Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Discovery that intermittent over-exposure to UVB radiation (not UVA1 radiation) is effective in stimulating melanocyte proliferation

The major results ('deliverables') of our activity in the MAUVE project concerning proliferation of pigment cells (melanocytes) in response to UV exposure:

- 1 - "Intermittent overexposure to UVB radiation is most effective in stimulating melanocyte proliferation; fractionated sub-sunburn doses of UV are ineffective".(to be avoided because of possible simulation of melanocytic lesions; see next point).

- 2 - "Long wavelength UVA1 radiation did not induce any proliferative response in our pigmented mice".

- 3 - "Mice with a defect in repair of UVB-induced DNA damage (pyrimidine dimers) were found to be extremely sensitive to induction of melancyte proliferation".

Notes:
Sub - 1 -: this could explain the increase melanoma risk associated with intermittent sunburn exposures.
Sub - 2 -: This shows that UVA1 has little indirect or direct effects on melanocytes capable of producing dark pigment (eumelanin).
Sub - 3 - this stimulation is causally related to DNA damage as it is enhanced in DNA repair deficient XPA mice.

Informazioni correlate

Reported by

Leiden University Medical Centre
Postal Zone S2P
2300 RC Leiden
Netherlands