Arachidonoyl
ethanolamine (
anandamide) and pros-taglandin
ethanolamines (prostamides) are biologically active derivatives of
arachidonic acid. Although available through different precursor
phospholipids, there is considerable overlap between the biosynthetic pathways of
arachidonic acid-derived
eicosanoids and
anandamide-derived prostamides. Prostamides exhibit physiological actions and are involved in
ocular hypotension, smooth muscle contraction, and inflammatory
pain. Although topical application of
bimatoprost, a structural analog of
prostaglandin F2α ethanolamide (PGF2α-EA), is currently a first-line treatment for
ocular hypertension, the endogenous production of prostamides and their biochemical precursors in corneal tissue has not yet been reported. In this study, we report the presence of
anandamide, palmitoyl-, stearoyl-, α-linolenoyl docosahexaenoyl-, linoleoyl-, and oleoyl-
ethanolamines in rabbit cornea, and following treatment with
anandamide, the formation of PGF2α-EA, PGE2-EA, PGD2-EA by corneal extracts (all analyzed by LC/ESI-MS/MS). A number of N-acyl
phosphatidylethanolamines, precursors of
anandamide and other fatty acyl
ethanolamines, were also identified in corneal
lipid extracts using ESI-MS/MS. These findings suggest that the prostamide and
fatty acid ethanolamine pathways are operational in the cornea and may provide valuable insight into corneal physiology and their potential influence on adjacent tissues and the aqueous humor.