title: Conversions of prostaglandin endoperoxides by prostacyclin synthase from pig aorta.
abstract: Partially purified prostacyclin synthase from pig aorta converted the prostaglandin (PG) endoperoxide PGH2 to prostacyclin (PGI2), and PGH1 to 12-hydroxy-8,10-heptadecadienoic acid (HHD). Both reactions were inhibited by 15-hydroperoxy-5,8,11,13-eicosatetraenoic acid (15-HP) in a dose-dependent rashion. However, the reactions PGH2 leads to PGI2 and PGH1 leads to HHD appeared to differ: substrate availability was rate limiting in the latter reaction, while the enzyme became rapidly saturated witth PGH2 and a steady rate of prostacyclin formation was observed at higher substrate levels.
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha; D000818:Animals; D001011:Aorta / Q000201:enzymology*; D001095:Arachidonic Acids / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System; D011464:Epoprostenol / Q000096:biosynthesis* / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D006358:Hot Temperature; D019746:Intramolecular Oxidoreductases; D015289:Leukotrienes; D008054:Lipid Peroxides; D008861:Microsomes / Q000378:metabolism; D010545:Peroxides / Q000494:pharmacology; D011449:Prostaglandin Endoperoxides / Q000378:metabolism*; D011453:Prostaglandins / Q000096:biosynthesis*; D011458:Prostaglandins E / Q000378:metabolism; D011460:Prostaglandins F / Q000378:metabolism; D011463:Prostaglandins H / Q000378:metabolism; D013552:Swine
chemical_list: D001095:Arachidonic Acids; D005231:Fatty Acids, Unsaturated; D015289:Leukotrienes; D008054:Lipid Peroxides; D010545:Peroxides; D011449:Prostaglandin Endoperoxides; D011453:Prostaglandins; D011458:Prostaglandins E; D011460:Prostaglandins F; D011463:Prostaglandins H; C025560:12-hydroxy-8,10-heptadecadienoic acid; D015121:6-Ketoprostaglandin F1 alpha; C025086:15-hydroperoxy-5,8,11,13-eicosatetraenoic acid; C025559:12-hydroxy-4,8,10-heptadecatrienoic acid; D003577:Cytochrome P-450 Enzyme System; D011464:Epoprostenol; D019746:Intramolecular Oxidoreductases; C022461:prostacyclin synthetase