Increased levels of aldosterone lead to sodium retention and increased blood volume, contributing to elevated blood pressure, a hallmark of hypertension.
Aldosterone is a vital hormone produced in the adrenal cortex, part of the adrenal glands located above the kidneys. It belongs to a class of hormones known as mineralocorticoids and plays a key role in regulating blood pressure and electrolyte balance.
The primary function of aldosterone is to increase sodium reabsorption and potassium excretion by the kidneys. This process occurs in the distal tubules and collecting ducts of the nephron, which is the functional unit of the kidney. By promoting sodium retention, aldosterone helps to increase blood volume and, consequently, blood pressure. It also helps maintain electrolyte balance by regulating blood levels of sodium and potassium.
Aldosterone secretion is primarily regulated by the renin-angiotensin-aldosterone system (RAAS), which responds to changes in blood pressure, blood volume, and plasma sodium levels. When blood pressure or sodium levels are low, the kidneys release renin, which ultimately leads to increased production of aldosterone. Additionally, elevated blood potassium levels can directly stimulate aldosterone secretion.
Imbalances in aldosterone production can lead to various health conditions. Hyperaldosteronism, characterized by excessive aldosterone production, can cause hypertension and hypokalemia. Conversely, hypoaldosteronism, or insufficient aldosterone production, can result in low blood pressure, hyperkalemia, and metabolic acidosis.
The RAAS begins with the release of renin from the kidneys, which converts angiotensinogen to angiotensin I. Angiotensin I is then converted to angiotensin II, which stimulates the adrenal glands to release aldosterone. This hormone cascade is essential for maintaining blood pressure and electrolyte balance.
Increased levels of aldosterone lead to sodium retention and increased blood volume, contributing to elevated blood pressure, a hallmark of hypertension.