(生物谷Bioon.com)-来自英国一项最新研究称,由于人体不同部位皮肤对日晒的反应不同,要想晒出均匀的古铜色皮肤是一件较困难的事。该研究报告发表在学术期刊《实验皮肤病学》(Experimental Dermatology)上。
夏天的阳光强烈,那些喜欢日光浴的人因此获得了将全身晒成古铜色的好机会。
英国爱丁堡大学日前发布公告说,该校研究人员为研究日晒与皮肤癌之间的关系,请100名志愿者接受了一定剂量的紫外线照射。这种类似阳光的照射会引起皮肤两种反应,一种是短期的皮肤毛细血管充血带来的红色,另一种就是皮肤生成黑色素而可以长期保留的古铜色。
研究人员利用药物抑制了毛细血管的充血反应,然后对这些志愿者皮肤的颜色变化进行了定量分析,结果发现,臀部皮肤与背部皮肤对日晒的抵抗力相对更强,也就是说“上色”更少。另外,那些皮肤上有雀斑等斑点的人在日晒后皮肤更易变色。
领导研究的里斯教授说,由日晒等原因引起的皮肤癌在身体不同部位的发病情况有很大差异,他们希望能探清其中的原因,结果发现人体不同部位的皮肤对日晒有不同反应,这也就意味着它们在日晒后将会出现不同的变色程度(黄堃)。
生物谷推荐原文出处:
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.