: Wei-Jei
authors.initials: WJ
authors.lastname: Lee
authors.forename: Keong
authors.initials: K
authors.lastname: Chong
authors.forename: Shou-Dong
authors.initials: SD
authors.lastname: Lee
authors.forename: You-Di
authors.initials: YD
authors.lastname: Liao
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000097:blood*; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000097:blood*; D005502:Food; D005746:Gastric Emptying / Q000187:drug effects*; D054439:Ghrelin / Q000008:administration & dosage* / Q000097:blood*; D007276:Injections, Intraventricular; D008297:Male; D009419:Nerve Tissue Proteins / Q000097:blood*; D000080866:Nucleobindins; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D054439:Ghrelin; C000630650:NUCB2 protein, human; D009419:Nerve Tissue Proteins; C000630652:Nucb1 protein, rat; D000080866:Nucleobindins; C422650:ghrelin, des-n-octanoyl; D003346:Corticotropin-Releasing Hormone