Interaction of substance P with dispersed pancreatic acinar cells from the guinea pig. Relationships between structure, binding and biological activity.
Binding of 125I-[Tyr8]-SP to isolated pancreatic acinar cells was inhibited in a concentration-dependent way by SP, [Tyr8]-SP and longer C-terminal fragments of SP. SP6-11 was the shortest sequence to bind significantly to SP-receptors as well as to stimulate amylase release from dispersed pancreatic acini. SP7-11 and shorter fragments did not inhibit binding of 125I-[Tyr8]-SP and did not stimulate secretion of amylase significantly. SP augmented the stimulatory effect of cholecystokinin on amylase release. Two SP-antagonists, [D-Pro2, D-Trp7,9]-SP and [D-Pro2,4, D-Lys3, D-Gln5,6, D-Trp7,9]-SP inhibited binding of 125I-[Tyr8]-SP in a concentration dependent manner and tended at a high concentration to reduce release of amylase evoked by submaximal concentrations of SP.
D000681:Amylases / Q000378:metabolism; D000818:Animals; D006168:Guinea Pigs; D008297:Male; D010179:Pancreas / Q000166:cytology / Q000378:metabolism*; D010446:Peptide Fragments / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018040:Receptors, Neurokinin-1; D012844:Sincalide / Q000494:pharmacology; D013373:Substance P / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology
D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D018040:Receptors, Neurokinin-1; C041238:substance P, iodo-Tyr(8)-; D013373:Substance P; C032132:substance P, prolyl(2)-tryptophan(7,9)-; D000681:Amylases; D012844:Sincalide