title: Histopathological Analysis of UVB and IR Interaction in Rat Skin.
abstract: To determine the chronic skin effects caused by the interaction of infrared and ultraviolet B radiations, male Rattus norvegicus (Wistar) (2 months old) were exposed for 15 days to infrared radiation (600-1500 nm, with a peak at 1000 nm, n = 12) for 30 min (1080 J cm(-2) ) (IRo); to ultraviolet B radiation (peak emission at 313 nm, n = 9) for 90 min (55.08 J cm(-2) ) (UVB); to infrared radiation followed after 90 min by ultraviolet B (n = 6) (IRUVB) and to ultraviolet B followed after 90 min by infrared radiation (n = 9) (UVBIR). Skin samples were collected and histopathological analysis showed the presence of acanthosis, parakeratotic and orthokeratotic hyperkeratosis, intraepidermal pustules, keratin pearls, detachment of epidermis, collagen necrosis, inflammatory infiltrate, vasodilation, basal cell vacuolization and superficial dermis degeneration both in UVB and UVBIR treatments. IRUVB animals showed the same characteristics as above except for parakeratotic hyperkeratosis, keratin pearls and superficial dermis degeneration. To conclude, infrared radiation exposure after ultraviolet B irradiation increases skin damage without protecting the tissue, while infrared radiation exposure before ultraviolet B irradiation showed a protective effect against ultraviolet skin damage.
authors: Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande, Rio Grande, Brazil.
authors: Vinícius C
authors: http://orcid.org/0000-0002-8354-4972
authors: VC
authors: Gonzalez
authors: Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, Brazil.
authors: Ana C M
authors: AC
authors: Beheregaray
authors: Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, Brazil.
authors: Bárbara M
authors: BM
authors: Peres
authors: Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, Brazil.
authors: Eliza S V
authors: ES
authors: Sallis
authors: Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, Brazil.
authors: Antônio S
authors: AS
authors: Varela Junior
authors: Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande, Rio Grande, Brazil.
authors: Gilma S
authors: GS
authors: Trindade
mesh_terms: D000818:Animals; D007259:Infrared Rays; D051381:Rats; D012867:Skin / Q000528:radiation effects*; D014466:Ultraviolet Rays