Sunburn Effect on Keratinosomes

Ultrastructure of the epidermal barrier after irritation

“…A growing body of data indicates that the occurring repair responses of the epidermis, which seem regulated by the interplay of Ca 11 and K 1 ions (Lee et al, 1994), involve first the immediate secretion of preformed LB lipids by the outer stratum granulosum cells (Menon et al, 1992(Menon et al, , 1994aWilgram et al, 1970) and later the increased formation of new LB. This could be accompanied by the increase in epidermal lipid synthesis, the activation of its regulatory enzymes (Grubauer et al, 1989), and finally the stimulation of DNA synthesis (Proksch et al, 1991a) leading to epidermal hyperplasia.…”

Perinuclear Halo Formation as an Indication of Phototoxic Effects

“…lc). The perinuclear halo has been observed in electron microscope studies [6] after exposure to UVB. In addition, the keratinocytes showed a decrease in keratinosomes, clumping of tonofilaments, cytoplasmic vacuolization and nuclear degeneration.…”

“…This region constitutes about 0.1-0.2% of the sun's energy that reaches the earth and at least 20% of this energy reaches the viable cells of the epidermis in persons of Caucasian origin [1], Light of this wavelength produces the delayed erythema response that we call 'sunburn' and is also responsible for skin cancer induction. The presence of perinuclear vacuoles or a perinuclear halo is one of the alterations described in UVB-induced dyskeratinosis [6].…”