Aldosterone vs ADH
Based on the provided articles, here are the key points about aldosterone versus antidiuretic hormone (ADH):
- **Aldosterone** is a mineralocorticoid hormone produced in the adrenal cortex that regulates sodium and water reabsorption in the kidney. Its main roles are:
- Increasing sodium reabsorption in the distal tubules [15]
- Increasing water reabsorption, leading to increased blood volume and blood pressure [15]
- Promoting potassium excretion [15]
- **ADH (vasopressin)** is an antidiuretic hormone produced in the hypothalamus that regulates water reabsorption in the kidney. Its main role is:
- Increasing water reabsorption in the collecting ducts by mobilizing aquaporin channels [16]
- While aldosterone and ADH both increase water reabsorption, they act on different nephron segments and through different mechanisms [16], [15].
- Aldosterone secretion is primarily regulated by the renin-angiotensin system, potassium levels, and ACTH [17], [18].
- ADH secretion is regulated by osmolality changes and blood volume/pressure changes detected by the hypothalamus [19].
- Aldosterone receptors decrease during maturation while ADH binding increases in the developing kidney, suggesting changing roles [19].
In summary, aldosterone and ADH are distinct hormones that regulate different aspects of sodium, water, and electrolyte balance through their effects on the nephron, though they both contribute to overall fluid homeostasis.
What is aldosterone and where is aldosterone produced?
Aldosterone is a steroid hormone. It is a key compound in the regulation of blood pressure. This steroid hormone is a mineralocorticoid and controls the ionic and water concentrations in the body [1, 2].
The primary synthesis of aldosterone takes place in the adrenal cortex. The center of production is the zona glomerulosa, which is the outside zone of the three zones in the adrenal gland [3].
However, there is growing evidence that aldosterone is also synthesized secondarily in other tissues, not only the adrenal gland. It is suspected that aldosterone can also be created by the heart and the vasculature [2, 4].
The body controls aldosterone levels via gene expression. When more aldosterone is needed, the cells in the zona glomerulosa express the gene CYP11B2. This gene encodes the enzyme responsible for aldosterone creation, aldosterone synthase.
The synthesis of aldosterone is controlled via two mechanisms. One is the renin-angiotensin system. In this regulatory process, molecules like renin, angiotensin, and potassium play an important role. The second mechanism that can cause aldosterone production is induction by adrenocorticotropin (ACTH) [3, 5].
What is the function of aldosterone?
Aldosterone’s main function is to control the ion and water balance in the body [6, 7, 8]. It primarily regulates the concentration of sodium and potassium. Via the movement of the first one, water is drawn back or out of the organism [8].
The primary effect of aldosterone is in the kidneys. In this naturally bilateral organ, the hormone induces an ionic exchange. Aldosterone activates the mineralocorticoid receptor, which triggers a cascade. The end effect of the later following reactions is the excretion of potassium and the reabsorption of sodium from the urine [9].
However, aldosterone also works in other organs. It also stimulates the absorption of sodium in the large intestine and salivary and sweat glands [10].
Especially with the control of the sodium concentration in the body, aldosterone also regulates the blood pressure. Therefore, it plays an important role in cardiovascular health. Elevated aldosterone levels can lead to hypertension and cardiovascular disease [11, 6]. Consider reading our other blog on how to lower aldosterone levels can be lowered naturally, if you have elevated aldosterone levels.
Aldosterone was also found to play a role in the regulation of inflammation and oxidative stress [8].
Which diseases are linked to increased aldosterone levels?
