title: Characterisation of the binding of leukotriene B4 to macrophages of the rainbow trout Oncorhynchus mykiss.
abstract: The binding of leukotriene B4 (LTB4) to macrophages from the head kidney of the rainbow trout Oncorhynchus mykiss was measured. Binding of [3H]LTB4 achieved a steady state after approximately 30 min of incubation and was 30% reversible in the presence of a minimum of 1000-fold excess of LTB4. Scatchard analysis of the kinetics of LTB4 binding over a range of [3H]LTB4 concentrations indicated the existence of only a single class of receptor with a dissociation constant, KD, of 0.14 nmol l-1 and a maximum receptor density, Bmax, of approximately 17,800 sites per macrophage. The LTB4 receptor antagonist LY223982 was ineffective in inhibiting the binding of [3H]LTB4 to trout macrophages, although another receptor antagonist, LTB4-dimethylamide, displaced a maximum of 25% of the total binding. LTB5 was equally effective as LTB4 at displacing [3H]LTB4, while other eicosanoids tested were without significant effect. It is suggested that the putative receptors for LTB4 on trout macrophages are similar to the high-affinity receptors for this compound reported to occur on mammalian granulocytes, although any structural similarities of the binding sites await further investigation.
authors.affiliation: School of Biological Sciences, University of Wales Swansea, UK.
authors.forename: L A
authors.initials: LA
authors.lastname: Bowden
authors.forename: S
authors.initials: S
authors.lastname: Fiore
authors.forename: C J
authors.initials: CJ
authors.lastname: Restall
authors.forename: C N
authors.initials: CN
authors.lastname: Serhan
authors.forename: A F
authors.initials: AF
authors.lastname: Rowley
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D007668:Kidney / Q000276:immunology; D007975:Leukotriene B4 / Q000378:metabolism*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D017686:Oncorhynchus mykiss / Q000276:immunology*
chemical_list: D007975:Leukotriene B4