Further evidence that substance P partly mediates the action of cholecystokinin octapeptide (CCK-8) on the guinea pig ileum but not gall bladder: studies with a substance P antagonist.
The substance P antagonist, [D-Pro4-D- Trp7 ,9,10]substance P4-11, caused a pig parallel shift to the right of the cholecystokinin (CCK-8) dose-response curve in guinea pig ileum longitudinal muscle without changing the maximal contraction. The shift of the CCK-8 dose response was markedly reduced after desensitization of the tissues to substance P (SP). The SP antagonist had no effect upon CCK-8 responses of the guinea pig gall bladder, [125I]CCK pancreatic binding or contractions of the guinea pig ileum produced by acetylcholine or electrical stimulation. The data provide additional evidence for the involvement of SP in the action of CCK-8 on the guinea pig ileum but not the gall bladder.
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005704:Gallbladder / Q000187:drug effects*; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000187:drug effects*; D009928:Organ Specificity; D012844:Sincalide / Q000494:pharmacology*; D013373:Substance P / Q000502:physiology*
D013373:Substance P; D012844:Sincalide