Mechanisms of Na and Ca Transport Across the Plasma Membrane of Squid Giant Axons

Na/Ca交换是一种膜结合机制， 从细胞中排出净Ca。 Na/Ca的重要性 交换从其挤出大Ca负载的能力是明显的; 然而，该系统的另一个基本方面导致 从它的能力，在某些条件下，工作在“反向” 促进净钙增加和相应的增加 电离的钙的水平！的细胞。 相关的网页资讯 功能是生理和病理的，因为 细胞内钙浓度调节心肌 收缩和动脉肌肉组织的收缩。 因此，对Na/Ca交换功能的理解可以 深入了解导致发展的机制， 高血压 目前的工作旨在进一步 表征Na/Ca交换剂与不对称 载体的性质（对内部的不同反应性， 和细胞外配体）。 目的是确定， 不对称性是系统固有的，或者是 周围不同的离子和电环境 细胞的细胞内和细胞外阶段。 该分析将 允许在完整细胞中获得的数据和在细胞中获得的数据之间进行比较。 分离质膜的膜囊泡变宽 细胞和分子研究领域。

The Na/Ca exchange is a membrane bound mechanism responsible for net Ca extrusion from the cells. The importance of the Na/Ca exchange is evident from its ability to extrude large Ca loads; however, an additional fundamental aspect of this system results from its capacity, under certain conditions, to work in "reverse" facilitating the net Ca gain and the corresponding increase in the levels of ionized ıCa! of the cell. The relevance of this function is both physiological and pathological, for the intracellular Ca concentrations regulate cardiac muscle contraction and the contraction of the arterial musculature. Therefore, the understanding of the Na/Ca exchange function can provide insights into the mechanisms leading to the development of hypertension. The present work intends to further characterize the Na/Ca exchanger in relation to the asymmetric properties of the carrier (different reactivity towards intra- and extracellular ligands). The aim is to establish if that asymmetry is intrinsic to the system or a consequence of the different ionic and electrical environments surrounding the intra- and extracellular phases of the cell. This analysis will allow a comparison between data obtained in intact cells and in the membrane vesicles from isolated plasma membranes, widening the field of cellular and molecular research.