Orexins and gastrointestinal functions.

摘要: Orexin A (OXA) and orexin B (OXB) are recently discovered neuropeptides that appear to play a role in various distinct functions such as arousal the sleep-wake cycle well on appetite regulation of feeding energy homeostasis. Orexins were first described expressed by specific population neurons lateral hypothalamic area, region classically implicated behaviour. project numerous brain regions, where receptors have been shown be widely distributed: both OXA OXB act through two subtypes (OX1R OX2R) belong G protein-coupled superfamily receptors. Growing evidence indicates orexins central nervous system also regulate gastrointestinal functions: animal studies indeed demonstrated centrally-injected or endogenously released stimulates gastric secretion influence motility. The subsequent identification their enteric (including myenteric submucosal plexuses) mucosa smooth muscles has suggested these may local action. In this view, emerging indicate exert region-specific contractile relaxant effects isolated gut preparations. aim proposed review is summarize centrally- peripherally-mediated actions discuss related physiological basis most recent findings.