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Author (up) Bullough, J.D.; Rea, M.S.; Figueiro, M.G.
Title Of mice and women: light as a circadian stimulus in breast cancer research Type Journal Article
Year 2006 Publication Cancer Causes & Control : CCC Abbreviated Journal Cancer Causes Control
Volume 17 Issue 4 Pages 375-383
Keywords Human Health; Animals; Breast Neoplasms/*physiopathology; *Circadian Rhythm; *Disease Models, Animal; Female; Humans; *Light; Light Signal Transduction; Mammary Neoplasms, Animal/*physiopathology; Melatonin/metabolism; Mice; Muridae/metabolism
Abstract OBJECTIVE: Nocturnal rodents are frequently used as models in human breast cancer research, but these species have very different visual and circadian systems and, therefore, very different responses to optical radiation or, informally, light. Because of the impact of light on the circadian system and because recent evidence suggests that cancer risk might be related to circadian disruption, it is becoming increasingly clear that optical radiation must be properly characterized for both nocturnal rodents and diurnal humans to make significant progress in unraveling links between circadian disruption and breast cancer. In this paper, we propose a quantitative framework for comparing radiometric and photometric quantities in human and rodent studies. METHODS: We reviewed published research on light as a circadian stimulus for humans and rodents. Both suppression of nocturnal melatonin and phase shifting were examined as outcome measures for the circadian system. RESULTS: The data were used to develop quantitative comparisons regarding the absolute and spectral sensitivity for the circadian systems of humans and nocturnal rodents. CONCLUSIONS: Two models of circadian phototransduction, for mouse and humans, have been published providing spectral sensitivities for these two species. Despite some methodological variations among the studies reviewed, the circadian systems of nocturnal rodents are approximately 10,000 times more sensitive to optical radiation than that of humans. Circadian effectiveness of different sources for both humans and nocturnal rodents are offered together with a scale relating their absolute sensitivities. Instruments calibrated in terms of conventional photometric units (e.g., lux) will not accurately characterize the circadian stimulus for either humans or rodents.
Address Lighting Research Center, Rensselaer Polytechnic Institute, 21 Union Street, Troy, NY 12180, USA. bulloj@rpi.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0957-5243 ISBN Medium
Area Expedition Conference
Notes PMID:16596289 Approved no
Call Number LoNNe @ kagoburian @ Serial 726
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Author (up) Oike, H.; Sakurai, M.; Ippoushi, K.; Kobori, M.
Title Time-fixed feeding prevents obesity induced by chronic advances of light/dark cycles in mouse models of jet-lag/shift work Type Journal Article
Year 2015 Publication Biochemical and Biophysical Research Communications Abbreviated Journal Biochem Biophys Res Commun
Volume 465 Issue 3 Pages 556-561
Keywords Animals; *Circadian Clocks; *Disease Models, Animal; *Feeding Behavior; Jet Lag Syndrome/*physiopathology; Male; Mice; Mice, Inbred C57BL; Obesity/etiology/*physiopathology/*prevention & control; Photoperiod; Circadian rhythm; Clock genes; Jet lag; Metabolic disorders; Obesity; Shift work
Abstract Recent findings have uncovered intimate relationships between circadian clocks and energy metabolism. Epidemiological studies have shown that the frequency of obesity and metabolic disorders increases among shift-workers. Here we found that a chronic shift in light/dark (LD) cycles comprising an advance of six hours twice weekly, induced obesity in mice. Under such conditions that imitate jet lag/shift work, body weight and glucose intolerance increased, more fat accumulated in white adipose tissues and the expression profiles of metabolic genes changed in the liver compared with normal LD conditions. Mice fed at a fixed 12 h under the LD shift notably did not develop symptoms of obesity despite isocaloric intake. These results suggest that jet lag/shift work induces obesity as a result of fluctuating feeding times and it can be prevented by fixing meal times. This rodent model of obesity might serve as a useful tool for understanding why shift work induces metabolic disorders.
Address Food Function Division, National Food Research Institute, National Agriculture and Food Research Organization (NARO), 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan; oike(at)affrc.go.jp
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0006-291X ISBN Medium
Area Expedition Conference
Notes PMID:26297949 Approved no
Call Number IDA @ john @ Serial 1318
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