Light-induced phase-shifting of the peripheral circadian oscillator in the hearts of food-deprived mice.
In the present study, we investigated the effect of fasting on photoentrainment of the peripheral circadian oscillator in the mammalian heart. Northern blotting showed that a single light pulse applied at an appropriate time in constant darkness, caused obvious phase-shifting in the circadian expression rhythm of the mammalian clock gene Period2 (mPer2) even in the hearts of food-deprived mice. Fasting did not significantly affect either the phase or the light-induced phase-shifts of the mPer2 rhythm. Although several studies of temporal feeding restriction have indicated that feeding is the dominant timing cue for mammalian peripheral oscillators, our findings suggest that feeding is not essential for mammals to induce phase resetting of the circadian oscillator in the heart.
Sakamoto
Katsuhiko
K
Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310-1495, USA.
Kadota
Koji
K
Oishi
Katsutaka
K
D000818:Animals; D001683:Biological Clocks / Q000235:genetics* / Q000502:physiology*; D015152:Blotting, Northern; D018797:Cell Cycle Proteins; D002940:Circadian Rhythm / Q000235:genetics* / Q000502:physiology*; D005215:Fasting / Q000502:physiology*; D005508:Food Deprivation / Q000502:physiology*; D005786:Gene Expression Regulation; D006321:Heart / Q000502:physiology*; D008027:Light; D051379:Mice; D008807:Mice, Inbred BALB C; D009687:Nuclear Proteins / Q000235:genetics; D056950:Period Circadian Proteins; D010775:Photic Stimulation; D012333:RNA, Messenger / Q000378:metabolism; D014157:Transcription Factors
D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D014157:Transcription Factors