Physiological significance of a peripheral tissue circadian clock

Mammals have circadian clocks in peripheral tissues, but there is no direct evidence of their physiological importance. Unlike the suprachiasmatic nucleus clock that is set by light and drives rest-activity and fasting-feeding cycles, peripheral clocks are set by daily feeding, suggesting that at least some contribute metabolic regulation. The liver plays a well known role in glucose homeostasis, and we report here that mice with a liver-specific deletion of Bmal1, an essential clock component, exhibited hypoglycemia restricted to the fasting phase of the daily feeding cycle, exaggerated glucose clearance, and loss of rhythmic expression of hepatic glucose regulatory genes. We conclude that the liver clock is…

• UO
  University of Wisconsin-Madison
• LS
  Life Sciences Research Foundation
• UD
  Université de Genève
• UD
  Université de Lausanne
• NI
  National Institutes of Health