Numerous studies have correlated dietary salt intake with hypertension and harmful cardiovascular effects. People who develop hypertension as a result of high salt intake have kidneys with limited capacity to excrete this daily intake and tend to retain salt in the skin and other extracellular compartments (Titze et al, 2003). Aldosterone plays an important role in regulating the body's salt and water balance by controlling the activity of epithelial sodium channels in the renal collecting duct and can cause swelling and stiffening of the vessel while also altering its production of nitric oxide, which affects the vessel's ability to vasodilate. (Nagata, 2006). Salt consumption results in a transient increase in plasma volume and a subsequent increase in blood pressure as extracellular volume returns to normal (Hamlyn et al, 1986). Recently, it has been claimed that plasma sodium plays a primary role in blood pressure control due to its discovered increase (23–69 mg) in people with hypertension (He et al, 2004). From this discovery came the idea that vascular endothelium may participate in sodium-mediated blood vessel function through the response of endothelial cells to aldosterone. To support the contention that endothelial stiffness is influenced by changes in plasma concentration, atomic force microscopy which measures endothelial cell stiffness was used to see what occurs in the absence of aldosterone. Endothelial cell samples were maintained in two different environments: an infusion of eplerenone, which created a culture medium without aldosterone, and another medium containing aldosterone. The results showed that the stiffness and deformability of endothelial cells remained unchanged in an environment without aldosterone...... middle of paper ...... that sodium ingestion (particularly high content) passes through the compartments extracellular, including the vascular system before being eliminated by the kidneys. An acute increase in plasma sodium concentration can alter the mechanical properties of the vascular endothelium, as long as aldosterone is present. Aldosterone not only plays a major role in adjusting the transport of sodium and potassium in the kidneys but also in the cardiovascular system. Sodium accumulates in the extracellular space when the kidneys cannot adequately adjust salt excretion to salt absorption and/or when aldosterone concentration increases, leading to an increase in plasma sodium concentration. An important finding of these studies was the observed effects of amiloride, which blocked sodium channels and prevented an increase in stiffness by reversing the increase in cell volume and pressure...