中波高能紫外线诱导豚鼠皮肤色素沉着改变的实验研究  

Targeted ultraviolet B （UVB） phototherapy induces skin hyperpigmentation in guinea pigs

作　　者：边胜男[1] 杨秀莉[1] 张敏[1] 

机构地区：[1]山东大学附属济南市中心医院皮肤科,济南250013

出　　处：《中华皮肤科杂志》2011年第7期483-486,共4页Chinese Journal of Dermatology

摘　　要：目的观察中波高能紫外线对皮肤色素沉着的诱导作用及其色素增加的作用机制。方法以正常棕黄色豚鼠皮肤为实验模型，在其背部脱毛处理后，取4个相邻的区域依次作为对照组和低、中、高剂量中波高能紫外线照射组，分别采用肉眼评估、黑素细胞染色（Imokawa法）以及黑素颗粒染色（Masson-Fontana法）方法，研究中波高能紫外线所致色素沉着作用；应用免疫组化染色法对不同照射剂量组豚鼠皮肤中的一氧化氮合酶（NOS）进行检测；HE染色观察表皮组织学改变。结果各照射组均出现不同程度的色素沉着，除中、高剂量组色素沉着评分结果差异无统计学意义外，其余各组的色素沉着评分平均黑素数量以及多巴阳性黑素细胞数之间的差异均具有统计学意义（P〈0．05），且中剂量组结果高于高剂量组。诱导型NOS的表达呈照射剂量依赖式递增，对照组和低、中、高剂量组诱导型NOS含量评分中位数分别为0，50、1．25、1．75、2．00，组间差异具有统计学意义（P〈0．05）。结论中波高能紫外线可诱导豚鼠皮肤色素增加，且这种效应有一定的剂量依赖性，但并非剂量越高越好。短期内接受中波高能紫外线照射是安全有效的。Objective To study the inductive effect of targeted UVB phototherapy on skin hyperpigmentation and its mechanism. Methods Ten brownish guinea pigs were used to develop experimental models. After depilation, four adjacent areas were selected on the back of each guinea pigs and seIved as the control, low-dose, moderate-dose and high-dose group to receive targeted UVB irradiation with a cumulative dose of 0, 2500, 3500, 4500 mJ/cm^2, respectively. After 6-week irradiation, the guinea pigs were sacrificed and skin samples were obtained. The hyperpigmentation induced by UVB irradiation was estimated by naked eyes, staining for melanocytes （Imokawa method） and melanin granules （Masson-Fontana staining）, respectively. Immunohistochemistry was carried out to determine the level of nitric oxide synthase and HE staining to observe epidermal histological changes. Results A statistical difference was observed in the pigmentation score, quantity of melanin granules and dopa-positive melanocyte number among the four groups （P 〈 0.05）, and the moderate- dose group was higher than the high-dose group in terms of these parameters. The expression of inducible nitric oxide synthase increased in a radiation dose-dependent manner, and the median value for inducible nitric oxide synthase expression level was 0.50, 1.25, 1.75, 2.00 in the control, low-dose, moderate-dose and high- dose group, respectively （P 〈 0.05）. Conclusions Targeted UVB phototherapy can induce hyperpigmentation of the skin in brownish guinea pigs in a dose-dependent manner, but higher dose may not work better. To irradiate with an initial dose close to or slightly higher than the minimum erythema dose may result in a satisfactory effect with reduced cumulative dose and potential risk for cancer.

关 键 词：紫外线疗法 皮肤色素沉着 辐射损伤 实验性 一氧化氮合酶 

分 类 号：R758.4[医药卫生—皮肤病学与性病学]