Mineralocorticoids

They are also steroid hormones and two main Mineralocorticoids are aldosterone and 11-deoxycorticosterone.

Source of secretion:

They are secreted by zona glomerulosa of adrenal cortex and produced from cholesterol.

Chemistry and structure:

They are C21 steroids containing 21 carbon atoms. 90% of mineralocorticoid activity is shown by aldosterone.

Metabolic roles:

The main role of Mineralocorticoids is to balance the electrolytes in the body. Some of the metabolic roles are as shown below:

1. Effect on sodium reabsorption:

• Aldosterone acts on distal convoluted tubule and collecting duct and increases the reabsorption of sodium ions.

2. Effect on extracellular fluids:

• Along with the sodium , water also gets reabsorbed from renal tubules. This can lead to increase in extracellular volume.

3. Effect on blood pressure:

• The Mineralocorticoids cause increase in extracellular fluid volume and blood volume. This can ultimately lead to high blood pressure.
• To counterbalance this, atrial natriuretc peptide is secreted from atrial muscle of the heart and cause sodium excretion.

4. Effect on potassium ions:

• Aldosterone increases the potassium ions excretion through the renal tubules.

5. Effect on intestines:

• Aldosterone enhances the absorption of sodium ions from the intestine also.