Gilchrest B A, Szabo G, Flynn E, Goldwyn R M
J Invest Dermatol. 1983 Jun;80 Suppl:81s-85s.
Clinical and histologic stigmata of aging are much more prominent in habitually sun-exposed skin than in sun-protected skin, but other possible manifestations of actinically induced aging are almost unexplored. We have examined the interrelation of chronologic and actinic aging using paired preauricular (sun-exposed) and postauricular (sun-protected) skin specimens. Keratinocyte cultures derived from sun-exposed skin consistently had a shorter in vitro lifespan but increased plating efficiency compared with cultures derived from adjacent sun-protected skin of the same individual, confirming a previous study of different paired body sites. Electron microscopic histologic sections revealed focal abnormalities of keratinocyte proliferation and alignment in vitro especially in those cultures derived from sun-exposed skin and decreased intercellular contact in stratified colonies at late passage, regardless of donor site. One-micron histologic sections of the original biopsy specimens revealed no striking site-related keratinocyte alterations, but sun-exposed specimens had fewer epidermal Langerhans cells (p less than 0.001), averaging approximately 50 percent the number in sun-protected skin, a possible exaggeration of the previously reported age-associated decrease in this cell population. These data suggest that sun exposure indeed accelerates aging by several criteria and that, regardless of mechanism, environmental factors may adversely affect the appearance and function of aging skin in ways amenable to experimental quantitation.
衰老的临床和组织学特征在习惯性暴露于阳光下的皮肤中比在防晒皮肤中更为显著，但光化诱导衰老的其他可能表现几乎未被探索。我们使用配对的耳前（暴露于阳光下）和耳后（防晒）皮肤标本，研究了自然衰老和光化衰老之间的相互关系。与来自同一个体相邻的防晒皮肤的培养物相比，来自暴露于阳光下皮肤的角质形成细胞培养物在体外的寿命始终较短，但接种效率有所提高，这证实了先前对不同配对身体部位的研究。电子显微镜组织学切片显示，体外角质形成细胞增殖和排列存在局灶性异常，尤其是来自暴露于阳光下皮肤的培养物，并且在传代后期分层菌落中的细胞间接触减少，与供体部位无关。原始活检标本的1微米组织学切片未显示出与部位相关的角质形成细胞有明显改变，但暴露于阳光下的标本中表皮朗格汉斯细胞较少（p小于0.001），平均约为防晒皮肤中细胞数量的50%，这可能夸大了先前报道的该细胞群体与年龄相关的减少。这些数据表明，从几个标准来看，阳光照射确实会加速衰老，而且无论机制如何，环境因素可能会以适合实验定量的方式对衰老皮肤的外观和功能产生不利影响。
