SKIN COLOR AND NUTRIENT PHOTOLYSIS - EVOLUTIONARY HYPOTHESIS
SKIN COLOR AND NUTRIENT PHOTOLYSIS - EVOLUTIONARY HYPOTHESIS
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DOI：
10.1126/science.675247
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发表时间：
1978-01-01
期刊：
影响因子：
56.9
通讯作者：
EATON, JW
中科院分区：
文献类型：
--
作者：
BRANDA, RF;EATON, JW
生活在阳光强烈地区的人群往往会有严重的黑化。以前对这种关系的解释只援引了微弱的选择压力。为了检验深色色素沉着可以防止关键的光敏维生素和代谢物被UV光光解的假设，叶酸被用作模型。结果发现，在体外暴露于模拟强烈的阳光下的人血浆导致30%至50%的损失叶酸在60分钟内。此外，皮肤浅的患者暴露于紫外线的皮肤疾病有异常低的血清叶酸浓度，这表明光解也可能发生在体内。叶酸缺乏症发生在许多营养不良的人群中，导致严重贫血、胎儿消瘦、明显不孕和产妇死亡。深色皮肤可以防止叶酸和其他光敏营养素的紫外线光解，这可能足以解释为什么在强烈太阳辐射地区的土著人群中保持这一特征。
Human populations native to areas of intense sunlight tend to be heavily melanized. Previous explanations for this relationship have invoked only weak selective pressures. To test the hypothesis that dark pigmentation may protect against photolysis of crucial light-sensitive vitamins and metabolites by UV light, folate was used as a model. It was found that exposure of human plasma in vitro to simulated strong sunlight causes 30 to 50 percent loss of folate within 60 min. Furthermore, light-skinned patients exposed to UV light for dermatologic disorders have abnormally low serum folate concentrations, suggesting that photolysis may also occur in vivo. Deficiency of folate, which occurs in many marginally nourished populations, causes severe anemia, fetal wastage, frank infertility and maternal mortality. Prevention of UV photolysis of folate and other light-sensitive nutrients by dark skin may be sufficient explanation for the maintenance of this characteristic in human groups indigenous to regions of intense solar radiation.