Cytotoxic effects of peroxynitrite, polymorphonuclear neutrophils, free-radical scavengers, inhibitors of myeloperoxidase, and inhibitors of nitric oxide synthase on bovine mammary secretory epithelial cells
| Autor: | Larry W. Douglass, Max Paape, Tonya K. Ledbetter |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Lipopolysaccharides
Neutrophils Blotting Western Nitric Oxide Antioxidants Neutrophil Activation Superoxide dismutase chemistry.chemical_compound Mammary Glands Animal Animals Histidine Tyrosine Enzyme Inhibitors Cytotoxicity Peroxidase Aniline Compounds Nitrates omega-N-Methylarginine General Veterinary biology Cell Death L-Lactate Dehydrogenase Chemistry Superoxide Dismutase Nitrotyrosine Epithelial Cells General Medicine Free Radical Scavengers Oxidants Nitric oxide synthase Biochemistry Myeloperoxidase Molsidomine biology.protein Phorbol Tetradecanoylphorbol Acetate Cattle Female Nitric Oxide Synthase Peroxynitrite |
| Zdroj: | American journal of veterinary research. 62(3) |
| ISSN: | 0002-9645 |
| Popis: | Objective—To determine cytotoxic effects of activated polymorphonuclear neutrophils (PMN) and peroxynitrite on bovine mammary secretory epithelial cells before and after addition of nitric oxide synthase inhibitors, myeloperoxidase (MPO) inhibitors, and free-radical scavengers. Sample Population—Polymorphonuclear neutrophils from 3 lactating cows. Procedure—Cells from the bovine mammary epithelial cell line MAC-T were cultured. Monolayers were treated with activated bovine PMN, lipopolysaccharide (LPS), phorbol 12-myristate 13-acetate (PMA), 3-morpholino- sydnonimine (SIN-1), 4-amino-benzoic acid hydrazide (ABAH), NG-monomethyl-L-arginine, histidine, and superoxide dismutase (SOD). At 24 hours, activity of lactate dehydrogenase in culture medium was used as a relative index of cell death. Tyrosine nitration of proteins in MAC-T cell lysates was determined by visual examination of immunoblots. Results—Lipopolysaccharide, PMA, and ≤ 0.1 mM SIN-1 were not toxic to MAC-T cells. Activated PMN, ≥ 6 mg of histidine/ml, and 0.5 mM SIN-1 were toxic. Together, histidine and 500,000 activated PMN/ml also were toxic. NG-monomethyl-L-arginine did not have an effect, but ABAH decreased PMN-mediated cytotoxicity. Ten and 50 U of SOD/ml protected MACT cells from cytotoxic effects of 0.5 mM SIN-1. Compared with control samples, nitration of MAC-T tyrosine residues decreased after addition of 500,000 PMN/ml or ≥ 6 mg of histidine/ml. Superoxide dismutase increased and SIN-1 decreased tyrosine nitration of MAC-T cell proteins in a dose-responsive manner. Conclusions and Clinical Relevance—Peroxynitrite, MPO, and histidine are toxic to mammary secretory epithelial cells. Superoxide dismutase and inhibition of MPO activity mitigate these effects. Nitration of MAC-T cell tyrosine residues may be positively associated with viability. (Am J Vet Res 2001;62:286–293) |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|