Mineralocorticoids and mineralocorticoid antagonists

With mineralocorticoids, “corticoids” refers to the steroid hormones produced by the adrenal cortex, and “mineral” refers to how these hormones regulate sodium reabsorption and potassium excretion in the distal convoluted and collecting tubules of the kidney.

Aldosterone is the major natural mineralocorticoid in humans and there are two major classes of medications targeting the actions of mineralocorticoids: mineralocorticoid-receptor agonists, which mimic the role of aldosterone; and mineralocorticoid-receptor antagonists, that block the action of aldosterone.

Alright, but first things first.

Aldosterone is part of a hormone family, or axis, that works together and is called the renin-angiotensin-aldosterone system.

Normally, when the blood pressure is low, the kidney gets less blood, which causes it to release renin into the blood.

Renin converts a prohormone called angiotensinogen into angiotensin I, and another enzyme called angiotensin converting enzyme, or ACE, converts angiotensin I into angiotensin II.

Angiotensin II has many effects like causing vasoconstriction and stimulating the release of antidiuretic hormone from the pituitary glands.

In the adrenal glands, it triggers the secretion of aldosterone.

In the kidneys, aldosterone affects two types of cells along the distal convoluted and collecting tubule of the nephron.

First, it binds to mineralocorticoid receptors in the cytoplasm of principal cells, forming an aldosterone-receptor complex.

This complex is translocated to the nucleus of the cell, where it enhances two types of cells along the distal convoluted and collecting tubule of the nephron.