5,6-dihydroxyindole-2-carboxylic acid, a diffusible melanin precursor, is a potent stimulator of lipopolysaccharide-induced production of nitric oxide by J774 macrophages

详细信息	查看全文 | 推荐本文 |

• 作者：D'Acquisto ; Fulvio ; Carnuccio ; Rosa ; d'Ischia ; Marco ; Misuraca ; Giovanna
• 关键词：5 ; 6-dihydroxyindole-2-carboxylic acid ; melanocyte activity ; immune system
• 刊名：Life Sciences
• 出版年：1995
• 期刊代码：62_00243205
• 类别：imm
• 出版时间：November 17, 1995
• 卷：57
• 期：26
• 页码：PL401-PL406
• 文件大小：418 K

摘要

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 concentrition of 1 × 10⁻⁶M, and is suppressed by the NOS inhibitor N^G-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.