Induction and Persistence of Pyrimidine Dimers in the Epidermal DMA of Two Strains of Hairless Mice1
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چکیده
cent sun lamp (280 to 400 nm), respectively. Enzymatic photoreactivation with yeast photoreactivating enzyme showed that -80% of the endonuclease-sensitive sites were cyclobutyl pyrimidine dimers. In both strains of mice the pyrimidine dimers remained in high-molecular-weight DNA for 24 hr after irradiation. These data show that mouse epi thelial cells in vivo have little or no capacity for the excision repair of pyrimidine dimers.
منابع مشابه
Induction and persistence of pyrimidine dimers in the epidermal DNA of two strains of hairless mice.
The ultraviolet-light induction of DNA damage has been measured in the epidermis of hairless mice with the use of damage-specific endonucleases from Micrococcus luteus. The rates of induction of endonuclease-sensitive sites in HRS/J/Anl and Skh:hairless-1 mice were 6.1 +/- 0.5 X 10(-11) and 6.5 +/- 0.8 X 10(-11)/dalton/J/sq m from a FS40 fluorescent sun lamp (280 to 400 nm), respectively. Enzym...
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Chronic exposure to sunlight causes skin cancer in humans, yet little is known about how habitual exposure to low doses of ultraviolet B radiation (UVB) affects DNA damage in the skin. We treated Skh-1 hairless mice with daily doses of suberythemal UVB for 40 days and analyzed the amount and distribution of DNA photodamage using RIAs and immunofluorescence micrography. We found that DNA damage ...
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UV exposure has been linked to skin cancer in humans by epidemi ology and the rare genetic disease xeroderma pigmentosum. However, UV produces multiple photoproducts in DNA, and their relative contri bution is uncertain. An enzyme which specifically repairs cyclobutane pyrimidine dimers in DNA, T4 endonuclease V, was encapsulated in liposomes for topical delivery into mouse and human skin. In b...
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BACKGROUND We studied the mechanism by which fermented milk ameliorates UV-B-induced skin damage and determined the active components in milk fermented with lactic acid bacteria by evaluating erythema formation, dryness, epidermal proliferation, DNA damage and cytokine mRNA levels in hairless mice exposed to acute UV-B irradiation. METHODS Nine week-old hairless mice were given fermented milk...
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