Effendy I, Kwangsukstith C, Lee J Y, Maibach H I
Department of Dermatology, University of Marburg, Germany.
Acta Derm Venereol. 1995 Nov;75(6):455-8. doi: 10.2340/0001555575455458.
The effects of topical glycolic acid and all-trans retinoic acid on stratum corneum barrier function and hydration of human skin were investigated in 6 healthy volunteers utilizing non-invasive techniques. In addition, changes in stratum corneum turnover time induced by the substances were examined using the dansyl chloride fluorescence test. Twelve percent glycolic acid in water and 0.1% retinoic acid in ethanol, respectively, were applied for 60 min once daily, over a period of 2 weeks (5 consecutive days weekly) on dansyl chloride-labelled skin and on untreated skin. During a 10-day application period, both glycolic acid and retinoic acid similarly induced a significant increase in TEWL. However, after discontinuing treatment, TEWL in retinoic acid-exposed skin remained increased. Glycolic acid significantly reduced stratum corneum hydration from day 11 to day 18 (p < 0.05), while retinoic acid induced skin dryness after 9 days of treatment, which persisted until day 18 (p < 0.005). Whereas glycolic acid rapidly induced an intense erythema implying a direct non-specific inflammatory response, the retinoic acid-exposed skin gradually developed erythema. Retinoic acid caused scaling to a greater extent than did glycolic acid, even after treatment cessation. Both glycolic acid and retinoic acid significantly decreased stratum corneum turnover time and stratum corneum turnover time50 (the time in days from labelling until approximately 50% of fluorescence disappeared), compared with the vehicle controls. However, glycolic acid shortened stratum corneum turnover time (12.8 +/- 0.9 days) as well as stratum corneum turnover time50 (7.3 +/- 0.7 d) significantly more than did retinoic acid (15.8 +/- 0.7 d and 9 +/- 0.8 d, respectively). While ethanol (vehicle of retinoic acid) slightly but significantly decreased stratum corneum turnover time (p < 0.05), water (vehicle of glycolic acid) did not. This study showed that both glycolic acid and retinoic acid induced certain functional changes in stratum corneum, mirroring their irritation potential. However, changes at retinoic acid-exposed sites appeared longer-lasting, implying a distinct mode of action. An increase in stratum corneum turnover induced by the substances may be, in part, linked with their irritation properties.
在6名健康志愿者中，利用非侵入性技术研究了局部应用乙醇酸和全反式维甲酸对人体皮肤角质层屏障功能和水合作用的影响。此外，使用丹磺酰氯荧光试验检测了这些物质诱导的角质层周转时间的变化。分别将12%的乙醇酸水溶液和0.1%的维甲酸乙醇溶液每天一次涂抹60分钟，持续2周（每周连续5天），涂抹在经丹磺酰氯标记的皮肤和未处理的皮肤上。在10天的涂抹期内，乙醇酸和维甲酸均同样显著增加了经皮水分流失（TEWL）。然而，停止治疗后，维甲酸处理的皮肤中的TEWL仍保持升高。从第11天到第18天，乙醇酸显著降低了角质层水合作用（p<0.05），而维甲酸处理9天后导致皮肤干燥，这种情况一直持续到第18天（p<0.005）。乙醇酸迅速引起强烈的红斑，这意味着直接的非特异性炎症反应，而维甲酸处理的皮肤逐渐出现红斑。即使在停止治疗后，维甲酸引起的脱屑程度也比乙醇酸更大。与赋形剂对照相比，乙醇酸和维甲酸均显著缩短了角质层周转时间和角质层周转时间50（从标记到约50%荧光消失的天数）。然而，乙醇酸对角质层周转时间（12.8±0.9天）和角质层周转时间50（7.3±0.7天）的缩短幅度明显大于维甲酸（分别为15.8±0.7天和9±0.8天）。虽然乙醇（维甲酸的赋形剂）轻微但显著缩短了角质层周转时间（p<0.05），而水（乙醇酸的赋形剂）则没有。这项研究表明，乙醇酸和维甲酸均诱导了角质层的某些功能变化，反映了它们的刺激潜能。然而，维甲酸处理部位的变化似乎持续时间更长，这意味着其作用方式不同。这些物质诱导的角质层周转增加可能部分与其刺激特性有关。
