（生物谷Bioon.com）-來自英國一項最新研究稱,，由于人體不同部位皮膚對日曬的反應(yīng)不同,，要想曬出均勻的古銅色皮膚是一件較困難的事,。該研究報告發(fā)表在學(xué)術(shù)期刊《實驗皮膚病學(xué)》（Experimental Dermatology）上,。
夏天的陽光強烈,，那些喜歡日光浴的人因此獲得了將全身曬成古銅色的好機會,。
英國愛丁堡大學(xué)日前發(fā)布公告說，該校研究人員為研究日曬與皮膚癌之間的關(guān)系,，請100名志愿者接受了一定劑量的紫外線照射,。這種類似陽光的照射會引起皮膚兩種反應(yīng)，一種是短期的皮膚毛細(xì)血管充血帶來的紅色,，另一種就是皮膚生成黑色素而可以長期保留的古銅色,。
研究人員利用藥物抑制了毛細(xì)血管的充血反應(yīng)，然后對這些志愿者皮膚的顏色變化進(jìn)行了定量分析,，結(jié)果發(fā)現(xiàn),，臀部皮膚與背部皮膚對日曬的抵抗力相對更強，也就是說“上色”更少,。另外,，那些皮膚上有雀斑等斑點的人在日曬后皮膚更易變色。
領(lǐng)導(dǎo)研究的里斯教授說,，由日曬等原因引起的皮膚癌在身體不同部位的發(fā)病情況有很大差異,，他們希望能探清其中的原因，結(jié)果發(fā)現(xiàn)人體不同部位的皮膚對日曬有不同反應(yīng),，這也就意味著它們在日曬后將會出現(xiàn)不同的變色程度（黃堃）,。
生物谷推薦原文出處：
Experimental Dermatology DOI:10.1111/j.1600-0625.2010.01078.x
The physiological and phenotypic determinants of human tanning measured as change in skin colour following a single dose of ultraviolet B radiation
Terence H. Wong 1 , Ian J. Jackson 2 and Jonathan L. Rees 1
1 Department of Dermatology, University of Edinburgh, Edinburgh, UK ;
2 MRC Human Genetics Unit, Edinburgh, UK
Abstract: Experimental study of the in vivo kinetics of tanning in human skin has been limited by the difficulties in measuring changes in melanin pigmentation independent of the ultraviolet-induced changes in erythema. The present study attempted to experimentally circumvent this issue. We have studied erythemal and tanning responses following a single exposure to a range of doses of ultraviolet B irradiation on the buttock and the lower back in 98 subjects. Erythema was assessed using reflectance techniques at 24 h and tanning measured as the L* spectrophotometric score at 7 days following noradrenaline iontophoresis. We show that dose (P < 0.0001), body site (P < 0.0001), skin colour (P < 0.0001), ancestry (P = 0.0074), phototype (P = 0.0019) and sex (P = 0.04) are all independent predictors of erythema. Quantitative estimates of the effects of these variables are reported, but the effects of ancestry and phototype do not appear solely explainable in terms of L* score. Dose (P < 0.0001), body site (P < 0.0001) and skin colour (P = 0.0365) or, as an alternative to skin colour, skin type (P = 0.0193) predict tanning, with those with lighter skin tanning slightly more to a defined UVB dose. If erythema is factored into the regression, then only dose and body site remain significant predictors of tanning: therefore neither phototype nor pigmentary factors, such as baseline skin colour, or eye or hair colour, predict change in skin colour to a unit erythemal response.
