ABSORPTION MECHANISMS OF HUMAN MELANIN IN THE VISIBLE, 400-720 NM
ABSORPTION MECHANISMS OF HUMAN MELANIN IN THE VISIBLE, 400-720 NM
复制标题
DOI：
10.1111/1523-1747.ep12471764
复制
发表时间：
1987-10-01
影响因子：
6.5
通讯作者：
BAQER, AH
中科院分区：
文献类型：
--
作者：
KOLLIAS, N;BAQER, AH
在本文中，我们提出，人类黑色素通过两种不同的机制吸收可见光辐射：一种是在整个可见光范围内有效，波长是线性的，第二种是在400-500 nm范围内的波长明显，频率是指数的。这些机制在我们收集的所有人体漫反射光谱中都很明显。我们表明，吸收剂是相同的，在所有人类志愿者的皮肤样本。通过研究溶液中的多巴-黑色素和粉末形式的多巴-黑色素的漫反射光谱，我们发现，我们可以关联的吸收机制，一个与溶液中的黑色素（低分子量形式），另一个与粉末中的黑色素（高分子量形式）。因此，我们提出黑色素以两种不同的状态存在。该模型具有生物学意义，因为它为从延迟色素（UVB诱导）和即时色素（UVA诱导）获得的漫反射光谱提供了合理的解释。延迟色素表现为两种形式的黑色素增加（新黑色素生成），而立即色素表现为较高分子量形式的增加，而较低分子量形式的相应减少：这两种机制的变化彼此独立。最后，我们表明，我们可以区分光谱之间的延迟色素和即时色素。
In this paper we propose that human melanin absorbs visible radiation through two distinct mechanisms: one that is in effect over the entire visible range and is linear in wavelength, and a second one that is evident at wavelengths in the range 400-500 nm and is exponential in frequency. These mechanisms are apparent in all human diffuse reflectance spectra that we have collected. We show that the absorber is the same in all human volunteer skin samples. By studying the diffuse reflection spectra of DOPA-melanin in solution and DOPA-melanin in powder form, we find that we can correlate the absorption mechanisms, one with melanin in solution (a low molecular weight form) and the other with melanin in power (a high molecular weight form). Therefore, we propose that melanin exists in two distinct states. This model is of biologic significance, as it provides a reasonable interpretation for the diffuse reflection spectra obtained from delayed pigment (UVB-induced) and immediate pigment (UVA-induced). Delayed pigment appears as an increase of both forms of melanin (neomelanogenesis), whereas immediate pigment appears as an increase in the higher molecular weight form with a commensurate decrease in the lower molecular weight form: the two mechanisms change independently of each other. Finally, we show that we can distinguish spectroscopically between the delayed pigment and the immediate pigment.