5,6-Dihydroxyindole-2-carboxylic acid, a diffusible melanin precursor, is a potent stimulator of lipopolysaccharide-induced production of nitric oxide by J774 macrophages
| Autor: | Fulvio D'Acquisto, Marco d'Ischia, Giovanna Misuraca, Rosa Carnuccio |
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| Přispěvatelé: | D'Acquisto, Fulvio, Carnuccio, Rosa, D'Ischia, Marco, Misuraca, G. |
| Jazyk: | angličtina |
| Rok vydání: | 1995 |
| Předmět: |
Lipopolysaccharides
Indoles Lipopolysaccharide Stimulation Biology Arginine Nitric Oxide General Biochemistry Genetics and Molecular Biology Cell Line Nitric oxide Diffusion Melanin Mice chemistry.chemical_compound Biosynthesis Animals Enzyme Inhibitors Protein Precursors General Pharmacology Toxicology and Pharmaceutics Cells Cultured Melanins omega-N-Methylarginine Macrophages DHICA General Medicine Macrophage Activation Salmonella typhi Biochemistry chemistry Cell culture Melanocytes Omega-N-Methylarginine Nitric Oxide Synthase |
| Popis: | Pre-incubation of J774 murine macrophages with 5,6-dihydroxyindole-2-carboxylic acid (DHICA), a diffusible intermediate in the biosynthesis of eumelanins, leads to a marked increase in the levels of nitric oxide (NO) produced by lipopolysaccharide (LPS)-induced NO-synthase (iNOS). The effect varies with DHICA concentration being maximum at a concentration of 1 x 10(-6)M, and is suppressed by the NOS inhibitor NG-monomethyl-L-arginine (L-NMMA). No stimulation is observed when macrophages are exposed to DHICA after activation with LPS, indicating that the indole does not affect the catalytic activity of iNOS. These results point to a hitherto unrecognized role of DHICA as a chemical messenger mediating interaction between active melanocytes and macrophages in epidermal inflammatory and immune responses. |
| Databáze: | OpenAIRE |
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