title: Novel structural determinants of the human neutrophil chemotactic activity of leukotriene B.
abstract: A specific 5(S),12(R)-dihydroxy-eicosa-6,8,10(trans/trans/cis), 14(cis)-tetraenoic acid, designated leukotriene B, is generated by the lipoxygenation and subsequent enzymatic hydration of arachidonic acid in a variety of leukocytes. Leukotriene B elicits a maximal human neutrophil chemotactic response in vitro which is similar in magnitude to those evoked by the chemotactic fragment of the fifth component of complement, C5a, synthetic formyl-methionyl peptides, and 5-hydroxy-eicosatetraenoic acid (5-HETE). The neutrophil chemotactic potency of purified leukotriene B, assessed by the 50% effective concentration of 6 x 10(-9) M, is equivalent to that of C5a, but is up to 100-fold greater than that of 5-HETE and of other natural di-HETE isomers. 5(S),12(R)-di-hydroxy-eicosa-6,8,10(all-trans),14(cis)-tetraenoic acid, which differs from leukotriene B only in having a trans-double bond in place of a cis-double bond in the triene portion of the molecule, and acetyl-leukotriene B are significantly less potent neutrophil chemotactic factors than leukotriene B, which indicates that both the conjugated double bonds and the free hydroxyl-group(s) are functionally critical determinants. The capacity of acetyl-leukotriene B to inhibit competitively and selectively the human neutrophil chemotactic response to equimolar concentrations of leukotriene B suggests the existence of a specific subset of receptors for this potent lipid mediator.
mesh_terms: D000107:Acetylation; D001095:Arachidonic Acids / Q000494:pharmacology; D055598:Chemical Phenomena; D002621:Chemistry; D002634:Chemotaxis, Leukocyte; D003182:Complement C5; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids; D007975:Leukotriene B4; D009239:N-Formylmethionine / Q000031:analogs & derivatives / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine; D009504:Neutrophils; D009842:Oligopeptides / Q000494:pharmacology
chemical_list: D001095:Arachidonic Acids; D003182:Complement C5; D006893:Hydroxyeicosatetraenoic Acids; D009842:Oligopeptides; D007975:Leukotriene B4; D009239:N-Formylmethionine; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid; D009240:N-Formylmethionine Leucyl-Phenylalanine