The mechanisms of compound 48/80-induced superoxide generation mediated by A-kinase in rat peritoneal mast cells.
This investigation was undertaken to clarify the mechanisms of superoxide anion (O2-) generation in rat peritoneal mast cells. Compound 48/80, a typical histamine liberator mediated by calcium influx, elicited O2- generation from the mast cells in a dose-dependent fashion. It was demonstrated by immunohistochemical study and Western blot analysis that the mast cells contained the 47-kDa phagocyte oxidase (p47phox) protein, which was one cytosolic component of the NADPH oxidase system. Arachidonic acid stimulated O2- generation in the mast cells, but other unsaturated fatty acids had no effect. On the other hand, 48/80-induced O2- generation was inhibited by phospholipase A2 inhibitors, such as arachidonyl trifluoromethyl ketone and manoalide. Forskolin, isoprenaline, and dibutyryl cyclic AMP inhibited the O2- generation, and KT-5720, a cyclic AMP-dependent protein kinase (A-kinase) inhibitor, markedly enhanced the O2- generation. These findings suggest that O2- is generated by a NADPH oxidase-like enzyme system in mast cells and that this enzyme system is activated by arachidonic acid released by cytosolic phospholipase A2. Thus, it is regulated by the cyclic AMP-A kinase system.
Fukuishi
N
N
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tokushimabunnri University, Tokushima, Japan.
Sakaguchi
M
M
Matsuura
S
S
Nakagawa
C
C
Akagi
R
R
Akagi
M
M
D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology; D001095:Arachidonic Acids / Q000494:pharmacology; D015153:Blotting, Western; D003994:Bucladesine / Q000494:pharmacology; D002227:Carbazoles; D005576:Colforsin / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000187:drug effects* / Q000378:metabolism*; D006105:Granulomatous Disease, Chronic; D007150:Immunohistochemistry; D007211:Indoles / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008407:Mast Cells / Q000187:drug effects* / Q000378:metabolism*; D019255:NADPH Oxidases; D010750:Phosphoproteins / Q000737:chemistry / Q000276:immunology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011758:Pyrroles / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins; D013481:Superoxides / Q000378:metabolism*; D013729:Terpenes / Q000494:pharmacology; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology*
D001095:Arachidonic Acids; D002227:Carbazoles; D007211:Indoles; D010750:Phosphoproteins; D011758:Pyrroles; D011994:Recombinant Proteins; D013729:Terpenes; C081565:arachidonyltrifluoromethane; D013481:Superoxides; D005576:Colforsin; D016718:Arachidonic Acid; D003189:p-Methoxy-N-methylphenethylamine; C057416:KT 5720; D003994:Bucladesine; C045673:manoalide; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D007545:Isoproterenol