体温可以重置生物钟

Numerous processes in our body fluctuate（波动，动摇） in a regular pattern during the day. These circadian (or daily) variations can be driven by local oscillators（振荡器） present within our cells or by systemic signals controlled by the master pacemaker, located in the brain. Ueli Schibler, profes- sor at the University of Geneva (UNIGE), Switzerland, unveils a mo- lecular mechanism¹ by which body temperature rhythms influence the expression of 'clock genes²' and synchronize³ local oscillators. This study, made in collaboration⁴ with a team at the Ecole polytechnique fédérale of Lausanne (EPFL), also demonstrates how the production of DBP, a protein involved in detoxification and drug metabolism⁵（新陈代谢）, is modulated⁶ by daily variations of temperature. This research has been published in Science.   Many of our physiological⁷ functions, such as heart beat frequency, hormone⁸ secretion⁹ or body temperature, are regulated by internal clocks. Most of our body's cells possess one of them, formed by a group of 'clock genes' displaying a cyclic activity that peaks every twenty-four hours. These local oscillators are synchronized¹⁰ by a central pacemaker, located in the brain which adapts to geophysical time by light-dark cycles.   The master clock also controls coordination¹¹ signals that are sent to subsidiary oscillators. 'Body temperature variations constitute one of these daily resetting¹² cues, but we did not know how it functioned', explains Ueli Schibler, professor at the Department of Molecular¹³ Biology of the UNIGE. To address this issue, the researcher's team has developed a system allowing to expose cells to simulated body temperatures cycles.