Metabolism of [14C] arachidonic acid in the isolated rabbit spleen

Infusion of [14C] arachidonic acid (AA) into the isolated, Tyrode perfused rabbit spleen resulted in the release of a substance into the venous effluent with the musculotropic activity and chromatographic properties of prostaglandin (PG)E2. Smaller amounts of radioactive materials with the chromatographic properties of PGF2 alpha, 6-keto-PGF1 alpha, and PGD2 were also released. The radiolabeled material released in largest amounts from the spleen was identified as PGE2 on the basis of: 1) Co-chromatography with PGE2 in three solvent systems, 2) Conversion of the radioactive material and of authentic [3H] PGE2 to similar products by treatment with sodium borohydride and with potassium hydroxide, and 3) Stability of the musculotropic activity in Tyrode solution at 37 degrees C. Release of the major and minor radioactive products was inhibited by pretreatment of the spleen with either indomethacin or 5,8,11,14-eicosatetraynoic acid.