DIFFERENTIAL ANALYSIS OF EXPERIMENTAL HYPERMELANOSIS INDUCED BY UVB, PUVA, AND ALLERGIC CONTACT-DERMATITIS USING A BROWNISH GUINEA-PIG MODEL
DIFFERENTIAL ANALYSIS OF EXPERIMENTAL HYPERMELANOSIS INDUCED BY UVB, PUVA, AND ALLERGIC CONTACT-DERMATITIS USING A BROWNISH GUINEA-PIG MODEL
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DOI：
10.1007/bf00418162
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发表时间：
1986-01-01
影响因子：
3
通讯作者：
MOTEGI, I
中科院分区：
文献类型：
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作者：
IMOKAWA, G;KAWAI, M;MOTEGI, I
在中度着色的豚鼠皮肤中，UVB、PUVA和过敏性接触性皮炎可诱导色素沉着过度，类似于在蒙古人皮肤中观察到的色素沉着变化。使用这个模型，我们研究了化学试剂，包括酪氨酸酶抑制剂和防晒剂，对紫外线照射引起的颜色变化的影响。将褐色豚鼠皮肤每天暴露于各种能量的UVB照射连续3天，在照射的几天内在侧面的照射矩形区域上诱导清晰可见的黑色色素沉着，在照射后约1周达到最大值，即，类似于有色人类皮肤中发生的变化。由未处理的有色豚鼠制备的分裂表皮片显示200-400个黑素细胞/mm 2; UV照射后1周，应用区域显示具有粗壮树突的强多巴阳性黑素细胞数量增加（800- 1，000个细胞/mm 2）。UVA照射后腹腔注射8-甲氧基补骨脂素（8-MOP）也产生黑色色素沉着照射后1周，这是由多巴反应分裂表皮片中多巴阳性黑素细胞的数量显着增加。过敏性接触性皮炎产生的应用1-苯基偶氮-2-萘酚诱导色素沉着过度后，间隔约14天，在10的21个过敏获得动物检查。与对照组相比，这种诱导的色素沉着伴随着多巴阳性黑素细胞数量的增加。相比之下，过敏性接触性皮炎的应用二硝基氯苯未能诱导这样高的比例postpigmentation，只有3的21只过敏获得的动物表现出色素沉着过度和5表现出色素脱失，在后者中，多巴阳性黑素细胞的数量略有减少。为了研究酪氨酸抑制剂对UVB诱导的色素沉着的预防作用，在每日三次UVB照射后进行这些化合物的每日局部应用。用10%对苯二酚处理10天中断UVB诱导的色素沉着，并导致表皮黑素细胞的数量显着减少相比，在UVB照射，未经处理的对照皮肤中发现的数量。
In moderately colored guinea-pig skin, UVB, PUVA, and allergic contact dermatitis were shown to induce hyperpigmentation that resembled the pigmentary changes observed in mongoloid human skin. Using this model, we examined the effects of chemical agents, including tyrosinase inhibitors and sunscreen agents, on the color changes induced by UV irradiation. The daily exposure of brownish guinea-pig skin to UVB irradiation at a variety of energies for 3 successive days induced clearly visible black pigmentation on the irradiated rectangular areas of the flank within a few days of irradiation, the maximum being reached about 1 week after irradiation, i.e., similar to the changes that occur in pigmented human skin. Split epidermal sheets prepared from untreated pigmented guinea pigs exhibited 200-400 melanocytes/mm2; 1 week after UV irradiation, the applied areas show an increased number of strongly dopa-positive melanocytes with stout dendrites (800-1,000 cells/mm2). UVA irradiation following an intraperitoneal injection of 8-methoxypsoralen (8-MOP) also produced black pigmentation 1 week after irradiation, and this was paralleled by a marked increase in the number of dopa-positive melanocytes in dopa-reacted split epidermal sheets. Allergic contact dermatitis produced by the application of 1-phenylazo-2-naphtol induced hyperpigmentation after an interval of about 14 days in 10 of the 21 allergy-acquiring animals examined. This induced pigmentation was accompanied by an increase in the number of dopa-positive melanocytes as compared to the number seen in controls. In contrast, allergic contact dermatitis produced by the application of dinitrochlorobenzene failed to induce such a high ratio of postpigmentation, with only 3 of the 21 allergy-acquiring animals showing hyperpigmentation and 5 showing depigmentation; in the latter, there was a slight decrease in the number of dopa-positive melanocytes. To study the preventive effect of tyrosine inhibitors on UVB-induced pigmentation, daily topical applications of these compounds were performed after three daily UVB irradiations. Treatment with 10% hydroquinone for 10 days interrupted UBV-induced pigmentation and resulted in a marked reduction in the number of epidermal melanocytes as compared to the number found in UVB-irradiated, untreated control skin.