Potassium sparing diuretics acts On:
These are either aldosterone antagonist or directly inhibit Na+ channels in DT and CD cells to indirectly conserve K+. Potassium-sparing diuretics - Spironolactone( Aldosterone antagonist) Amiloride, Triamterene ( inhibit renal epithelial Na channel ) Mechanism of action: aldosterone binds to aldosterone receptor first in the collecting ducts- AR complex induces growth of ENAC or stimulation of ENAC- epithelial sodium channels- leading to loss of potassium in the urine and sparing of sodium in the plasma now if spironolactone is administered, blocks AR complex- opp actions will be seen- potassium will be spared inside the body leading to loss of sodium in the urine ( Essentials of Medical Pharmacology, K.D Tripathi,6th edition )
Na+ K+ pump
Aldosterone receptor
Carbonic anhydrase
Na+ Cl- sympoer
Kidney