Department of Environmental and Biological Sciences, University of Eastern Finland, Finland.
Department of Environmental and Biological Sciences, University of Eastern Finland, Finland.
Prog Biophys Mol Biol. 2018 Oct;138:59-68. doi: 10.1016/j.pbiomolbio.2018.04.002. Epub 2018 Apr 12.
Na channel α-subunit composition of the zebrafish heart and electrophysiological properties of Na current (I) of zebrafish ventricular myocytes were examined. Eight Na channel α-subunits were expressed in both atrium and ventricle of the zebrafish heart. Na1.5Lb, an orthologue to the human Na1.5, was clearly the predominant isoform in both chambers representing 65.2 ± 4.1% and 83.1 ± 2.1% of all Na channel transcripts in atrium and ventricle, respectively. Na1.4b, an orthologue to human Na1.4, formed 34.1 ± 4.1 and 16.2 ± 2.0% of the Na channel transcripts in atrium and ventricle, respectively. The density of I and the rate of action potential upstroke in zebrafish ventricular myocytes at 28 °C were similar to those of human ventricles at the comparable temperature. Na channel isoforms and the main electrophysiological characteristics of the I are largely similar in zebrafish and human hearts indicating evolutionary conservation of Na channel composition and function. The zebrafish I differs from the human cardiac I in terms of higher tetrodotoxin sensitivity (IC-value = 5.3 ± 0.1 nM) and slower inactivation kinetics. The zebrafish I was inhibited with tricaine (MS-222) with an IC-value of 1.2 ± 0.18 mM (336 mg l), suggesting some care in the use of MS-222 as an anesthetic.
研究了斑马鱼心脏的钠通道α亚基组成和钠电流（I）的电生理特性。 8 种钠通道α亚基在斑马鱼心脏的心房和心室中均有表达。 Na1.5Lb，与人源 Na1.5 的同源物，在两个腔室中均明显是主要亚型，分别占心房和心室中所有钠通道转录本的 65.2±4.1％和 83.1±2.1％。 Na1.4b，与人源 Na1.4 的同源物，在心房和心室中分别构成钠通道转录本的 34.1±4.1％和 16.2±2.0％。 28°C 时斑马鱼心室肌细胞中 I 的密度和动作电位上升速率与可比温度下的人类心室相似。 钠通道亚型和 I 的主要电生理特性在斑马鱼和人类心脏中基本相似，表明钠通道组成和功能在进化上是保守的。 与人类心脏相比，斑马鱼 I 的特点是更高的河豚毒素敏感性（IC 值=5.3±0.1 nM）和较慢的失活动力学。 斑马鱼 I 被三卡因（MS-222）抑制，IC 值为 1.2±0.18 mM（336 mg l），表明在使用 MS-222 作为麻醉剂时需要小心。
