Regulation of Na-pump gene expression in cardiovascular system

Na，K-ATP酶，也称为肌膜Na^+泵，是哺乳动物细胞中普遍存在的跨膜蛋白，其维持跨质膜的电化学Na^+和K^+梯度，并影响各种细胞的兴奋性、收缩性和细胞体积调节。Na，K-ATP酶蛋白由两个亚基组成：一个较大的催化α亚基和一个较小的功能未知的糖基化β亚基。至少有三种α亚基亚型，α 1，α 2和α 3，已在大鼠和人类的特点。本研究旨在探讨钠离子和不同激素对心血管系统Na，K-ATP酶α 1和β 1 mRNA表达的影响。用北方印迹法分析Na，K-ATP酶mRNA的表达，用酶联免疫吸附试验（ELISA）分析Na^+泵蛋白的含量。我们已经发现，钠离子，甲状腺激素和血管紧张素II刺激大鼠血管平滑肌细胞，系膜细胞和心肌细胞的Na，K-ATP酶α 1和β 1亚型mRNA和蛋白质的表达，并调节这些细胞的收缩性，兴奋性和容量调节。

Na, K-ATPase, also called the sarcolemmal Na^+-pump, is a ubiquitous transmembrane protein of mammalian cells that maintains electrochemical Na^+ and K^+ gradients across the plasma membrane and affects excitability, contractility, and cell volume regulation of various kinds of cells. The Na, K-ATPase protein comprises two subunits : a large catalytic alpha-subunit and a smaller glycosylated beta-subunit of unknown function. At least three alpha-subunit isoforms, alpha1, alpha2, and alpha3, have been characterized in rats and humans. Two beta-subunit isoforms, beta1 and beta2, have been identified in rats.In the present research project, we investigated the effects of sodium ion and various hormones on Na, K-ATPase alpha1 and beta1 mRNA expression in the cardiovascular system. Na, K-ATPase mRNA expression was analyzed by Northern blotting and Na^+-pump protein content was analyzed by enzyme-linked immunosorbent assay (ELISA). We have revealed that sodium ion, thyroid hormone, and angiotensin II stimulate Na, K-ATPase alpha1-and beta1-isoform mRNA and protein expression in rat vascular smooth muscle cells, mesangial cells, and cardiac myocytes and regulate contractility, excitability, and volume regulation of these cells.