THE FUNCTION OF MELANIN OR 6 BLIND PEOPLE EXAMINE AN ELEPHANT
THE FUNCTION OF MELANIN OR 6 BLIND PEOPLE EXAMINE AN ELEPHANT
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DOI：
10.1002/bies.950140111
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发表时间：
1992-01-01
期刊：
影响因子：
4
通讯作者：
HILL, HZ
中科院分区：
文献类型：
--
作者：
HILL, HZ
黑色素存在于所有有生命的王国以及许多不同的结构和形式中。当它的各种功能被分开考察时，它的行为似乎是不同的和相互冲突的。它在伪装和性展示方面有明显的作用。其他主要角色也受到了批判性的审视。它可以起到防晒的作用，但效果不是很好。它也可以清除活性化学物质，但这也不是很有效。它会产生能破坏DNA的活性自由基。它以有益或有害的方式与药物结合。除了伪装，它的其他作用可以通过一个统一的假设结合在一起，这个假设是由Proctor和McGinness在近20年前首次提出的。黑色素被认为是一种具有非晶态半导体特性的能量转换器。它可以吸收许多不同类型的能量，并以热的形式将它们散失。然而，如果能量输入太大，输出可以表现为激活的化学物种的形式，这些化学物种可以破坏细胞大分子，导致细胞死亡、突变和癌症。黑色素在深色皮肤中的保护作用被认为是因为它的高浓度，以及它被限制在椭圆形和密集排列的细胞器中，这些细胞器可以有效地保护细胞核。在浅色皮肤中，它的激进性质被视为潜在地参与了致癌过程，特别是在被强烈的晒伤事件压倒时。
The pigment melanin is found in all living kingdoms and in many different structures and forms. When its various functions are examined separately, its behaviors seem disparate and conflicting. It has a clear role in camouflage and sexual display. Other major roles are examined critically. It can act as a sun screen but is not a very effective one. It can also scavenge active chemical species, but this, too, is not done very effectively. It produces active radicals that can damage DNA. It binds to drugs in ways that are either beneficial or deleterious. Aside from camouflage, its other roles can be brought together by a unifying hypothesis as first proposed by Proctor and McGinness nearly 20 years ago. Melanin is envisaged as an energy transducer with the properties of an amorphous semiconductor. It can absorb many different types of energy and dissipate them in the form of heat. However, if the energy input is too great, the output can be expressed in the form of activated chemical species that can damage cellular macromolecules resulting in cell death, mutations and cancer. The protective aspect of melanin in dark skin is seen as resulting from its high concentration and its confinement to ellipsoidal and densely packed organelles that can effectively shield the nucleus. In light skin, its radical nature is seen as potentially participating in the carcinogenic process, particularly when overwhelmed by intense episodes of sunburn.