Objective Ghrelin is a 28aamino acid peptide derived from a prepropeptide of 117 residues, named pre-proghrelin. Very recently it was identified a new ghrelin-associated peptide encoded by a 23aamino acid peptide, with a flanking conserved glycine residue at the C terminus named obestatin. Obestatin showed a high affinity for GPR39 and needs an amidation to be biologically active. Regarding its physiological effects, obestatin is able to antagonize ghrelin effects on food intake, body weight and gastric emptying, but had no effect on growth hormone levels. Intraperitoneal and intracerebroventricular injection of obestatin suppressed food intake in a time- and dose-dependent manner. In contrast, treatment with the non-amidated obestatin was less effective. The fact that the same precursor leads to two different peptides with orexigenic and anorexigenic actions shows us that energy balance depends not only of the expression of different peptides but also the rate of transcription from the precursor to aSleana or aSfata gene is very important. As it is typical when a new discovery appears, numerous unanswered questions arise and further studies will be necessary to find those answers. For instance, even obestatin decreased the food intake and body weight in rodents, serum leptin levels were not affected after treatment with obestatin, suggesting minimal modulation of body-fat content. Moreover, fasting did not change serum obestatin levels and circulating levels of obestatin are much lower than ghrelin, thus the relevance of endogenous obestatin remains unclear. Finally, from a pharmacological point of view, the most interesting will be to check if obestatin changes the food intake or the body weight in humans. Fields of science natural sciencesbiological sciencesbiochemistrybiomolecules Keywords ghrelin obesity obestatin Programme(s) FP6-MOBILITY - Human resources and Mobility in the specific programme for research, technological development and demonstration "Structuring the European Research Area" under the Sixth Framework Programme 2002-2006 Topic(s) MOBILITY-2.2 - Marie Curie Outgoing International Fellowships (OIF) Call for proposal FP6-2005-MOBILITY-6 See other projects for this call Funding Scheme OIF - Marie Curie actions-Outgoing International Fellowships Coordinator UNIVERSIDADE DE SANTIAGO DE COMPOSTELA EU contribution No data Address Pazo de San Xerome - Praza do Obradoiro s/n SANTIAGO DE COMPOSTELA Spain See on map Links Website Opens in new window Total cost No data Participants (1) Sort alphabetically Sort by EU Contribution Expand all Collapse all UNIVERSITY OF CINCINNATI OBESITY RESEARCH CENTRE United States EU contribution No data Address 2170 E Galbraith Road CINCINNATI See on map Links Website Opens in new window Total cost No data
