Sato J, Denda M, Ashida Y, Koyama J
Shiseido Research Center, Yokohama, Japan.
Arch Dermatol Res. 1998 Nov;290(11):634-7. doi: 10.1007/s004030050364.
Many clinical studies have shown that low humidity has a deleterious effect on skin, but the mechanisms involved are poorly understood. To clarify the changes that occur in skin, we examined epidermal cell proliferation in mice kept in a dry (relative humidity < 10%) or a moist (relative humidity > 90%) environment. In animals exposed to low humidity, epidermal DNA synthesis started to increase within 12 h, reaching twice the original level, and the increased level was maintained for up to 5 days. The transepidermal water loss (TEWL) of mice kept for 12 h in the dry environment was the same as that of mice kept in the moist environment, but the skin conductance was lower. The increase in epidermal DNA synthesis following exposure to the dry environment was inhibited by topical application of petrolatum. It is concluded that loss of water from the stratum corneum induces epidermal cell proliferation within 12 h, and this change occurs in the absence of apparent cutaneous barrier dysfunction.
许多临床研究表明，低湿度会对皮肤产生有害影响，但其中涉及的机制尚不清楚。为了阐明皮肤发生的变化，我们检测了饲养在干燥（相对湿度<10%）或潮湿（相对湿度>90%）环境中的小鼠的表皮细胞增殖情况。在暴露于低湿度环境的动物中，表皮DNA合成在12小时内开始增加，达到原来水平的两倍，并且增加的水平持续维持长达5天。在干燥环境中饲养12小时的小鼠的经表皮水分流失（TEWL）与在潮湿环境中饲养的小鼠相同，但皮肤电导较低。局部涂抹凡士林可抑制暴露于干燥环境后表皮DNA合成的增加。得出的结论是，角质层水分流失会在12小时内诱导表皮细胞增殖，并且这种变化在没有明显皮肤屏障功能障碍的情况下发生。
