In vivo chemotaxis induced by polyunsaturated fatty acids.

Intradermal injection of as little as 500 ng of arachidonic acid or the metabolites from arachidonic acid incubated with soybean lipoxygenase produced infiltration of the upper dermis by polymorphonuclear leukocytes 18 hours after injection. In experiments comparing the chemotactic properties of four fatty acids in varying concentrations, oxidative products of arachidonic acid by soybean lipoxygenase were the most powerful followed by free arachidonic acid and free linoleic acid while stearic acid did not produce significant infiltration. These findings suggest that the elevated levels of free arachidonic acid and an arachidonic acid metabolite (12L-hydroxy-5, 8, 10, 14-eicosatetraenoic acid), recently found in psoriatic epidermis, may at least in part be attracting polymorphonuclear leukocytes into psoriatic skin.