Metabolism of oxygenated derivatives of arachidonic acid by Caco-2 cells

Monolayers of Caco-2 cells, a human enterocyte cell line, were incubated separately with ³H₈-labeled preparations of three different lipid mediators of inflammation: 5-hydroxyeicosatetraenoic acid, 12-hydroxyeicosatetraenoic acid, and leukotriene B₄. Both [³H₈]5-hydroxyeicosatetraenoic and [³H₈]12-hydroxyeicosatetraenoic acids were taken up and metabolized by Caco-2 cells, but [³H]leukotriene B₄ remained unmetabolized in the incubation medium. [³H]5-hydroxyeicosatetraenoic acid was esterified into cellular phospholipids (15%) and triglycerides (4%) but did not undergo β- oxidation. When [³H]12-hydroxyeicosatetraenoic acid was incubated with Caco- 2 cells, 14% underwent two cycles of β-oxidation to form [³H]8- hydroxyhexadecatrienoic acid, and 3% underwent three cycles of β-oxidation to form [³H]6-hydroxytetradecadienoic acid, both of which were released into the media. [³H]12-Hydroxyeicosatetraenoic acid was also esterified into cellular phospholipids (13%), but none was esterified into cellular triglycerides.