Physiological roles of preproghrelin-derived peptides in GH secretion and feeding

► Acyl, desacyl ghrelin and obestatin are gastrointestinal hormones obtained by post-translational processing of a common precursor, preproghrelin. ► Acyl ghrelin is a powerful stimulator of GH secretion and food intake while desacyl ghrelin and obestatin may modulate these actions. ► The function of obestatin remains controversial because several studies failed to reproduce its anorexigenic effect and its ability to bind and activate GPR-39. ► All preproghrelin-derived peptides are secreted in a pulsatile manner. While variations in acyl ghrelin have been correlated to feeding episodes, variations of these peptides in relation with GH secretion still needs to be fully characterized. ► More sensitive and selective assays to detect the different preproghrelin-derived peptides are being developed and may be the key to a better understanding of their roles in different physiological and pathological conditions.