Effects of atrial natriuretic peptide on the sarcolemmal Na-K pump in rabbit myocytes

钠泵将钠离子从细胞内部穿过细胞膜输送到细胞外部。这使得内部的钠浓度比外部低十倍以上。这种跨膜浓度梯度对于正常细胞功能是必不可少的。众所周知，钠泵受到多种激素的调节。在一项初步研究中，我们已经证明，心脏分泌的一种激素，心房利钠肽，刺激单个心脏细胞的钠泵。这在以前没有报道过。本研究将探讨心房钠尿肽介导钠泵刺激的细胞机制。从心力衰竭的角度来看，研究心房利钠肽对心脏细胞中钠调节的影响尤为重要，心力衰竭是一种以心脏无法泵送足够量血液为特征的疾病。虽然心力衰竭的潜在原因差异很大，但无论病因如何，几种激素系统的激活是一个共同特征。在临床实践中已经很好地建立了通过药物干扰激素激活来改善症状以及存活率。最近已经开发出可以增加心房利钠肽水平的药物。由于钠水平升高可能导致心力衰竭中重要的心脏细胞异常，因此心房利钠肽对通过泵从细胞输出钠的作用可能对这种严重和常见疾病的治疗具有重要意义。

The sodium pump transports sodium ions across cell membranes from the inside of cells to the outside. This maintains the concentration of sodium more than ten-fold lower on the inside than the outside. This transmembrane concentration gradient is essential for normal cell function. It is well established that the sodium pump is regulated by a variety of hormones. In a pilot study we have demonstrated that a hormone secreted by the heart, atrial natriuretic peptide, stimulates the sodium pump in single heart cells. This has not been reported previously. This study will examine the cellular mechanisms that mediate the stimulation of the sodium pump by atrial natriuretic peptide. A study on the effect of atrial natriuretic peptide on the regulation of sodium in heart cells is particularly important from the perspective of heart failure, a condition characterised by an inability of the heart to pump a sufficient amount of blood. While the underlying causes of heart failure vary widely activation of several hormone systems is a common feature regardless of the aetiology. It has already been well established in clinical practice that interfering with hormone activation by drugs improves symptoms as well as survival. Drugs have recently been developed that can increase levels of atrial natriuretic peptide. Since raised levels of sodium may contribute to important heart cell abnormalities in heart failure the effect of atrial natriuretic peptide on sodium export from the cells by the pump may have important implications for treatment of this serious and common condition.