Pawelek J M, Chakraborty A K, Osber M P, Orlow S J, Min K K, Rosenzweig K E, Bolognia J L
Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut 06510.
Pigment Cell Res. 1992 Nov;5(5 Pt 2):348-56. doi: 10.1111/j.1600-0749.1992.tb00561.x.
When human skin is exposed to ultraviolet (UV) light, a highly complex cascade of events ensues that culminates, among other things, in increased skin melanin content. From analyses at the tissue and cellular level, it has been shown that following exposure to UV light there is an increase in the number of active melanocytes in the basal layer of the epidermis, and individual melanocytes are stimulated to produce more melanin. In addition, the rate of transfer of melanosomes from melanocytes to keratinocytes is apparently increased, although the role of UV light in this process remains to be demonstrated. Recent biochemical evidence is reviewed on factors that regulate these processes. A plausible explanation for the effects of UV on pigmentation is that there are mechanisms in the skin for the orderly, regulated reception of UV signals that are then transduced to initiate the cascade. The signals involve both melanocytes and keratinocytes, and available evidence supports a model in which melanotropins and their receptors play a central role in the process.
当人体皮肤暴露于紫外线（UV）下时，会引发一系列高度复杂的事件，最终除其他影响外，会使皮肤黑色素含量增加。从组织和细胞水平的分析表明，暴露于紫外线后，表皮基底层中活跃黑素细胞的数量会增加，并且单个黑素细胞会受到刺激产生更多的黑色素。此外，黑素小体从黑素细胞向角质形成细胞的转移速率明显增加，尽管紫外线在这一过程中的作用仍有待证实。本文综述了关于调节这些过程的因素的最新生化证据。紫外线对色素沉着影响的一个合理的解释是，皮肤中存在用于有序、调节接收紫外线信号的机制，这些信号随后被转导以启动级联反应。这些信号涉及黑素细胞和角质形成细胞，现有证据支持一种模型，其中促黑素及其受体在该过程中起核心作用。
