Formation of lipoxins by alveolar macrophages

Rat alveolar macrophages incubated with (15S), 15-hydroperoxy-5,8, 11-cis-13-trans-eicosatetraenoic acid (15-HPETE) in the presence of the calcium ionophore A23187 produced a series of polar compounds. Reverse-phase high performance liquid chromatography (RP-HPLC) was used to purify these compounds and their identities were characterized by physical criteria (UV spectroscopy, GC/MS) and by co-elution with synthetic compounds. Alveolar macrophage-derived materials proved to be lipoxin A4 [LXA4; (5S, 6R, 15S)-5,6,15-trihydroxy-7,9,13-trans-11-cis-eicosatetraenoic acid], lipoxin B4[LXB4; (5S, 14R, 15S)-5,14,15-trihydroxy-6,10,12-trans-8-cis- eicosatetraenoic acid], and a structural isomer. These results indicate that rat alveolar macrophages have the capacity to generate lipoxins and related compounds.