New actors in the gut :emerging players in motility and in inflammatory bowel diseae

Gastrointestinal motility is an integrated process generated and modulated by local and circulating hormones and neurotransmitters which act and interact directly and indirectly on muscle cells. A plethora of regulators have been identified, but this field is continuously in expansion. Among the new actors in gut accumulating evidence strongly supports a role of renin-angiotensin system (RAS) in the digestive tract cooperating with other major mediators for maintaining gastrointestinal homeostasis. Transcripts encoding RAS components were detected in gastrointestinal tract and the involvement of RAS in gut motility modulation is increasingly emerging. The available literature demonstrated that Angiotensin II (Ang II), the main peptide of RAS, induces smooth muscle contraction in human and animal gastrointestinal preparations, mostly modulating the main enteric excitatory systems via AT1 receptors. We will focus our attention on recent studies underlined the connection between Ang II and gastrointestinal inflammation. Since inflammation in the gut is usually accompanied by alteration of gastrointestinal motility, new drugs that interfere with RAS could be used in the future for the treatment of both inflammatory bowel disease (IBD)-related gastrointestinal motor dysfunction and inflammation itself.