Based on the provided articles, increased aldosterone levels are linked to several diseases, including:
**Cardiovascular Diseases**
- [15], [16] Increased risk of all-cause and cardiovascular mortality
- [16] Higher risk of fatal stroke and sudden cardiac death
- [17], [18] Increased risk of cardiovascular events and complications
- [20], [19] Coronary artery disease, myocardial infarction, left ventricular hypertrophy, heart failure, atrial fibrillation
- [21] Concentric left ventricular hypertrophy
**Metabolic Disorders**
- [23], [22] Hypertension, obesity, metabolic syndrome, type 2 diabetes
- [24] Insulin resistance, impaired pancreatic beta-cell function
- [23] High triglycerides
**Kidney Diseases**
- [26], [25] Increased risk of chronic kidney disease progression and end-stage renal disease
- [21], [27] Kidney disease
**Other Conditions**
- [23] Central obesity
- [28] Carotid artery stenosis in hemodialysis patients
- [29] Aortic diseases in hypertensive patients
In summary, elevated aldosterone levels are associated with an increased risk of cardiovascular diseases, metabolic disorders (hypertension, obesity, diabetes), kidney diseases, and other conditions like central obesity and aortic diseases. [15], [16], [17], [18], [20], [19], [21], [23], [22], [24], [26], [25], [27], [28], [29]
What is ADH and where is ADH produced?
Antidiuretic hormone (ADH) is a peptide also known as arginine vasopressin (AVP) or simply vasopressin. It plays a crucial role in the regulation of the water balance in the body. Its effect makes the kidneys absorb more water, which can increase the amount of water found in the blood [12].
The site of production of ADH is neurons. Specifically, vasopressin is produced by the large neurons in the paraventricular and supraorbital nuclei. The synthesized vasopressin is then transported by neuronal projection and terminates in the pituitary gland. This is the place where ADH is secreted into the blood circulation [13].
What is the function of ADH?
ADH is crucial for maintaining the body's water balance, regulating blood pressure, and managing the body's sense of thirst.
The main function of the antidiuretic hormone is to balance the water concentration in the body. It regulates the water concentration by making the kidneys reabsorb more water [12].
The decision of whether to produce more ADH is made based on the ionic concentration in the blood. The release of vasopressin follows when the ionic concentration in the blood is high. There are two causes of such a situation. One is when high levels of sodium are found in the blood. The second situation is dehydration [12].
When one of these situations occurs, the released ADH travels by blood to the kidneys. Once there, it works on the cells, which form the collecting ducts. Vasopressin makes those cells express and transport through their membranes special water channels. These unique proteins are named aquaporins and allow the water to be absorbed back into the organism.
The absorption of water dilutes the blood ionic concentration and, therefore, inhibits vasopressin release. With the absorption of water, the blood pressure increases.
Additionally, ADH is a vasopressor. That means it causes vasoconstriction of the blood vessels. The reduced space for the blood after the constriction of the arteries increases blood pressure [14]. It is also a possible balance to the water inflow caused by ADH.
What diseases are linked to antidiuretic hormone?
Several diseases are linked to abnormal levels or regulation of antidiuretic hormone (ADH), also known as vasopressin. Here are some key diseases associated with ADH:
- **Syndrome of Inappropriate Antidiuretic Hormone (SIADH)**: This is a condition where there is excessive, unregulated secretion of ADH, leading to water retention and hyponatremia (low sodium levels). It can be caused by various factors like brain disorders, lung diseases, cancers [15], [16], medications, and others.
- **Diabetes Insipidus**: This disorder involves deficiency of ADH secretion or inability of kidneys to respond to ADH, resulting in excessive urination and dehydration. It can be central (pituitary problem) or nephrogenic (kidney problem) [17], [18].
- **Autosomal Dominant Polycystic Kidney Disease**: Increased levels of ADH contribute to cyst formation and disease progression [19].
- **Congestive Heart Failure**: ADH levels are often elevated, leading to fluid retention [20].
- **Cancers**: Certain cancers like small cell lung cancer [16], pancreatic cancer [16], and others can secrete ectopic ADH, causing SIADH [21].
- **Central Nervous System Disorders**: Conditions affecting the brain like infections, trauma, tumors, bleeding can disrupt ADH regulation, leading to SIADH or diabetes insipidus [15], [23], [22].
- **Respiratory Diseases**: Conditions like pneumonia, respiratory syncytial virus infections have been linked to elevated ADH levels [25], [24].
In summary, diseases affecting the hypothalamic-pituitary axis, kidneys, lungs, and certain cancers are commonly associated with dysregulation of ADH, leading to water balance disorders like SIADH or diabetes insipidus.