Cyclooxygenase metabolism of EPA to produce PGE3 has been reported in biosynthetic preparations of ovine seminal vesicles and in the ocular tissues of primates. PGA3 is an expected non-enzymatic dehydration product of this PGE3. PGA3 exhibits good affinity for the canine EP2 and EP4 receptors with IC50 values of 120 nM and 20 nM, respectively, in a radioligand binding assay. PGA3 has weak affinity for human PPARγ, with a Ki value of 188 µM.