aldosterone

(noun)

A corticoid hormone, secreted by the adrenal cortex, that regulates the balance of sodium and potassium and thus water balance levels, in the body.

Related Terms

(noun)

A mineralocorticoid hormone, secreted by the adrenal cortex, that regulates the balance of sodium and potassium in the body.

Related Terms

Examples of aldosterone in the following topics:

  • Sodium Balance Regulation

    • In states of sodium depletion aldosterone levels increase.
    • In states of sodium excess aldosterone levels decrease.
    • The major physiological controller of aldosterone secretion is the plasma angiotensin II level which increases aldosterone secretion.
    • A high plasma potassium also increases aldosterone secretion because besides retaining Na+ high plasma aldosterone causes K+ loss by the kidney.
    • In states of sodium depletion, aldosterone levels increase, and in states of sodium excess, aldosterone levels decrease.

  • Other Hormonal Controls for Osmoregulation

    • One type of mineralocorticoid, known as aldosterone, regulates sodium levels in the blood.
    • Aldosterone also stimulates potassium secretion concurrently with sodium reabsorption.
    • Patients who have Addison's disease have a failing adrenal cortex and cannot produce aldosterone.
    • Its actions suppress the actions of aldosterone, ADH, and renin.
    • The renin-angiotensin-aldosterone system increases blood pressure and volume.

  • Regulation of Water Output

    • The hormones ADH (anti-diuretic hormone, also known as vasopressin) and aldosterone, a hormone created by the renin-angiotensin system play a major role in this.
    • Aldosterone is a steroid hormone (corticoid) produced at the end of the renin-angiotensin system.
    • Angiotensin II has a variety of effects (such as increasing thirst) but it also causes release of aldosterone from the adrenal cortex.
    • Aldosterone has a number of effects involved in the regulation of water output.
    • Aldosterone will also cause a similar ion balancing effect in the colon and salivary glands as well.

  • Hormonal Regulation of the Excretory System

    • The contrasting actions of antidiruetic hormone and aldosterone work to regulate the level of water in the body.
    • Aldosterone release is stimulated by a decrease in blood sodium levels, blood volume, or blood pressure, or an increase in blood potassium levels.
    • Aldosterone production can be stimulated by low blood pressure, which triggers a sequence of chemical release .
    • When blood pressure drops, the renin-angiotensin-aldosterone system (RAAS) is activated.
    • ADH and aldosterone increase blood pressure and volume.

  • Adrenal Cortex

    • The outermost layer, the zona glomerulosa is the main site for production of mineralocorticoids, mainly aldosterone, which is largely responsible for the long-term regulation of blood pressure.
    • The major stimulus to produce aldosterone is angiotensin II while ACTH from the pituitary only produces a transient effect.
    • The primary mineralocorticoid is aldosterone.
    • Aldosterone is secreted in response to high extracellular potassium levels, low extracellular sodium levels, and low fluid levels and blood volume.
    • Aldosterone affects metabolism in different ways:

  • Long-Term Renal Regulation

    • A key modulator of blood viscosity is the renin-angiotensin system (RAS) or the renin-angiotensin-aldosterone system (RAAS), a hormone system that regulates blood pressure and water balance.
    • Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex.
    • Aldosterone causes the tubules of the kidneys to increase the reabsorption of sodium and water into the blood.
    • If the renin-angiotensin-aldosterone system is too active, blood pressure will be too high.

  • Organs with Secondary Endocrine Functions

    • ANP also reduces the amounts of renin released by the kidneys and aldosterone released by the adrenal cortex, further preventing the retention of water.
    • Renin, released in response to decreased blood volume or pressure, is part of the renin-angiotensin-aldosterone system that leads to the release of aldosterone.
    • Aldosterone then causes the retention of Na+ and water, raising blood volume.

  • Adrenal Glands

    • The main mineralocorticoid is aldosterone, which regulates the concentration of sodium ions in urine, sweat, pancreas, and saliva.
    • Aldosterone release from the adrenal cortex is stimulated by a decrease in blood concentrations of sodium ions, blood volume, or blood pressure, or by an increase in blood potassium levels.
    • Aldosterone is one example of a mineralcorticoid.
    • Angiotensin stimulates aldosterone secretion.
    • Aldosterone, the major mineralcorticoid, stimulates the cells of the distal convoluted tubules of the kidneys to decrease re-absorption of potassium and increase re-absorption of sodium.

  • Adrenal Gland Disorders

    • Adrenal insufficiency is a condition in which the adrenal glands do not produce adequate amounts of cortisol and/or aldosterone.
    • Adrenal insufficiency is a condition in which the adrenal glands, located above the kidneys , do not produce adequate amounts of steroid hormones, primarily cortisol, but may also include impaired aldosterone production which regulates sodium, potassium, and water retention.

  • Nonrespiratory Air Movements

    • In general, more ACE leads to more angiotensin II, which leads to more aldosterone, which leads to more retained water through sodium reabsorption in the kidney, which leads to increased blood volume and blood pressure.
    • The renin-angiotensin-aldosterone system is dependent on ACE from the lungs to regulate blood pressure.