Masumiya Haruko, Yamamoto Hideyuki, Hemberger Myriam, Tanaka Hikaru, Shigenobu Koki, Chen S R Wayne, Furukawa Tetsushi
Department of Bio-informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, Japan.
FEBS Lett. 2003 Oct 9;553(1-2):141-4. doi: 10.1016/s0014-5793(03)00999-2.
Ca(2+) released from intracellular Ca(2+) stores is shown to be involved in pacemaker activity in the sino-atrial (SA)-node. However, little is known about the molecular identity of the Ca(2+) release channel/ryanodine receptor (RYR) involved in pacemaker activity. We examined the mRNA distribution of three different RYR isoforms (RYR1, RYR2, and RYR3) in the mouse SA-node. RNase protection assay and in situ hybridization revealed that RYR2 mRNA expresses widely in the heart including the SA-node, while RYR3 mRNA expression is limited to the SA-node and to the right atrium. Thus, not only RYR2 but also RYR3 may participate in pacemaker activity.
研究表明，从细胞内钙库释放的Ca(2+)参与了窦房结的起搏活动。然而，对于参与起搏活动的Ca(2+)释放通道/雷诺丁受体（RYR）的分子特性却知之甚少。我们检测了三种不同RYR亚型（RYR1、RYR2和RYR3）在小鼠窦房结中的mRNA分布。核糖核酸酶保护分析和原位杂交显示，RYR2 mRNA在包括窦房结在内的心脏中广泛表达，而RYR3 mRNA的表达仅限于窦房结和右心房。因此，不仅RYR2，而且RYR3都可能参与起搏活动。
