Mineralocorticosteroid

Mineralocorticosteroid is a class of steroid hormones produced in the adrenal cortex. The primary mineralocorticosteroid in humans is aldosterone. These hormones play a crucial role in regulating electrolyte balance, particularly sodium and potassium levels, and consequently, blood pressure.

Aldosterone's main target organ is the kidney, specifically the distal tubules and collecting ducts. Here, it acts to increase the reabsorption of sodium from the filtrate back into the bloodstream and to promote the excretion of potassium into the urine. This process helps to maintain the body's fluid and electrolyte homeostasis. The retention of sodium leads to water retention, which in turn increases blood volume and blood pressure.

The production of aldosterone is primarily regulated by the renin-angiotensin-aldosterone system (RAAS). When blood pressure or blood volume drops, the kidneys release renin, an enzyme that initiates a cascade leading to the production of angiotensin II. Angiotensin II then stimulates the adrenal cortex to secrete aldosterone. Conversely, high blood pressure and increased sodium levels suppress aldosterone release.

Disruptions in mineralocorticosteroid function can lead to various health conditions. Excessive aldosterone production, as seen in conditions like primary aldosteronism, can cause hypertension, hypokalemia (low potassium levels), and metabolic alkalosis. Conversely, insufficient aldosterone production, such as in Addison's disease, can result in hypotension, hyperkalemia, and hyponatremia (low sodium levels). Synthetic mineralocorticoids are used therapeutically to treat conditions where the body does not produce enough of these hormones.