The second half of the distal tubule and the cortical collecting tubule of kidneys are equipped with the Principal and Intercalated cells. Of these, the Principal cells reabsorb Na ⁺ and excrete K ⁺ and are equipped with receptors for the hormone aldosterone. In primary hyperaldosteronism disease, there is an excess production of aldosterone which causes high blood pressure and K ⁺ imbalance. Spironolactone, a diuret