McKenzie Roderick C, Beckett Geoff J, McLean Steven, Arthur John R, Macve Joanna C, Nicol Fergus, Howie A Forbes, Norval Mary
The Epidermal Infection and Protection Group, Laboratory for Clinical and Molecular Virology, University of Edinburgh, Edinburgh, Scotland.
Biol Trace Elem Res. 2008 Dec;125(3):255-67. doi: 10.1007/s12011-008-8171-2. Epub 2008 Jun 24.
The effect of three different doses of dietary L-selenomethionine (SM) and sodium selenite (SS) on skin selenium (Se) content, glutathione peroxidase (GPx) activity, Langerhans cell (LC) and mast cell numbers in ultraviolet radiation-B (UVB)-irradiated and unirradiated C3H/HeN mice was determined. After weaning, groups of mice were given Se-deficient, Se-adequate, or Se-high diets. Six weeks later, some animals in each group were exposed to a single UVB dose (acute), while others were exposed three times weekly for the following 40 weeks (chronic). The skin Se content and GPx activity increased in all the Se-supplemented groups, and the latter was not altered by UVB exposure. Generally, the Se-containing diets caused an increase in LC numbers at 6 weeks and a further rise at 40 weeks, but did not prevent the loss induced by acute or chronic UVB radiation. Skin mast cell numbers were highest in animals fed the Se-deficient diet after 6 and 40 weeks. Acute and chronic UVB radiation decreased the mast cell number and dietary Se did not prevent the reduction. While the present study shows that Se plays an important role in governing the number of LCs and mast cells in the skin, no protective effect against the immunomodulating properties of UVB radiation on these cell types was observed. However, this conclusion may only apply to the experimental conditions chosen, and additional studies at different Se dosages and reduced intensities of chronic UVB exposure are required to confirm the results.
测定了三种不同剂量的膳食L-硒代蛋氨酸（SM）和亚硒酸钠（SS）对紫外线B（UVB）照射和未照射的C3H/HeN小鼠皮肤硒（Se）含量、谷胱甘肽过氧化物酶（GPx）活性、朗格汉斯细胞（LC）和肥大细胞数量的影响。断奶后，将小鼠分组给予缺硒、富硒或高硒饮食。六周后，每组中的一些动物接受单次UVB照射（急性），而其他动物在接下来的40周内每周接受三次照射（慢性）。所有补硒组的皮肤Se含量和GPx活性均增加，且后者不受UVB照射的影响。一般来说，含硒饮食在6周时导致LC数量增加，在40周时进一步上升，但不能防止急性或慢性UVB辐射引起的LC数量减少。在6周和40周后，饲喂缺硒饮食的动物皮肤肥大细胞数量最高。急性和慢性UVB辐射均降低了肥大细胞数量，膳食硒不能防止这种减少。虽然本研究表明硒在控制皮肤中LC和肥大细胞数量方面起重要作用，但未观察到对UVB辐射对这些细胞类型的免疫调节特性的保护作用。然而，这一结论可能仅适用于所选择的实验条件，需要在不同硒剂量和降低的慢性UVB照射强度下进行额外研究以证实结果。
