title: Circadian expressions of cardiac ion channel genes in mouse might be associated with the central clock in the SCN but not the peripheral clock in the heart.
abstract: Significant circadian variations exist in the frequency of cardiac arrhythmia, but few studies have examined the relation between cardiac ion channels genes and biological clocks. We investigated this relation using suprachiasmatic nuclei lesion (SCNX) and pharmacological autonomic nervous system block (ANSB) mice. Significant 24-h variations were observed in the expression of clock genes Per2, Bmal1, and Dbp and ion channel genes KCNA5, KCND2, KCHIP2, and KCNK3 in the control mice hearts. In the SCNX mice, all genes examined lost circadian rhythm. In the ANSB mice, the expressions of the three clock genes were dampened significantly but still had circadian rhythm, whereas the four ion channel gene expressions lost rhythm. Heart rate also lost circadian rhythm in both the SCNX and ANSB mice. These results suggest that some ion channel gene expressions might be regulated by the central clock in the SCN through the ANS but not the peripheral clock in the heart.
authors: Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
authors: Maoqing
authors: M
authors: Tong
authors: Eiichi
authors: E
authors: Watanabe
authors: Naoki
authors: N
authors: Yamamoto
authors: Misao
authors: M
authors: Nagahata-Ishiguro
authors: Koji
authors: K
authors: Maemura
authors: Norihiko
authors: N
authors: Takeda
authors: Ryozo
authors: R
authors: Nagai
authors: Yukio
authors: Y
authors: Ozaki
keywords: arrhythmia; autonomic nervous system; circadian rhythm; suprachiasmatic nuclei