Urocanic Acid Concentration and Photoisomerization in Caucasian Skin Phototypes
— To investigate the relationship between erythemal sensitivity of the skin to U V radiation and epidermal urocanic acid (UCA) concentration, 45 healthy volunteers of anamnestic skin phototypes (ASP) I‐IV were studied. In 16 of the subjects, we analyzed UCA photoisomerization after graded UVB exposu...
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Published in | Photochemistry and photobiology Vol. 65; no. 5; pp. 862 - 865 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Blackwell Publishing Ltd
01.05.1997
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Subjects | |
Online Access | Get full text |
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Summary: | — To investigate the relationship between erythemal sensitivity of the skin to U V radiation and epidermal urocanic acid (UCA) concentration, 45 healthy volunteers of anamnestic skin phototypes (ASP) I‐IV were studied. In 16 of the subjects, we analyzed UCA photoisomerization after graded UVB exposures. The median and mean total UCA concentration in unirradiated skin was 22.4 and 35.3 nmol/cm2, and no statistically significant difference in total UCA concentrations was detectable either between ASP I through II and III through IV or between the phototested skin type (PSP) groups 1 through 2 and 3 through 4. The relative amount of the cis‐isomer varied between 3 and 35%, with median and mean values of 7 and 12%, respectively. No statistically significant difference in absolute or relative cis‐UCA concentrations was detectable between ASP I through II and III through IV, but a significantly lower absolute (P < 0.009) and relative (P < 0.002) cis‐UCA concentration in unirradiated skin was recorded in PSP groups 1 through 2, compared to types 3 through 4. In all tested subjects, an erythemally weighted dose of 1 mj/cm2sufficed to cause trans‐ to cis‐UCA isomerization. When comparing photosensitive (skin phototype I) and phototolerant (phototypes III and IV) individuals, who were irradiated with a reference 5 mJ/cm2UV dose or with fractions of 0.1‐1.0 of their individual minimal erythema dose values, no skin phototype‐dependent difference in ability to photoisomerize was discernible. |
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Bibliography: | ark:/67375/WNG-FWMFG94J-D ArticleID:PHP862 istex:20F8C7BE2FA94D7B5903CEF3489C253F95C0079D ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0031-8655 1751-1097 |
DOI: | 10.1111/j.1751-1097.1997.tb01935.x |