Orexins and gastrointestinal functions.
Curr Protein Pept Sci
; 11(2): 148-55, 2010 Mar.
Article
em En
| MEDLINE
| ID: mdl-20353399
ABSTRACT
Orexin A (OXA) and orexin B (OXB) are recently discovered neuropeptides that appear to play a role in various distinct functions such as arousal and the sleep-wake cycle as well as on appetite and regulation of feeding and energy homeostasis. Orexins were first described as neuropeptides expressed by a specific population of neurons in the lateral hypothalamic area, a region classically implicated in feeding behaviour. Orexin neurons project to numerous brain regions, where orexin receptors have been shown to be widely distributed both OXA and OXB act through two subtypes of receptors (OX1R and OX2R) that belong to the G protein-coupled superfamily of receptors. Growing evidence indicates that orexins act in the central nervous system also to regulate gastrointestinal functions animal studies have indeed demonstrated that centrally-injected orexins or endogenously released orexins in the brain stimulates gastric secretion and influence gastrointestinal motility. The subsequent identification of orexins and their receptors in the enteric nervous system (including the myenteric and the submucosal plexuses) as well as in mucosa and smooth muscles has suggested that these neuropeptides may also play a local action. In this view, emerging studies indicate that orexins also exert region-specific contractile or relaxant effects on isolated gut preparations. The aim of the proposed review is to summarize both centrally- and peripherally-mediated actions of orexins on gastrointestinal functions and to discuss the related physiological role on the basis of the most recent findings.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neuropeptídeos
/
Neurotransmissores
/
Trato Gastrointestinal
/
Peptídeos e Proteínas de Sinalização Intracelular
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Curr Protein Pept Sci
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Itália