Lipoxin formation in fish leucocytes.

Adherent leucocytes, consisting of mainly macrophages, isolated from the haemopoietic head kidney of five species of fish were challenged with calcium ionophore and the resulting lipoxygenase products were separated and identified by reverse-phase high performance liquid chromatography. Of the fish examined, only adherent leucocytes from the Atlantic salmon and mirror carp generated lipoxins. Atlantic salmon leucocytes synthesized mainly lipoxin (LX) A4/LXA5 and 11-trans-LXA4/11-trans-LXA5, while mirror carp produced both LXA4 and LXB4 and their isomers but no 5-series lipoxins. This variation in lipoxin generation suggests that there are differences in the mode(s) of biosynthesis of these compounds between the two species of fish.