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Miniature swine model of phototoxicity testing.

Authors :
Leigh, Heinz
Forbes, Paul Donald
Lawson, Charles
Kim, Dae Young
White, David
Brown, Larry D.
Wehmeier, Dean R.
Liu, Jason
Bouchard, Guy F.
Source :
Photodermatology, Photoimmunology & Photomedicine. Feb2012, Vol. 28 Issue 1, p34-41. 8p. 5 Charts, 3 Graphs.
Publication Year :
2012

Abstract

Summary Background/Purpose This study determined the threshold doses for 'solar erythema' and for phototoxic responses to 8-methoxypsoralen (8- MOP) in white skin Hanford and grey skin Yucatan miniature swine. Methods For threshold erythema determinations, the UVR exposures included both UVA (315-400 nm) and UVB (290-315 nm) radiation by positioning one fluorescent 'sunlamp' among 10 ' PUVA' lamps. With this configuration the UVR exposures ranged from 0.5-2.8 times the 'instrumental MED' ( MEDi) for Hanford and from 1.0-5.6 times the MEDi for Yucatan. For phototoxicity determinations (i.e., with and without topically-applied graduated concentrations of 8- MOP), the UVB component was minimized by extinguishing the sunlamp, thus permitting higher UVA exposures. Results The Hanford had the lower UV erythema dose threshold (1.0-1.4 times the MEDi) and the erythema that developed was readily observable. The exposure doses for the phototoxicity test were 5 J/cm2 of UVA in 35 minutes or 10 J/cm2 in 70 minutes. The phototoxic (vascular) response to 8- MOP was observed in the two highest concentrations (0.01% and 0.1%) in Hanford pigs, in a dose-related manner. Microscopic evidence of a dose-related response was also observed as the concentration of 8- MOP increased. Conclusion This verified that the Hanford miniature swine is the preferable strain for phototoxic effects. In contrast, UVR exposure of the Yucatan pig skin produced tanning rather than erythema, confirming that the Yucatan is the more appropriate strain for studying the melanization response. Thus, Hanford and Yucatan miniature swine have cutaneous photobiological responses that reflect their respective strain differences. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
09054383
Volume :
28
Issue :
1
Database :
Academic Search Index
Journal :
Photodermatology, Photoimmunology & Photomedicine
Publication Type :
Academic Journal
Accession number :
69971740
Full Text :
https://doi.org/10.1111/j.1600-0781.2011.00633.x