title: Prostaglandin H synthase: protein synthesis-independent regulation in bovine aortic endothelial cells.
abstract: The objective of the present study was to examine whether prostaglandin H synthase (PGHS) can be regulated by pathways independent of de novo synthesis of PGHS. Incubation of bovine aortic endothelial cells (BAEC) for as short as 5 min with NaF (40 mM) resulted in a 60% increase in PGHS activity. PGHS activity induced by NaF was unaffected by either 10 microM cycloheximide or 1 microM actinomycin D. Aspirin (25 microM) completely inhibited resting PGHS activity, and NaF did not induce further stimulation. NS-398 (500 nM), a specific PGHS-2 inhibitor, was ineffective. Basic fibroblast growth factor (bFGF) induced a significant increase in PGHS activity within 30 min and was insensitive to cycloheximide. The levels of PGHS-1 and PGHS-2 proteins, as measured by Western blots, were not affected by NaF or bFGF. The tyrosine kinase inhibitor genistein attenuated PGHS activity that was induced by NaF and bFGF, whereas the tyrosine phosphatase inhibitor, sodium orthovanadate, augmented these responses. The G protein activators 5'-guanylyl imidodiphosphate and guanosine 5'-O-(3-thiotriphosphate) inhibited both resting and NaF-induced PGHS activities. These results suggest-that, in BAEC, PGHS-1 activity can be regulated by tyrosine kinase and/or G proteins, independently of de novo protein synthesis.
authors.affiliation: Department of Clinical Pharmacology, Corob Center for Health Sciences, Ben-Gurion University, Beer-Sheva, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Rosenstock
authors.forename: A
authors.initials: A
authors.lastname: Danon
authors.forename: G
authors.initials: G
authors.lastname: Rimon
mesh_terms: D017607:Aluminum Compounds / Q000494:pharmacology; D000818:Animals; D001011:Aorta; D001241:Aspirin / Q000494:pharmacology; D002417:Cattle; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000201:enzymology*; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005459:Fluorides / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism; D019833:Genistein / Q000494:pharmacology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis*; D007700:Kinetics; D009578:Nitrobenzenes / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D012969:Sodium Fluoride / Q000494:pharmacology*; D013449:Sulfonamides / Q000494:pharmacology; D013997:Time Factors; D014638:Vanadates / Q000494:pharmacology
chemical_list: D017607:Aluminum Compounds; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D009578:Nitrobenzenes; D011500:Protein Synthesis Inhibitors; D013449:Sulfonamides; D016222:Fibroblast Growth Factor 2; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D003609:Dactinomycin; D006165:Guanylyl Imidodiphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D014638:Vanadates; D012969:Sodium Fluoride; D003513:Cycloheximide; D019833:Genistein; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D011505:Protein-Tyrosine Kinases; D019204:GTP-Binding Proteins; D005459:Fluorides; D001241:Aspirin; C032311:aluminum fluoride