title: The contributions of UVA and UVB to connective tissue damage in hairless mice.
abstract: UVA, in high-dose single exposures, can, like UVB, be deleterious to skin. Dermal damage resulting from chronic exposure to UVA has not been studied. To investigate the long-term effects, we irradiated albino hairless mice for 30-34 weeks with UVA radiation, alone, from two sources with differing spectral qualities, and in combination with UVB as solar-simulating radiation. The results were compared to UVB alone. Like UVB, the UVA waveband, especially that with a spectral distribution similar to solar UVA, caused elastic fiber damage, increased glycosaminoglycan levels, and produced hypertrophy of deep dermal tissues. There were, however, striking differences between UVB- and UVA-irradiated skin. A combination of UVA and UVB summated the effects of both wavebands. Substantial protection against these effects was afforded by a broad-spectrum sunscreen.
mesh_terms: D000818:Animals; D003238:Connective Tissue / Q000473:pathology / Q000528:radiation effects*; D005260:Female; D006025:Glycosaminoglycans / Q000032:analysis; D051379:Mice; D008812:Mice, Hairless; D012867:Skin / Q000528:radiation effects*; D013473:Sunscreening Agents / Q000494:pharmacology; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D006025:Glycosaminoglycans; D013473:Sunscreening Agents