Metabolism of 12(R)-HETE in corneal tissue produces predominantly the compound resulting from the loss of four carbon atoms through β-oxidation from C-1. This metabolite is 8(R)-hydroxy hexadecatrienoic acid (8(R)-HHxTrE) or 2,3,4,5-tetranor 12(R)-HETE.

Biosynthesis of 12(R)-HETE in invertebrates is via lipoxygenation of arachidonic acid . In mammals, 12(R)-HETE can be produced by 12(R)-LOs and also by CYP450 oxidation. The activity of 12(R)-HETE in mammals is predominantly proinflammatory. 12(R)-HETE exhibits dose-dependent leukocyte chemotaxis at concentrations as low as 100 nM, and lowers intraocular pressure in rabbits.

12-OxoETE is synthesized by human platelets and Aplysia nervous tissue after incubation with arachidonic acid. Microsomal fractions of various tissues will reduce 12-oxoETE to 12(S)-HETE or a mixture of 12(S)- and 12(R)-HETE. 12-OxoETE induces a rapid, dose dependent increase of cytoplasmic free calcium via a leukotriene B4 receptor or a common activation sequence.

(±)12-HEPE is produced by non-enzymatic oxidation of EPA. It contains equal amounts of 12(S)-HEPE and 12(R)-HEPE. The biological activity of (±)12-HEPE is likely mediated by one of the individual isomers, most commonly the 12(S) isomer in mammalian systems. 12-HEPE inhibits platelet aggregation with the same potency as 12-HETE, exhibiting IC50 values of 24 and 25 µM, respectively. [1] These compounds are also equipotent as inhibitors of U46619-induced contraction of rat aorta (IC50s = 8.6-8.8 µM).[2]

12(R)-HEPE, a monohydroxy fatty acid derived from EPA in the eggs of the sea urchin S. purpuratus, has a biological activity that, while not extensively documented, may resemble that of 12(R)-HETE (Catalog No.34560).