The Distribution of 15‐Hydroxy Prosta‐glandin Dehydrogenase and Prostaglandin‐Δ^13‐Reductase in Tissues of the Swine

Abstract

Abstract Prostaglandin dehydrogenase (15‐hydroxy prostanoate oxidoreductase, EC 1.1.1 (PGDH) and prostaglandin‐Δ 13‐ reductase (prostanoate Δ 13‐ oxidoreductase) were assayed in homogenates of 15 different tissues of the swine. Both enzymes were located mainly in the particle free fraction. The highest activities for PGDH were found in the lung, spleen and kidney, which ranged from 50–82 mU/g of tissue or from 482 to 808 m/g of protein. Lower activities of PGDH were observed in the stomach, testicle, liver and small intestine. The renal cortex contained about three times more PGDH than the medulla. The reductase was most abundant in spleen, kidney, liver, adrenal and small intestine, which ranged between 27–38 mU/g of tissue or 232–390 mU/g of protein. The highest specific activity was however found in adipose tissue which contained 3383 mU/g of protein. The wide distribution of these enzymes as well as other evidence support the concept that they catalyze the initial reactions in the metbolism of the prostaglandins.