MECHANISMS OF INDUCED TOLERANCE TO UV RADIATION IN SKIN

我们将使用定量技术来测量 正常皮肤对紫外线辐射的反应是遗传性黑素生成能力的函数， 紫外波段的函数。 我们将检查黑色素和 非黑色素机制。 这是我们第一次将 和体外光学测量， 针对表皮和真皮损伤的特定标记。 答复将 在不同遗传晒黑能力的个体中进行比较， 对不同波段（UVA和UVB）的响应。 紫外光诱导结构 离体表皮光传输的变化和改变， 角质层样品将被测量并与 对UVR损伤的耐受性的发展。 将通过以下方式评估耐受性： 测量红斑的程度，皮肤血液的结构损伤 血管，以及进一步紫外线导致的表皮DNA损伤 exposure. 这些研究将确定以下方面的相对重要性： 不同遗传因素受试者的不同保护机制 着色能力。 我们将确定高加索人是否 就其通过以下方式发展对UVR的耐受性的能力而言是异质的： 非黑色素机制，如果是，差异是否与或 取决于晒黑的能力 UVA暴露对 将在不同的皮肤类型中检查黑素细胞群， 长波引起的变化对诱导的功能性贡献 将检查光保护。

We will use quantitative techniques to measure the protective responses of normal skin to UVR as a function of heritable melanogenic capability and as a function of ultraviolet waveband. We will examine both melanin and non-melanin mechanisms. For the first time we will correlate structural and optical measurements in vitro with protection against erythema and against specific markers of epidermal and dermal damage. Responses will be compared in individuals of different genetic tanning capability and in response to different wavebands (UVA and UVB). UV-induced structural changes and alterations in optical transmissions by isolated epidermis and stratum corneum samples will be measured and correlated with the development of tolerance to insult by UVR. Tolerance will be assessed by measuring the degree of erythema, structural damage to dermal blood vessels, and damage to DNA in the epidermis resulting from further UV exposure. These studies will determine the relative importance of different protective mechanisms in subjects of different heritable pigmentation capabilities. We will determine whether Caucasians are heterogeneous with respect to their ability to develop tolerance to UVR by non-melanin mechanisms and, if so, whether differences correlate with or are dependent of tanning ability. The effects of UVA exposure upon melanocyte populations will be examined in different skin types, and the functional contribution of longwave induced changes to induced photoprotection will be examined.