Time and dose-related ultraviolet B damage in viable pig skin explants held in a newly developed organ culture system.
For facilitating photochemical and toxicological studies an ex vivo skin model was developed in our laboratory using skin from domestic pigs. The model comprised the use of a complete skin piece, including the dermis and stratum corneum, of bigger areas to make future topical applications easier. Fully differentiated skin explants (5 x 50 mm, thickness 5 mm) were irradiated with ultraviolet B (UVB; 1-10 kJ/m2; 6 W/m2). Directly thereafter they were brought in culture (Dulbeccos modified Eagles medium containing hydrocortisone; air/liquid interface) for a maximum of 144 h. In nonirradiated skin explants, signs of tissue degeneration were observed after 48 h in culture (hematoxylin and eosin, light microscope). However, keratinocytes, isolated enzymatically (thermolysin and trypsin) at different time intervals in culture from nonirradiated skin explants showed negligible loss in viability (trypan blue exclusion) and increased apoptosis (terminal deoxynucleotidyl transferase-mediated deoxy uridine triphosphatase nick end labeling assay) for up to 72 h. Explants irradiated with a single dose of UVB showed a clear and reproducible dose- and time-dependent tissue degeneration, loss in keratinocyte viability and increase in apoptosis compared with nonirradiated explants at the same time interval. In conclusion, the presently designed ex vivo pig skin model can be a useful and cheap tool for future investigations of short-term UV-induced effects in combination with phototoxic and photoprotective compounds.
Rijnkels
J M
JM
Department of Pharmacochemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Gorleaus Laboratories, Leiden, The Netherlands. jmrijnkels@hotmail.com
Whiteley
L O
LO
Beijersbergen van Henegouwen
G M
GM
D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D046508:Culture Techniques / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D005260:Female; D015603:Keratinocytes / Q000166:cytology / Q000528:radiation effects; D012867:Skin / Q000166:cytology / Q000528:radiation effects*; D013552:Swine; D013997:Time Factors; D014466:Ultraviolet Rays / Q000009:adverse effects*