Role of NO in pyloric, antral, and duodenal motility and its interaction with other inhibitory mediators

Publisher Website
Google Scholar
Abstract
The antroduodenal region represents a crucial mechanism for the regulation of gastric emptying and prevention of duodenogastric reflux. The pylorus is characterized by a cholinergic excitation from the duodenum to the pylorus and by a potent nonadrenergic noncholinergic (NANC) inhibitory innervation, which can be activated by antral field stimulation and by extrinsic vagal stimulation. The inhibitory effect of both vagal stimulation and antral field stimulation can be abolishedin vivo by inhibitors of thel-arginine-NO pathway (l-NAME). During complete blockade of nitric oxide (NO) synthesisin vivo, the contractile response to intraarterial acetylcholine is enhanced and the direct inhibitory effect of vasocative intestinal peptide (VIP) is still present. Basal or vagally stimulated VIP release was not influenced byl-NAME. NO is a NANC inhibitory transmitter in the pylorus that exerts a tonic inhibition in the pyloric regionin vivo.