Gastric Peptides and their Regulation of Hunger and Satiety

Abstract

Ingestion of food affects the secretion of hormones from specialized endocrine cells scattered within the intestinal mucosa. Upon release, these hormones mostly decrease food intake by signaling information to the brain. Although enteroendocrine cells in the small intestine were thought to represent the predominant gut-brain regulators of food intake, recent advances also established a major role for gastric hormones in these regulatory pathways. First and foremost, the gastric endocrine X/A-like cell was in the focus of many studies due to the production of ghrelin which is until now the only known orexigenic hormone that is peripherally produced and centrally acting. Although X/A-cells were initially thought to only release one hormone that stimulates food intake, this view has changed with the identification of additional peptide products also derived from this cell, namely desacyl ghrelin, obestatin and nesfatin-1. Desacyl ghrelin may play a counter-regulatory role to the food intake stimulatory effect of ghrelin. The same property was suggested for obestatin; however, this hypothesis could not be confirmed in numerous subsequent studies. Moreover, the description of the stomach as the major source of the novel anorexigenic hormone nesfatin-1 derived from the NUCB2 gene further corroborated the assumption that the gastric X/A-like cell is not only a stimulator but also an inhibitor of feeding thereby acting as so far unique dual regulator of food intake located in a logistically important place where the gastrointestinal tract has initial contact with food.

Nesfatin-1 as a New Potent Regulator in Reproductive System

“…Large amounts of the nesfatin-1 expression were detected in the digestive organs as well as the hypothalamus and brainstem. In particular, nesfatin-1 is markedly expressed in the pancreas, stomach and duodenum of rodent and canine ( Gonkowski et al, 2012 ; Iwasaki et al, 2012 ; Mohan & Unniappan, 2012 ; Osaki et al, 2012 ; Stengel et al, 2009c ; Stengel & Taché, 2012 ; Zhang et al, 2010 ).…”

Is excision of the gastric mucosa responsible for the superior outcomes of sleeve gastrectomy compared with gastric plication?

“…The gastric mucosa secretes orexigenic (ghrelin) and anorexigenic (leptin, obestatin, and nesfatin-1) hormones, making it a complex regulator of food intake and metabolism [4]. Additionally, increased insulin secretion and improved insulin sensitivity in diabetic obese patients immediately after sleeve gastrectomy, before any weight loss, supports the hypothesis that the benefits are a result of hormonal changes of gastric origin and are independent of gastric restriction and/or weight loss [3,5].…”

A RAPID Method for Blood Processing to Increase the Yield of Plasma Peptide Levels in Human Blood

“…In light of the worldwide increasing prevalence of obesity 1,2 , research in the field of food intake regulation is gaining importance. While so far only one peptide is known that is peripherally produced and centrally acting to stimulate food intake, namely ghrelin 3 , within the past decades, a broad range of peptides has been identified that reduce food intake, e.g. leptin, peptide YY (PYY) and also glucagon-like peptide-1 (GLP-1) and insulin 4 , Therefore, in studies investigating the regulatory mechanisms of hunger and satiety peptide levels are often assessed and at the same time, it is assumed that the peptide studied is stable and recovered at high yields during plasma formation.…”