Modulation of prostaglandin E2 synthesis in rabbit synoviocytes.
Prostaglandin E2 (PGE2) production by rabbit synoviocytes was markedly stimulated by hydroxyapatite only after a 60-minute delay. Release of 3H-arachidonic acid (C20:4) and 3H-PGE2 from cells with phospholipids that were prelabeled with 3H-C20:4 did not occur in parallel. At 240 minutes, phospholipase activity in sonicated cell suspensions had increased only 38%, while cyclooxygenase activity had doubled (109%). This doubling, as well as the production of synoviocyte PGE2, was prevented by inhibiting the synthesis of protein. Cyclooxygenase is an inducible enzyme, and as such, it is a rate-controlling step in PGE2 production.
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D015232:Dinoprostone; D017886:Durapatite; D005260:Female; D006882:Hydroxyapatites / Q000494:pharmacology; D010741:Phospholipases A / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011458:Prostaglandins E / Q000096:biosynthesis*; D011817:Rabbits; D013583:Synovial Membrane / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism
D001095:Arachidonic Acids; D006882:Hydroxyapatites; D011458:Prostaglandins E; D016718:Arachidonic Acid; D017886:Durapatite; D003513:Cycloheximide; D011451:Prostaglandin-Endoperoxide Synthases; D010741:Phospholipases A; D015232:Dinoprostone