PT  - JOURNAL ARTICLE
AU  - Christina Vafeas
AU  - Paul A. Mieyal
AU  - Ferdinando Urbano
AU  - John R. Falck
AU  - Kamlesh Chauhan
AU  - Michael Berman
AU  - Michal Laniado Schwartzman
TI  - Hypoxia Stimulates the Synthesis of Cytochrome P450-Derived Inflammatory Eicosanoids in Rabbit Corneal Epithelium
DP  - 1998 Dec 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 903--910
VI  - 287
IP  - 3
4099  - http://jpet.aspetjournals.org/content/287/3/903.short
4100  - http://jpet.aspetjournals.org/content/287/3/903.full
SO  - J Pharmacol Exp Ther1998 Dec 01; 287
AB  - The corneal epithelium metabolizes arachidonic acid by a cytochrome P450-(CYP) mediated pathway to 12(R)hydroxy-5,8,10,14-eicosatrienoic acid [12(R)-HETE] and 12(R)hydroxy-5,8,14-eicosatrienoic acid [12(R)-HETrE]. Both metabolites possess potent inflammatory properties with 12(R)-HETrE being a powerful angiogenic factor and assume the role of inflammatory mediators in hypoxia- and chemical-induced injury in the cornea, in vivo. We developed an in vitro model of corneal organ culture to characterize the biochemical and molecular events involved in the increased synthesis of these metabolites. These cultured corneas exhibit epithelial cytochrome P450 CYP-dependent 12(R)-HETE and 12(R)-HETrE synthesis as indicated by chiral analysis and by the ability of CYP enzyme inhibitors to repress their synthesis. Hypoxia greatly and selectively stimulated the synthesis of 12(R)-HETE (7-fold over control normoxic conditions) and 12(R)-HETrE. The bacterial endotoxin, lipopolysaccharide, also increased the synthesis of these eicosanoids, substantiating the notion that this activity may function as an inflammatory pathway. These metabolites were detected in the culture medium by gas chromatography/mass spectroscopy (GC/MS) analysis and their levels significantly increased in hypoxia-treated corneas, further indicating their endogenous formation in response to injury. This in vitro model provides an excellent preparation for studying factors regulating the synthesis of these inflammatory eicosanoids and for isolating, identifying and characterizing the CYP protein responsible for their synthesis. The American Society for Pharmacology and Experimental Therapeutics