title: Influence of near-ultraviolet radiation on reproductive and immunological development in juvenile male Siberian hamsters.
abstract: The aim of this study was to characterize the lenticular ultraviolet transmission of the Siberian hamster (Phodopus sungorus) and to probe the range of near-ultraviolet (UV-A, 315-400 nm) and visible wavelengths (400-760 nm) for modulating the photoperiodic regulation of its reproductive and immune systems. Ocular lenses from adult hamsters were found to transmit UV-A wavelengths at similar levels to visible wavelengths, with a short-wavelength cut-off of 300 nm. Five separate studies compared the responses of juvenile male hamsters to long photoperiods (16 h:8 h L:D), short photoperiods (10 h:14 h L:D) and short photoperiods interrupted by an equal photon pulse of monochromatic light of 320, 340, 360, 500 or 725 nm during the night. The results show that UV-A wavelengths at 320, 340 and 360 nm can regulate both reproductive and immune short-photoperiod responses as effectively as visible monochromatic light at 500 nm. In contrast, long-wavelength visible light at 725 nm did not block the short-photoperiod responses. These results suggest that both wavelengths in the visible spectrum, together with UV-A wavelengths, contribute to hamster photoperiodism in natural habitats.
authors.affiliation: Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA. george.brainard@mail.tju.edu
authors.forename: G C
authors.initials: GC
authors.lastname: Brainard
authors.forename: J P
authors.initials: JP
authors.lastname: Hanifin
authors.forename: F M
authors.initials: FM
authors.lastname: Barker
authors.forename: B
authors.initials: B
authors.lastname: Sanford
authors.forename: M H
authors.initials: MH
authors.lastname: Stetson
mesh_terms: D000818:Animals; D006224:Cricetinae; D003412:Cricetulus; D005837:Genitalia, Male / Q000254:growth & development; D008297:Male; D008647:Mesocricetus; D012098:Reproduction / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared