QS Study

Aldosterone is produced in the cortex of the adrenal glands, which are located above the kidneys. It is essential for sodium conservation in the kidney, salivary glands, sweat glands, and colon. It affects the body’s ability to regulate blood pressure. It balances the levels of sodium and potassium in your body.

Functions of the aldosterone – The hormone acts primarily in the functional unit of the kidneys to aid in the maintenance of sodium, secretion of potassium, water retention and to steady blood pressure.

(1) Renal and circulatory effects of aldosterone:

a) Increased renal tubular reabsorption of sodium and simultaneously increase secretion of K+.

b) Increased ECF volume and arterial pressure.

c) Excess aldosterone causes hypokalemia and muscle weakness.

d) Excess aldosterone causes the increase in tubular H+ secretion resulting in mild alkalosis.

e) Decreased aldosterone may cause circulatory shock.

f) Hypokalaemia and cardiac toxicity by the little aldosterone.

Fig: Aldosterone helps and maintains blood pressure and blood volume.

(2) Effects of aldosterone on sweat gland and salivary gland.

Aldosterone greatly increases the reabsorption of Na+ and Cl and secretion of K+ by the duct of sweat and salivary gland.

(3) Effect of aldosterone on GIT:

↑ Na+ absorption by the intestine especially colon, which prevents loss of Na+ in the stool.

(4) Biological function

  • It stimulates the secretion of K+ into the tubular lumen.
  • It stimulates Na+ and water reabsorption from the gut, salivary and sweat glands in exchange for K+.
  • It stimulates secretion of H+ via the H+/ATPase in the intercalated cells of the cortical collecting tubules.