There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
In all living organisms, one of the most indispensable biological functions is the
circadian clock (suprachiasmatic nuclei; SCN), which acts like a multifunction timer
to regulate homeostatic systems such as sleep and activity, hormone levels, appetite,
and other bodily functions with 24h cycles. Circadian rhythms regulate diverse physiologic
processes, including homeostatic functions of steroid hormones and their receptors.
Perturbations of these rhythms are associated with pathogenic conditions such as depression,
diabetes and cancer. Clock genes are identified as the genes that ultimately control
a vast array of circadian rhythms in physiology and behavior. Clock gene regulates
several diseases such as cancer, metabolic syndrome and sleep etc. CLOCK mutation
affects the expression of rhythmic genes in wild-type (WT) tissue, but also affects
that of non-rhythmic genes. On the other hand, the change of the drug pharmacodynamic
and pharmacokinetic (PK/PD) parameters are influenced by not only inter-individual
variability but also intra-individual variabilities of medications. Identification
of a rhythmic marker for selecting dosing time will lead to improved progress and
diffusion of chronopharmacotherapy. The mechanisms underlying chronopharmacological
findings should be clarified from viewpoint of clock genes. On the other hand, several
drugs have an effect on molecular clock. Thus, the knowledge of intra- and inter-individual
variability of molecular clock should be applied for the clinical practice. Therefore,
we introduce the regulatory system of biological rhythm from viewpoints of clock genes
and the possibility of pharmacotherapy based on the intra- and inter-individual variability
of clock genes.
2010 Elsevier B.V. All rights reserved.