Ghrelin: A gut hormonal basis of motility regulation and functional dyspepsia

Abstract

Functional dyspepsia (FD) is a functional gastrointestinal disorder (FGID). Several pathophysiological mechanisms have been indicated as possible etiological factors, such as delayed gastric emptying, impaired proximal gastric accommodation and visceral hypersensitivity. Ghrelin is an important gut hormone. It is a motilin-related peptide that was discovered in the stomach, and it acts as an endogenous ligand of growth hormone secretagogue receptor. Ghrelin plays an important role in the stimulation of food intake and gut motility. Acyl ghrelin stimulates the percentage motor index (%MI) in the antrum and induces fasted motor activity in the duodenum. Des-acyl ghrelin decreases food intake and decrease gastric emptying. Although some studies have demonstrated that plasma acyl ghrelin levels tend to be lower in FD patients than in controls, the association between plasma ghrelin levels and FD remains controversial. Previous reports have demonstrated that hunger sensation was elevated through the administration of ghrelin to patients with FD. However, there have been few clinical reports relating to the administration of ghrelin. Altered gut-brain interactions may underlie the symptoms of FD. Ghrelin may be associated with FD through its effect on the regulation of gut motility. Further studies are needed to examine the effects of ghrelin in FD.

The Preproghrelin 3056 TT Genotype is Associated with the Feeling of Hunger and Low Acylated Ghrelin Levels in Japanese Patients with <i>Helicobacter pylori</i>-negative Functional Dyspepsia

“…Ando et al reported that the preproghrelin gene 3056T->C SNP is associated with changes in the basal ghrelin concentrations (39). It is controversial whether any of the ghrelin gene SNPs alter the levels of ghrelin and/or obestatin (40,41). In this study, we also confirmed that the preproghrelin 3056TT genotype is significantly linked to low levels of acylated ghrelin in H. pylori-negative FD patients compared to healthy volunteers.…”

Diet and Irritable Bowel Syndrome, with a Focus on Appetite-Regulating Gut Hormones

“…Ghrelin has several functions, including regulating the release of somatotropin/growth hormone (GH) from the pituitary gland, where it acts synergistically with the GH-releasing hormone [136][137][138][139]. Moreover, ghrelin accelerates gastric and intestinal motility [140][141][142][143][144][145][146][147][148][149][150][151][152][153]. Ghrelin also increases appetite and feeding and plays a major role in energy metabolism [115,135].…”

MECHANISMS IN ENDOCRINOLOGY: Ghrelin: the differences between acyl- and des-acyl ghrelin

“…Finally, the ghrelin system is also linked to gonadal function (46,47), gut motility (39,48,49,50), and cancer (51,52,53,54), and it is highly likely that this relatively new hormone family will be linked to other medical conditions in the near future.…”