pgs-2

Prostaglandin F2α ethanolamide (PGF2α-EA) is produced by COX-2 metabolism of the endogenous cannabinoid, arachidonoyl ethanolamide (AEA), found in brain, liver, and other mammalian tissues. AEA can be metabolized directly by the sequential action of COX-2 and specific PG synthases to produce ethanolamide congeners of the classical PGs. PGF2α-EA has also been reported to be biosynthesized by this mechanism when AEA was infused into the lung and liver of living mice. PGF2α-EA is a potent dilator (EC50 = 58 nM) of the cat iris sphincter, which is a model system for testing potential intraocular hypotensive agents.

Prostaglandin H2 (PGH2), initially isolated from the incubation of arachidonic acid with ovine seminal vesicle microsomes, acts as a potent vasoconstrictor. It serves as the precursor for all 2-series prostaglandins (PGs) and thromboxanes (TXs). Moreover, as a TP receptor agonist, PGH2 irreversibly aggregates human platelets at concentrations of 50-100 ng ml.

19(R)-Hydroxylated prostaglandins (PGs) are present at µg ml concentrations in the semen of some mammalian species, notably primates, with the majority being from the PGE series and featuring a 15(S),19(R) hydroxyl stereochemistry. These compounds are also observed in marsupials' seminal plasma, where F-type 1 and 2-series compounds are predominant. The 15(R)-hydroxy epimer represents the inverse or unnatural isomer at C-15 for these 19-hydroxylated PGs. Although the biological function of 19(R)-hydroxylated PGs remains unclear, 19(R)-hydroxylation in the F-series leads to a notable reduction in receptor-mediated biological activity in certain assays.