Decreased DNA repair activity in sunburn cells. A possible pathogenetic factor of the epidermal sunburn reaction.
The pathogenesis of the formation of sunburn cells is unknown. Based on autoradiographic methods the unscheduled DNA repair synthesis of UV-induced thymin dimers was investigated in vivo in sunburn cells and in irradiated but histologically normal stratum spinosum cells. The results show a significant lower number of sparsly labeled cells in the sunburn cell-population (13.2 +/- 2.5; mean) when compared to the population of normal stratum spinosum cells (57.8 +/- 7.5; mean). These data indicate that the population of those epidermal cells, which become manifest as sunburn cells 24 h after UV exposure exhibit a reduced DNA repair of UV induced thymine dimers immediately after UV irradiation. Nuclear factors thus seem to play at least some role in the origin of sunburn cells.
D004260:DNA Repair / Q000528:radiation effects*; D004817:Epidermis / Q000528:radiation effects / Q000648:ultrastructure; D006801:Humans; D012867:Skin / Q000473:pathology / Q000528:radiation effects*; D013471:Sunburn / Q000473:pathology*; D014466:Ultraviolet Rays / Q000009:adverse effects*