The relation between thromboxane and prostaglandin synthesis in human decidua tissue: a comparison of eicosanoid synthesis in minced tissue with that in a cell-free preparation.
Radiotracer studies and radioimmunoassay measurements demonstrate that minced tissues of human decidua produce chiefly thromboxane B2 (TxB2) (70% of total eicosanoids) and small amounts of prostaglandin F2 alpha (PGF2 alpha) (13%) PGD2 (8%), 6-keto-PGF1 alpha (5%) and PGE2 (4%). Inhibition of thromboxane synthesis with a specific inhibitor (OKY-1581: sodium (E)-3-[4(-3-pyridylmethyl)-phenyl]-2-methyl propenoate) increased prostaglandin formation in general, with the main product being PGF2 alpha (38%), a nonenzymic derivative of PGH2. Crude particulate fractions prepared from the same tissue synthesized two major products from [3H]arachidonate, TxB2 and 6-keto-PGF1 alpha (54 and 30%, respectively) and some PGF2 alpha and PGE2 (8-8%). However, in the presence of reduced glutathione (GSH), PGE2 became the main product (81%) (TxB2, 15%; PGF2 alpha, 2%; and 6-keto-PGF1 alpha, 2%). Half-maximal stimulation of PGE2 synthesis occurred at 46 microM GSH. The GSH concentration of tissue samples was found to be 110 +/- 30 microM. We conclude that human first trimester decidua cells possess the key enzymes of prostaglandin and thromboxane synthesis. Apparently, the production of these compounds is controlled by a specific mechanism in the tissue, which keeps PGE and prostacyclin synthesis in a reversibly suppressed state, whereas the formation of thromboxane is relatively stimulated.
Asbóth
G
G
First Institute of Biochemistry, Semmelweis University of Medicine, Budapest, Hungary.
Gimes
G
G
Hertelendy
F
F
Tóth
M
M
D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D002474:Cell-Free System; D003656:Decidua / Q000187:drug effects / Q000378:metabolism*; D015237:Dinoprost / Q000096:biosynthesis; D015232:Dinoprostone / Q000096:biosynthesis; D005260:Female; D005978:Glutathione / Q000494:pharmacology; D006801:Humans; D008689:Methacrylates / Q000494:pharmacology; D011247:Pregnancy; D015230:Prostaglandin D2 / Q000096:biosynthesis; D011453:Prostaglandins / Q000096:biosynthesis*; D013929:Thromboxane B2 / Q000096:biosynthesis*; D013930:Thromboxane-A Synthase / Q000037:antagonists & inhibitors
D001095:Arachidonic Acids; D008689:Methacrylates; D011453:Prostaglandins; D016718:Arachidonic Acid; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; C031517:2-methyl-3-(4-(3-pyridinylmethyl)phenyl)-2-propenoic acid; D015237:Dinoprost; D013930:Thromboxane-A Synthase; D005978:Glutathione; D015232:Dinoprostone; D015230:Prostaglandin D2