title: Infrared radiation suppresses ultraviolet B-induced sunburn-cell formation.
abstract: Sunburn cell (SC) formation, a quantifiable measure of epidermal cell injury induced in mouse ear skin by ultraviolet-B (UVB) radiation (290-320 nm), was significantly decreased by pre-exposure to infrared radiation (IR), which elevated the surface temperature of ear lobes to 37-42 degrees C. An autoradiographic study demonstrated that the basal cell labelling indices were significantly reduced in a surface temperature-dependent manner by pre-exposure to IR. Taken together with our previous findings that SC formation depends upon the ratio of cycling to non-cycling cells, the present findings suggest that IR retards the cell cycle and, as a result, decreases SC formation. SC counts were not altered by post-UVB exposure to IR. The effect of IR or the IR-induced increase in surface temperature should be considered when studying cutaneous damage by UVB and sunlight.
authors.affiliation: Department of Dermatology, Kyoto University Faculty of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Danno
authors.forename: T
authors.initials: T
authors.lastname: Horio
authors.forename: S
authors.initials: S
authors.lastname: Imamura
mesh_terms: D000818:Animals; D001345:Autoradiography; D002452:Cell Count / Q000528:radiation effects; D005260:Female; D007259:Infrared Rays; D051379:Mice; D008813:Mice, Inbred ICR; D013471:Sunburn / Q000473:pathology / Q000517:prevention & control*; D014466:Ultraviolet Rays