Prostaglandin E2 20-hydroxylase in ampulla of vas deferens of sheep.

Microsomes were prepared from the ampullary mucosa of ram ductus deferens. The microsomal fraction was supplemented with 1 mM NADPH and was found to metabolize PGE2 to 20-hydroxy-PGE2. The product was identified by gas chromatography-mass spectrometry (GC-MS). The biosynthesis of 20-hydroxy-PGE2 was assessed by reversed-phase high performance liquid chromatography (HPLC) using 19-hydroxy-PGE1 as an internal standard and 0.2 mM PGE2 was found to be metabolized to 20-hydroxy-PGE2 at a rate of 7.1 pmol min-1 mg-1 of protein. Like a prostaglandin 20-hydroxylase of sheep vesicular glands, the 20-hydroxylase of the ampulla was only partly inhibited by metyrapone. 20-Hydroxy E prostaglandins, which occur in ram semen, are likely to be formed by the vesicular glands and the ampulla of vas deferens in the sheep.