title: Modulation of superoxide generation in in vivo lipopolysaccharide-primed Kupffer cells by staurosporine, okadaic acid, manoalide, arachidonic acid, genistein and sodium orthovanadate.
abstract: Continuous infusion of a nonlethal dose of Escherichia coli lipopolysaccharide (LPS) into rats induced extravasation of mononuclear phagocytes into the liver and the priming of Kupffer cells for in vitro phorbol myristate acetate (PMA)-stimulated superoxide anion (O2-) release. The purpose of this investigation was to determine the role of protein kinase C (PKC), protein serine-threonine phosphatase(s) 1 and 2a, protein tyrosine kinase(s) and phosphatase(s), phospholipase A2 (PLA2), arachidonic acid (AA) and its cyclooxygenase (CO) and 5-lipoxygenase (5-LO) metabolites in the modulation of PMA-stimulated O2-generation in in vivo LPS-primed rat Kupffer cells. The following inhibitors blocked PMA-stimulated O2- generation in the absence (-AA) or presence of AA (+AA) (50 microM): 1) staurosporine, a putative PKC inhibitor (150 nM, 95% inhibition without AA, 88% inhibition with AA); 2) okadaic acid, a protein serine-threonine phosphatase inhibitor (2 microM, 65% inhibition with or without AA); 3) the marine PLA2 inhibitor manoalide (1 microM, 97.5% inhibition without AA, 75% with AA). In addition, it was observed that exogenously added AA enhanced PMA-stimulated O2- generation in a time- and dose-dependent manner (5-50 microM) and partially reversed the inhibitory effect of manoalide. The following inhibitors did not block PMA-stimulated O2- generation in the absence or presence of AA: 1) indomethacin, a CO inhibitor (1-100 microM) and WY-50,295M tromethamine, a novel 5-LO inhibitor (1-100 microM); 2) genistein, a protein tyrosine kinase inhibitor (1-100 microM); and 3) sodium orthovanadate (1-300 microM), a protein tyrosine phosphatase inhibitor. It was concluded that, in in vivo LPS-primed Kupffer cells, PMA-stimulated O2- generation is modulated by PKC, protein serine-threonine phosphatase(s), PLA2 and AA but not by protein tyrosine kinase(s) and phosphatase(s) and CO and 5-LO products. These findings could have implications on the design of novel therapeutic approaches for the modulation of enhanced O2- release by Kupffer cells in endotoxemia.
authors.affiliation: Department of Physiology, Louisiana State University Medical Center, New Orleans.
authors.forename: A M
authors.initials: AM
authors.lastname: Mayer
authors.forename: J A
authors.initials: JA
authors.lastname: Spitzer
mesh_terms: D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D016718:Arachidonic Acid / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004988:Ethers, Cyclic / Q000494:pharmacology; D019833:Genistein; D066298:In Vitro Techniques; D007529:Isoflavones / Q000494:pharmacology; D007728:Kupffer Cells / Q000187:drug effects* / Q000201:enzymology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D019319:Okadaic Acid; D010741:Phospholipases A / Q000378:metabolism; D054467:Phospholipases A2; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D019311:Staurosporine; D013481:Superoxides / Q000378:metabolism*; D013729:Terpenes / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014638:Vanadates / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D004791:Enzyme Inhibitors; D004988:Ethers, Cyclic; D007529:Isoflavones; D008070:Lipopolysaccharides; D013729:Terpenes; D013481:Superoxides; D019319:Okadaic Acid; D016718:Arachidonic Acid; D014638:Vanadates; D019833:Genistein; C045673:manoalide; D001094:Arachidonate 5-Lipoxygenase; D011451:Prostaglandin-Endoperoxide Synthases; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C; D010741:Phospholipases A; D054467:Phospholipases A2; D010749:Phosphoprotein Phosphatases; D017027:Protein Tyrosine Phosphatases; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate