Effect of deuterium on the circadian period and metabolism in wild-type and tau mutant Syrian hamsters.
Homozygous tau mutant Syrian hamsters (tau-/-) have a free-running circadian period (tau) around 20 h and a proportionally higher metabolic rate compared with wild-type hamsters (tau+/+) with a period of circa 24 h. In this study, we applied deuterium oxide (D(2)O) to hamsters to test whether deuteration affects the circadian period of locomotor activity and metabolic rate in both genotypes. Running wheel activity and the metabolic rate were measured in constant illumination before, during, and after administration of 25% deuterium in drinking water. Wild-type hamsters lengthened their circadian period by 1.19 h (SD=0.29 h) due to D(2)O application and tau-/- hamsters by 1.20 h (SD=0.39 h). Deuteration changed neither the amount of activity nor the duration of activity phase (alpha) in either genotype. The mass specific average metabolic rate (AMR, the oxygen consumption over 24 h) and the mass specific resting metabolic rate (RMR) did not differ during deuteration compared with non-deuteration conditions for either genotype. Both with and without D(2)O, tau-/- hamsters had higher metabolic rates than tau+/+ hamsters. There was no correlation between changes in the circadian period of locomotor activity and metabolic rates caused by D(2)O.
Oklejewicz
M
M
Zoological Laboratory, University of Groningen, P.O. Box 14, 9750 AA, Haren, Netherlands. oklejewi@biol.rug.nl
Hut
R A
RA
Daan
S
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D000818:Animals; D001481:Basal Metabolism / Q000187:drug effects*; D002940:Circadian Rhythm / Q000187:drug effects*; D006224:Cricetinae; D003903:Deuterium / Q000494:pharmacology*; D005838:Genotype; D008297:Male; D008647:Mesocricetus; D009043:Motor Activity / Q000235:genetics / Q000502:physiology; D009154:Mutation / Q000235:genetics*; D016875:tau Proteins / Q000235:genetics*
D016875:tau Proteins; D003903:Deuterium