Final answer:
Loop diuretics inhibit the reabsorption of Na+ and Cl- ions in the nephron, leading to an increase in the excretion of K+ ions in urine.
Step-by-step explanation:
Loop diuretics inhibit the reabsorption of Na+ and Cl- ions by the ascending limb of the loop of Henle in the nephron. This inhibition leads to an increase in the amount of Na+ and Cl- ions excreted in the urine. Since K+ ions are excreted when Na+ is retained, the increase in urine volume caused by loop diuretics also results in an increase in the excretion of K+ ions.