Water is vital to life and a major component of the human body. To maintain homeostasis, our bodies must regulate the amount of water through various chemical, hormonal and physiological methods. Salt and anti-diuretic hormone are two compounds that are highly involved in the regulation of water within our bodies.
Excessive Salt
Most people are familiar with common salt, otherwise known as sodium chloride, or table salt. Table salt has many useful purposes in industry, medicine, and dietary nutrition. It has become a major seasoning and flavoring ingredient in most recipes and prepared foods. Unfortunately, excessive salt intake can cause an increase in blood volume that exacerbates conditions including high blood pressure, congestive heart failure and fluid retention.
How Sodium Is Removed From Our Bodies
Although some sodium and water leaves our bodies in the form of perspiration, the majority of salt and water is removed by the kidneys. A general rule in biology is that water tends to follow wherever salt goes. As salt is filtered by the kidneys, water flows into the renal tubules and both are later excreted as urine. During this process, there is some resorption of both salt and water. The regulation of water and salt within the body involves a complex interaction between both hormonal and physiological effects.
Anti-Diuretic Hormone
As its name implies, the primary role of anti-diuretic hormone is to promote the resorption of water from the renal tubules back into the body. Anti-diuretic hormone, also commonly known as vasopressin, signals the opening of aquaporins, channels that allow water to flow across the tubular membrane back into systemic blood vessels. The resulting effect is that water is retained within the body and vascular volume is increased.
Salt and Anti-Diuretic Hormone
As expected, the secretion of anti-diuretic hormone is stimulated by circumstances that favor the body to conserve and retain water. These situations may include dehydration, low blood pressure and an increasing concentration of solutes within the bloodstream. Sodium and chloride are both solutes that are found within the bloodstream. Excessive dietary intake causes a rise in concentration of these solutes. In an effort to preserve homeostasis, the body secretes anti-diuretic hormone to promote the absorption and retention of free water from the kidneys. A patient with concerns regarding salt intake should speak with his physician.
