抄録
In mammals, behavioral and physiologic process display 24-hour rhythmus that are regulated by a circadian system. Circadian oscillators exist not only in the suprachiasmatic nucleus in the brain, which harbors the central pacemaker, but also in most peripheral tissues. Because blood pressure show diurnal variations and abnormal patterns of circadian blood pressure variation carry a high risk of cardiovascular complications, it is important to identify the underling molecular mechanisms of diurnal change in blood pressure. To this end, we have been currently undergoing the several approaches; 1) to investigate which clock system, central or peripheral, involves the diurnal regulation of blood pressure by dissociating the central and peripheral clocks using the restricted daytime feeding (RF) method, 2) to identify the tissue specific clock output genes in the peripheral tissues by suppressive subtractive hybridization method, and examine the expression changes in the presence or absence of hypertension, 3) to establish easy and rapid assay methods to assess the individual circadian time in human. Our observations should also be beneficial for chronotherapeutics, a circadian time-specified treatment since pharmacokinetic parameters including drug absorption, transport, metabolism, and elimination, are known to display significant daily variations. The establishment of the assay method for human circadian system should be useful to introduce the chronotherapeutics into practical medicine, and hence to further evaluate the effectiveness for chronotherapeutics. [Jpn J Physiol 55 Suppl:S25 (2005)]
