Ava[l-Pro9,N-MeLeu10] Substance P(7-11) (GR 73632) and Sar9, Met(O2)11 Increase Distention-Induced Peristalsis through Activation of Neurokinin-1 Receptors on Smooth Muscle and Interstitial Cells of Cajal

Substance P is generally considered an excitatory neurotransmitter related to gut motor activity, although an inhibitory influence of neurokinin-1 (NK1) receptor activation on peristalsis has also been reported. With an optimized in vitro method to assess distention-induced peristalsis, our aim was to clarify the effect of NK1 receptor activation on peristaltic activity and to reveal the mechanisms by which NK1 activation alters peristalsis. …