title: In vitro activities of some synthetic substance P analogs.
abstract: Substance P (SP) and several analogs and fragments have been synthesized and evaluated on non-stimulated and stimulated guinea-pig ileum. In the former test system the potency order was as follows: SP(4--11) greater than SP = [Tyr7]-SP = [Eth11]-SP = [Nle11]-SP greater than [Dala9]-SP greater than SP(7--1) = [Tyr7]-SP(7--11) greater than [Eth11]-SP(7--11) greater than [DAla9]-SP(7--11) greater than [Nle11]-SP(7--11) greater than SP(1--7). The spasmogenic activity of SP and analogs was preserved in the same potency order on stimulated guinea-pig ileum; none of these modifications resulted in an analog with narcotic-like activity. These data are discussed in terms of a hypothetical SP receptor in extravascular smooth muscle.
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D013329:Structure-Activity Relationship; D013373:Substance P / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D013373:Substance P