ADH Vs Aldosterone: Definition, Functions and Differences
The endocrine system consists of a number of ductless glands which produces chemical substances, known as a hormone. Hormones work individually in very low concentration and take part in different chemical reactions or can act as a catalyst. They are generally protein in nature and never stored in any other place for future use except the secretary glands or tissues.
ADH (Anti-diuretic Hormone) is also known as Vasopressin, arginine vasopressin (AVP) or argipressin. It is a neuro-secretary peptide hormone comes from the hypothalamus and it is released by the posterior pituitary gland. It is responsible for many metabolic processes of the body. Just beneath the hypothalamus, ADH is secreted into the blood. It is protein in nature and contains nine amino acids such as tyrosine, phenylalanine, glutamine, asparagine, proline, arginine, glycine, cysteine, etc. It is stored in granules accumulated at the axon terminals situated in the posterior pituitary. This hormone is transmitted from the axon terminal of the neuron to the capillary beds in the pars nervosa of the posterior pituitary.
Chemical Structure of ADH with Labeled Amino Acids
Aldosterone is a mineralocorticoid steroidal hormone like cortisol which is made of cholesterol and secreted from the adrenal cortex of the adrenal gland.
Chemical Structure of Aldosterone
In the body, the two hormones (ADH and Aldosterone) are released under low blood pressure conditions. They also act on the distal convoluted tubules and collecting tubules of the nephron. ADH makes the distal convoluted tubules (DCT) more porous to water while aldosterone makes the distal convoluted tubules (DCT) more penetrable to mineral particles, for example, sodium ions which increase the water re-absorption by making an osmotic pressure.
Functions of ADH
Role of Antidiuretic hormone (ADH)
Functions of Aldosterone
Aldosterone Feedback Loop
Difference between ADH and Aldosterone
Some important differences between ADH and Aldosterone are stated in the following table:
ADH | Aldosterone |
|---|---|
ADH (anti-diuretic hormone) is a peptide hormone. | Aldosterone is a corticosteroid hormone. |
It is secreted by the posterior pituitary gland. | It is synthesized and secreted by the adrenal cortex. |
It prevents the production of dilute urine. | It stimulates the absorption of sodium by the nephron to maintain water and salt balance. |
It is secreted when the body is dehydrated. | It is secreted when blood pressure is low. |
It increases blood pressure through vasoconstriction. | It has no effect on the blood vessels. |
It makes the distal convoluted tubule (DCT) and collecting tubules (CT) more permeable to water. | It makes the distal convoluted tubule (DCT) and collecting tubules (CT) more permeable to sodium ions. |
It stimulates the kidney to reabsorb more water. | It increases the NaCl and water absorption capacity of the kidney by making an osmotic pressure. |
It is discharged in response to hypertonicity of the blood and in response to cholecystokinin. | It is discharged in response to the increased plasma angiotensin III, ACTH, serum potassium concentrations, etc. |
ADH is inhibited by Diuretics such as alcohol (CH3-CH2-OH). | It is inhibited by ACE (Angiotensin-converting enzyme), dopamine, and atrial natriuretic hormone (ANH). |
Some Similarities between ADH and Aldosterone
Also read: Vitamins : Classification, Functions and Deficiency Symptoms
