title: Action of the SP2-11 and SP3-11 fragments of substance P on rat peritoneal mast cells.
abstract: The ability of the SP fragments SP2-11 and SP3-11 to release histamine from rat peritoneal mast cells has been compared with that of the whole peptide. SP1-11 was found to be about 3.4 times more active than SP2-11 and about 10.4 times more active than SP3-11. The substance P antagonist [D-Pro4, D-Trp7,9,10] SP4-11 was equally effective at antagonizing the histamine releasing action of SP1-11, SP2-11 and SP3-11. Benzalkonium chloride was found to be a competitive antagonist of SP and SP3-11: the dissociation constants for the benzalkonium chloride-receptor interaction being about the same when either SP1-11 or SP3-11 was used as the agonist.
mesh_terms: D000818:Animals; D006636:Histamine Release / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D008407:Mast Cells / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013268:Stimulation, Chemical; D013329:Structure-Activity Relationship; D013373:Substance P / Q000037:antagonists & inhibitors* / Q000494:pharmacology*
chemical_list: D010446:Peptide Fragments; D013373:Substance P