title: Tachykinins: effects on motility and metabolism of rat polymorphonuclear leucocytes.
abstract: Chemotactic and chemoluminescent activities of substance P, substance K, kassinin and the substance P fragments SP 4-11, SP 7-11, SP 1-4 have been investigated in order to identify the minimum active molecular structure responsible for rat polymorphonuclear activation. Substance P, SP 4-11 and SP 7-11 stimulated directed locomotion (chemotaxis) and were found to be active also in the chemoluminescence assay while SP 1-4 had no effect. Moreover, all peptides, except substance K and SP 1-4, inhibited the chemotactic response of polymorphonuclears to the peptide formyl-methionyl-leucyl-phenylalanine and, to a minor extent, also to leukotriene B4. A maximum of activity was observed with the C-terminal sequence SP 4-11. Substance K was found to be inactive. Kassinin exhibited a weak chemotactic effect and exerted a slight inhibition of attracting activity of peptide-formyl-methionyl-leucyl-phenylalanine. Considering that substance P and related peptides are active only at very high concentrations, it cannot be affirmed that these agents activate specific receptors. If receptors are involved, they would be of the SP-P type, since substance K is inactive.
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000187:drug effects; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D066298:In Vitro Techniques; D007705:Kinins / Q000494:pharmacology*; D007975:Leukotriene B4 / Q000494:pharmacology; D008163:Luminescent Measurements; D008297:Male; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009479:Neuropeptides / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology*; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000494:pharmacology; D015320:Tachykinins
chemical_list: D007705:Kinins; D009479:Neuropeptides; D015320:Tachykinins; D007975:Leukotriene B4; D013373:Substance P; D009240:N-Formylmethionine Leucyl-Phenylalanine