Effects of ultraviolet A and B on the skin barrier: a functional, electron microscopic and lipid biochemical study.
To investigate the effects of ultraviolet A (UVA) and B (UVB) on the skin barrier, functional, electron microscopic and lipid biochemical studies were performed on normal and UV-irradiated skin of volunteers. Skin reactivity against primary irritants was evaluated using the alkali resistance test, the dimethylsulfoxide test and the sodium lauryl sulfate test. In all 3 irritation models, UVA- and UVB-irradiated areas were more resistant to damage than normal skin, indicating improvement of the barrier function after UV irradiation. In a second series of experiments, biopsies were taken and processed for electron microscopic evaluation of the stratum corneum. UVB significantly increased the horny cell layers; UVA did not alter the thickness of the stratum corneum. Finally, stratum corneum lipids were extracted in vivo and quantified after high-performance thin-layer chromatography. UVB and, to some extent, UVA exposure increased the amount of all stratum corneum lipids. This was also observed in all major ceramide subfractions.
Lehmann
P
P
Department of Dermatology, Heinrich-Heine University, Düsseldorf, Germany.
Hölzle
E
E
Melnik
B
B
Plewig
G
G
D000293:Adolescent; D000328:Adult; D000468:Alkalies; D006801:Humans; D007509:Irritants / Q000494:pharmacology; D008055:Lipids / Q000032:analysis*; D011701:PUVA Therapy; D012867:Skin / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects* / Q000648:ultrastructure; D014466:Ultraviolet Rays
D000468:Alkalies; D007509:Irritants; D008055:Lipids