title: Endogenous nitric oxide limits cytokine-induced damage of murine lung epithelial cells.
abstract: This study investigated whether endogenous nitric oxide (NO) limits cytokine-induced damage to the murine lung epithelial cell line LA-4. NO production was assessed as nitrite using the Griess reaction, and cell damage was assessed using ethidium homodimer-1. Cytotoxicity was first detected after a 24-h incubation with a combination of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma (cytomix). Nitrite production increased to 78.0 +/- 0.5 nmol/10(6) cells at 24 h. Coincubation of LA-4 with cytomix and NO synthase inhibitors, aminoguanidine (3-1,000 microM) and N(G)-monomethyl-L-arginine (10-1,000 microM), but not N(G)-monomethyl-D-arginine, or a soluble guanylate cyclase inhibitor, 1H-[1,2,4] oxadiazole [4,3-a] quinoxalin-1-one, reduced cytomix-induced nitrite production and increased cytotoxicity up to twofold (24 h). Removal of L-arginine from the medium increased damage; reintroduction of 1,000 microM L-arginine, but not D-arginine, reversed this. In aminoguanidine-treated cells, replacement of NO with an NO donor, S-nitrosoglutathione (30 microM), reversed, in part, the cell damage observed in aminoguanidine/cytomix-treated cells. These results suggest that endogenous NO limits cytokine-induced lung epithelial damage.
authors.affiliation: Applied Pharmacology, Imperial College School of Medicine at the National Heart and Lung Institute, London, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Burke-Gaffney
authors.forename: P G
authors.initials: PG
authors.lastname: Hellewell
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology; D016207:Cytokines / Q000494:pharmacology*; D004338:Drug Combinations; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D004996:Ethidium / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D005978:Glutathione / Q000031:analogs & derivatives / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D051379:Mice; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009573:Nitrites / Q000378:metabolism; D009603:Nitroso Compounds / Q000494:pharmacology; D010069:Oxadiazoles / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D026422:S-Nitrosoglutathione; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D016207:Cytokines; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D007375:Interleukin-1; D009573:Nitrites; D009603:Nitroso Compounds; D010069:Oxadiazoles; D011810:Quinoxalines; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; C018533:ethidium homodimer; D007371:Interferon-gamma; D001120:Arginine; D019001:Nitric Oxide Synthase; D006162:Guanylate Cyclase; D004996:Ethidium; D005978:Glutathione