Interactions of gastrointestinal peptides: ghrelin and its anorexigenic antagonists

Abstract

Food intake behaviour and energy homeostasis are strongly regulated by a complex system of humoral factors and nerval structures constituting the brain-gut-axis. To date the only known peripherally produced and centrally acting peptide that stimulates food intake is ghrelin, which is mainly synthesized in the stomach. Recent data indicate that the orexigenic effect of ghrelin might be influenced by other gastrointestinal peptides such as cholecystokinin (CCK), bombesin, desacyl ghrelin, peptide YY (PYY), as well as glucagon-like peptide (GLP). Therefore, we will review on the interactions of ghrelin with several gastrointestinal factors known to be involved in appetite regulation in order to elucidate the interdependency of peripheral orexigenic and anorexigenic peptides in the control of appetite.

Figure 1

Peripheral and central peptides reducing (↓) or stimulating (↑) food intake (modified after Arora et al. [5]). AgRP: agouti-related peptide; CART: cocaine and amphetamine regulated transcript; CCK: cholecystokinin; CRF: corticotropin releasing factor; DAG: desacyl ghrelin; GLP: glucagon-like peptide; MSH: melanocyte stimulating hormone; NPY: neuropeptide Y; POMC: proopiomelanocortin; PP: pancreatic polypetide; PYY: peptide YY; TRH: thyreotropin releasing hormone.