title: Pharmacological comparison of LTB(4)-induced NADPH oxidase activation in adherent and non-adherent guinea-pig eosinophils.
abstract: 1. Leukotriene B(4) (LTB(4)) stimulation of guinea-pig peritoneal eosinophils, induced a biphasic activation of the NADPH oxidase composed of a rapid (<3 min) phase mediated by non-adherent cells and a sustained (3 - 120 min) phase mediated by CD11b/CD18 adherent eosinophils. Studies were undertaken to compare the intracellular mechanism that mediate these responses. 2. SB 203580 and PP1, inhibitors of p38 mitogen-activated protein (MAP) kinase and the src-family protein tyrosine kinases, respectively caused concentration-dependent attenuation of both the rapid (SB203580: pD(2)=-6.31; PP1: pD(2)=-5.50) and sustained (SB203580: pD(2)=-6.50; PP1: pD(2)=-5.73) phases. Similarly, the MAP kinase kinase-1 inhibitor, PD098059 produced partial inhibition of the both phases of superoxide generation. 3. The protein kinase C (PKC) inhibitors Ro-31 8220, GF 109203X and Gö 6976 attenuated the rapid NADPH oxidase response (pD(2)s=-6.10, -6.72, -6.15 respectively) and, to a lesser extent, (pD(2)s=-5.54, -6.02, -6.51 respectively) the sustained phase. 4. An inhibitor of phosphatidylinositol 3-kinase (PtdIns 3-kinase), wortmannin caused concentration dependent attenuation of the sustained (pD(2)=-8.68) but not rapid phase of superoxide generation. In contrast, the syk kinase inhibitor, piceatannol abolished the rapid (pD(2)=-6.43) but not sustained respiratory responses. 5. This study demonstrates that LTB(4)-induced superoxide generation from adherent and non-adherent eosinophils is mediated via both common (p38 MAP kinase, MEK-1, PKC and the src kinases) and divergent intracellular pathways (syk kinases and PtdIns 3-kinase). This suggests the possibility of therapeutic intervention to selective attenuate activation of adherent tissue eosinophils.
authors.affiliation: Thoracic Medicine, Imperial College School of Medicine at the National Heart and Lung Institute, Dovehouse Street, London, SW3 6LY.
authors.forename: O T
authors.initials: OT
authors.lastname: Lynch
authors.forename: M A
authors.initials: MA
authors.lastname: Giembycz
authors.forename: P J
authors.initials: PJ
authors.lastname: Barnes
authors.forename: M A
authors.initials: MA
authors.lastname: Lindsay
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D018821:CD18 Antigens / Q000276:immunology; D002227:Carbazoles / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors / Q000502:physiology; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D005419:Flavonoids / Q000494:pharmacology; D006168:Guinea Pigs; D007093:Imidazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D019012:Integrin beta1 / Q000276:immunology; D047908:Intracellular Signaling Peptides and Proteins; D007975:Leukotriene B4 / Q000494:pharmacology*; D016177:Macrophage-1 Antigen / Q000276:immunology; D008297:Male; D008301:Maleimides / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology; D019255:NADPH Oxidases / Q000187:drug effects* / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology; D011720:Pyrazoles / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D013267:Stilbenes / Q000494:pharmacology; D000072377:Syk Kinase; D013997:Time Factors; D000077191:Wortmannin; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000502:physiology
chemical_list: D000730:Androstadienes; D000906:Antibodies; D018821:CD18 Antigens; D002227:Carbazoles; D004791:Enzyme Inhibitors; D004792:Enzyme Precursors; D005419:Flavonoids; D007093:Imidazoles; D007211:Indoles; D019012:Integrin beta1; D047908:Intracellular Signaling Peptides and Proteins; D007975:Leukotriene B4; D016177:Macrophage-1 Antigen; D008301:Maleimides; D020928:Mitogen-Activated Protein Kinases; D019255:NADPH Oxidases; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011493:Protein Kinase C; D011505:Protein-Tyrosine Kinases; D011720:Pyrazoles; D011725:Pyridines; D011743:Pyrimidines; D013267:Stilbenes; D000072377:Syk Kinase; D000077191:Wortmannin; D019061:src-Family Kinases; C108123:4-amino-5-(4-methylphenyl)-7-(tert-butyl)pyrazolo(3,4-d)pyrimidine; C081021:Go 6976; C041525:3,3',4,5'-tetrahydroxystilbene; C000606898:Syk protein, rat; C070515:bisindolylmaleimide I; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; C064758:Ro 31-8220