Synthesis of leukotriene B and other conjugated triene lipoxygenase products by blood cells of the rainbow trout, Salmo gairdneri

Stimulation of whole blood from rainbow trout with the calcium ionophore, A23187 (20 microM), produced leukotrienes B4 and B5 at concentrations in the range 22-30 ng.ml-1 and 8-24 ng.ml-1, respectively. Their identification and quantification was achieved using reverse-phase high-performance liquid chromatography, combined capillary column gas chromatography-electron capture chemical ionization mass spectrometry and ultraviolet spectroscopy. A number of other lipoxygenase products were also detected, but only partially analysed. The fatty acid composition of the leucocytes, which are presumed to be the site of leukotriene synthesis, was determined by thin-layer and gas-liquid chromatography to enable a comparison of the relative levels of the polyunsaturated fatty acids, which act as substrates for the synthesis of these lipoxygenase products. Arachidonic (20:4(n - 6)), eicosapentaenoic (20:5(n - 3)) and docosahexaenoic (22:6(n - 3)) acids represented approx. 6, 5 and 40%, respectively, of the total fatty acid content.