Shift in Food Intake and Changes in Metabolic Regulation and Gene Expression during Simulated Night-Shift Work: A Rat Model.
Night-shift work is linked to a shift in food intake toward the normal sleeping period, and to metabolic disturbance. We applied a rat model of night-shift work to assess the immediate effects of such a shift in food intake on metabolism. Male Wistar rats were subjected to 8 h of forced activity during their rest (ZT2-10) or active (ZT14-22) phase. Food intake, body weight, and body temperature were monitored across four work days and eight recovery days. Food intake gradually shifted toward rest-work hours, stabilizing on work day three. A subgroup of animals was euthanized after the third work session for analysis of metabolic gene expression in the liver by real-time polymerase chain reaction (PCR). Results show that work in the rest phase shifted food intake to rest-work hours. Moreover, liver genes related to energy storage and insulin metabolism were upregulated, and genes related to energy breakdown were downregulated compared to non-working time-matched controls. Both working groups lost weight during the protocol and regained weight during recovery, but animals that worked in the rest phase did not fully recover, even after eight days of recovery. In conclusion, three to four days of work in the rest phase is sufficient to induce disruption of several metabolic parameters, which requires more than eight days for full recovery.
Department of Biological and Medical Psychology, University of Bergen, Bergen 5009, Norway. andrea.marti@uib.no.
Andrea Rørvik
AR
Marti
Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 CC Groningen, The Netherlands. p.meerlo@rug.nl.
Peter
P
Meerlo
Department of Biological and Medical Psychology, University of Bergen, Bergen 5009, Norway. janne.gronli@uib.no.|College of Medical Sciences, Washington State University, Spokane, WA 99210, USA. janne.gronli@uib.no.|Sleep and Performance Research Center, Washington State University, Spokane, WA 99210, USA. janne.gronli@uib.no.
Janne
J
Grønli
Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 CC Groningen, The Netherlands. sjoerdvanhasselt@live.nl.
Sjoerd Johan
SJ
van Hasselt
Department of Biological and Medical Psychology, University of Bergen, Bergen 5009, Norway. jelena.mrdalj@uib.no.|Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen 5021, Norway. jelena.mrdalj@uib.no.
Jelena
J
Mrdalj
Department of Psychosocial Science, University of Bergen, Bergen 5015, Norway. staale.pallesen@uib.no.|Section of Psychiatry, Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of Bergen, Bergen 5021, Norway. staale.pallesen@uib.no.
Ståle
S
Pallesen
Department of Biological and Medical Psychology, University of Bergen, Bergen 5009, Norway. torhildp@hotmail.com.
Torhild Thue
TT
Pedersen
Section of Psychiatry, Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of Bergen, Bergen 5021, Norway. tone.elise.gjotterud@helse-fonna.no.|Division of Mental Health Care, Valen Hospital, Fonna Local Health Authority, Valen 5451, Norway. tone.elise.gjotterud@helse-fonna.no.
Tone Elise Gjøtterud
TE
Henriksen
Dr. Einar Martens Research Group for Biological Psychiatry, Center for Medical Genetics and Molecular Medicine, Haukeland Univeristy Hospital, 5021 Bergen, Norway. silje.skrede@uib.no.
Silje
S
Skrede
D000818:Animals; D001831:Body Temperature; D001835:Body Weight; D002940:Circadian Rhythm / Q000502:physiology*; D004435:Eating / Q000502:physiology*; D015870:Gene Expression / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D008099:Liver / Q000378:metabolism; D008297:Male; D008660:Metabolism / Q000502:physiology*; D023421:Models, Animal; D051381:Rats; D017208:Rats, Wistar; D014940:Work Schedule Tolerance / Q000502:physiology*
animal model; body temperature; body weight; circadian rhythmicity; food intake; gene expression; metabolism; night work; shift work