Sympathetic control of substance P releasing enteric neurones in the guinea pig ileum.
The contractile response of the isolated guinea-pig ileum to cholecystokinin octapeptide (CCK-8) that remained in the presence of atropine was greatly inhibited by the substance P antagonist D-Pro2,D-Trp7,9-substance P. This indicates that the atropine-resistant contraction to CCK-8 is mediated by the release of substance P from enteric neurones. Activation of alpha-adrenergic receptors by noradrenaline, clonidine or mesenteric sympathetic nerve stimulation inhibited the atropine-resistant contraction to CCK-8 but did not affect the contractile effect of substance P. It is concluded that alpha-adrenergic receptors exert an inhibitory influence on the release of substance P from enteric neurones.
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D004558:Electric Stimulation; D006168:Guinea Pigs; D007082:Ileum / Q000378:metabolism*; D009489:Neurosecretion / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D012844:Sincalide / Q000494:pharmacology / Q000502:physiology; D013373:Substance P / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology
D000316:Adrenergic alpha-Agonists; D011942:Receptors, Adrenergic, alpha; D013373:Substance P; C032132:substance P, prolyl(2)-tryptophan(7,9)-; D011433:Propranolol; D012844:Sincalide; D003000:Clonidine; D009638:Norepinephrine; D010646:Phentolamine