In the dorsal epidermis of both C57BL/10J and C3WHe mice, the number of melanocytes positive to the dopa reaction increased from birth to 3 or 4 days of age, and then gradually decreased and disappeared by 30 days of age. However, the number of melanoblasts plus melanocytes positive to the combined
The epidermal melanocyte population in the skin of ultraviolet-irradiated crested newt
β Scribed by Losa, Massimo ;Zavanella, Teresa ;Milani, Silvano
- Publisher
- John Wiley and Sons
- Year
- 1982
- Tongue
- English
- Weight
- 707 KB
- Volume
- 219
- Category
- Article
- ISSN
- 0022-104X
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β¦ Synopsis
Abstract
The response of the epidermal melanocyte population to repeated ultraviolet (UV) exposure (wavelength spectrum 275β350 nm) has been investigated in the crested newt, Triturus cristatus carnifex. The effects of different doses of UV light were studied. The animals were killed 7 months after the first UV exposure. Only a slight decrease in the number of pigment cells was found after 85 sequential irradiations with a total dose of 1.3 Γ 10^5^ J/m^2^, whereas striking decreases were observed when the same total dose was fractionated into 14 exposures or when a double dose was given in 57 exposures. The relationship between the square roots of the epidermal melanocyte densities and single doses appeared to be roughly linear, at least over the range of doses administered. The main factor in melanocyte damage seemed to be the single dose of irradiation rather than the cumulative dose administered. Decreased melanin content of the keratinocytes was observed in most irradiated animals.
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