12(S)-HYDROXY-5,8,10,14-EICOSATETRAENOIC ACID IS A MORE POTENT NEUTROPHIL CHEMOATTRACTANT THAN THE 12 (R) EPIMER IN THE RAT CORNEA

12(R)-hydroxy-5,8.10.14-eicosatetraenoic acid [12(R)-HETE] is reported to be more potent than its epimer 12(S)-HETE as a chemoatractant for human neutrophils in vitro and following topical applicaton to the skin. To assess the in vivo neturophil chemoattractant potencies of 12(S)-HETE and 12(R)-HETE in the rat, we injected 1 μg, 5 μg, or 10 μg of these eicosanoids into teh corneal stroma. Rats were killed 12-15 hours after injection, and the number of neutrophils in the stroma was counted in a histological section of the cornea including the injection site. The number of neutrophyls was significantly increased in corneas injected with 5 μg (+103% of control) or 10 μg (+456% of control) of 12(S)-HETE and in those injected with 10 μg of 12(R)-HETE (+11% of control). The neutrophilic infiltrate in corneas injected with 1 μg or 5 μg of 12(S)-HETE was not significantly different form that in corneas injected with 1 μg of leukotriene BE4. The data for the 10 μg injections indicate that 12(S)-HETE is a more potent neutrophil chemoattractant than 12(R)-HETE in the rat cornea. Our results suggest that species or 12-HETE epimers as chemoatractans for neutrophils and that 12(S)-HETE may be an important inflammatory mediator in the rat cornea. © 1990.