Vagal nerve stimulation of the XXXX oesophagus.

@entity4033 @entity2951 @entity840 @entity1022 @entity12064 @entity3897 @entity42187 @entity2607 @entity2899
Vagal nerve stimulation of the isolated @entity840 oesophagus resulted in a triphasic contractile response which was abolished by @entity1022 . The mechanisms for each of the three responses were investigated. The first response was abolished by the neuromuscular blocking drug, @entity2899 , and was unaffected by @entity3897 . The second response to vagal nerve stimulation was abolished by the ganglion blocking drug, @entity4033 , and by @entity2899 at a higher concentration than that required to block the first response. The second response was also abolished by @entity3897 and was enhanced by @entity2607 . It was concluded that this response was due to preganglionic stimulation of smooth muscle. @entity42187 GVIA selectively inhibited the third response. This response was resistant to the neuromuscular and ganglion blocking drugs yet was abolished by @entity3897 and was enhanced by @entity2607 . This implicates the involvement of cholinergic neurones activated independently of nicotinic ganglionic receptors. The third response was also selectively abolished by @entity2951 and enhanced by @entity12064 . Contractile responses resulting from exogenous substance P were abolished by @entity3897 and @entity1022 and enhanced by @entity2607 . These findings suggest that the third response may be mediated by the action of a substance P-like neuropeptide released from sensory nerve endings which subsequently activate cholinergic neurones.
