The effect of copper ion on arachidonic acid metabolism in the porcine corneal epithelium

The effect of copper ion on arachidonic acid metabolism in the corneal epithelium was studied. Our results showed that when ³H-arachidonic acid (1 μCi/μg) was incubated with homogenate of corneal epithelium at 37°C for 45 min., three metabolites were formed. Metabolite A, the major metabolite, was identified as 12-HETE by HPLC and GC. An analysis with chiral phase HPLC revealed that metabolite A was a (R)-enantiomer. The production of 12(R)- HETE was stimulated by low concentrations of CuCl₂ (<0.1 mM) and inhibited by higher concentrations of CuCl₂. Study on the biological activity of 12(R)-HETE showed that it could stimulate migration of endothelial cells in a concentration as low as 10 ng/ml. These results suggest that one of the effects of copper ion on the corneal neovascularization may be to regulate the level of 12(R)-HETE.