Friedman S M
Blood Vessels. 1979;16(1):2-16. doi: 10.1159/000158185.
Extracellular Na can be accurately partitioned into free and bound components; the latter component is directly related to the hydration and stiffness of the vascular wall. Cell Na can be similarly partitioned: [Na+]i is about 10mM and the transmembrane gradient about 15:1 in a physiological medium. The transmembrane gradient remains constant over a wide range of change in [Na+]0. Although active Na transport is largely responsible for developing the transmembrane ion distribution pattern, the membrane potential depends mainly on movements of K+ and C1-. No certain direct role can be assigned to Na+ in short-term vasoconstriction, but an indirect role through the regulation of catecholamine release and uptake is now established. There is evidence that the entry of Na+ into cells plays a fundamental role in the protein-synthesizing activity of the vascular smooth muscle cell and is thereby involved in the longer term determination of peripheral vascular resistance.
细胞外钠可精确地分为游离成分和结合成分；后者与血管壁的水合作用和硬度直接相关。细胞内钠也可作类似划分：在生理介质中，细胞内[Na⁺]约为10mM，跨膜梯度约为15:1。跨膜梯度在[Na⁺]₀的广泛变化范围内保持恒定。虽然主动钠转运在很大程度上决定了跨膜离子分布模式，但膜电位主要取决于K⁺和Cl⁻的移动。在短期血管收缩中，无法确定Na⁺有某种直接作用，但现在已证实其通过调节儿茶酚胺的释放和摄取起间接作用。有证据表明，Na⁺进入细胞在血管平滑肌细胞的蛋白质合成活性中起基本作用，从而参与外周血管阻力的长期调节。
