紫外线照射对浅表角质层细胞黑素的影响

Effect of UV irradiation on melanin in the superficial corneocytes

为了了解紫外线照射对浅表角质层细胞黑素含量和分布的影响，用紫外线照射１２名健康志愿者前臂内侧皮肤，分别于照射前后用透明粘附胶带取受试部位浅表角质层细胞。标本经ＦｏｎｔａｎａＭａｓｏｎ银氨液处理后，用ＯｐｔｏｍａｘⅤ型计算机成像分析系统测量和观察浅表角质层细胞中黑素含量和分布。结果，紫外线照射后１０ｍｉｎ，浅表角质层细胞中黑素含量与照射前比较无明显差异（Ｐ＞００５）；紫外线照射后１周，浅表角质层细胞黑素含量明显增加，与照射前比较有统计学差异（Ｐ＜００５）。同时观察到角质层细胞内黑素颗粒增大，颜色增深，黑素颗粒倾向集聚于细胞中心，形成帽状现象。本研究提示浅表角质层细胞对紫外线照射的黑素应答反应反映了人皮肤对日光紫外线幅射的自然保护。

To understand the changes of melanin content and distribution in the superficial corneocytes after UV exposure. Before and after UV irradiation,superficial corneocytes were taken from the inner side of forearm of 12 healthy volunteers using transparent adhesive tape. Samples were treated with Fontana Masson ammoniac silver nitrate . Melanin particles in the superficial corneocytes were assessed by Optomax Ⅴimage analyser. 10 minutes after UV irradiation, no much change of melanin content in the superficial corneocytes was observed(P >0 05) compared with those before UV exposure; one week later, there was a significant increase of melanin content in the cells (P< 0 05), with darker and larger melanin particles, which tended to be gathered at the centre of the cells, forming a cap like structure. It can be concluded that melanin changes in the superficial corneocytes in response to ultraviolet exposure indicate a natural protection from sunlight in human skin.