Lipoxygenase activities of the epithelial cells of the human buccal cavity.

The lipoxygenase activities of cultured human buccal epithelial cells and cells taken ex vivo from the human buccal cavity were compared. Lipoxygenation by cultured cells exhibited exclusively omega-6 positional specificity. A membrane-damaging event such as freezing was required for activation. In contrast, after simple addition of arachidonic acid, the ex vivo buccal cells produced predominantly 12-hydroxyeicosatetraenoic acid. Chromatography on chiral columns yielded products which had an (S) configuration at the site of oxygen insertion. 5-hydroxyeicosatetraenoic acid was transformed by ex vivo buccal cells to 5(S),12(S)-dihydroxyeicosatetraenoic acid. These products could have a role in modulation of inflammatory states of the oral cavity.