What is the key effect of carbonic anhydrase inhibitors on renal function?

Carbonic anhydrase inhibitors primarily affect renal function by promoting bicarbonate excretion. These agents work by inhibiting the enzyme carbonic anhydrase, which is crucial in the reabsorption of bicarbonate in the proximal tubule of the nephron. When this enzyme is inhibited, bicarbonate is not reabsorbed effectively, leading to increased bicarbonate levels in the urine. As a result, this process also facilitates the excretion of sodium, as sodium and bicarbonate are usually reabsorbed together. The overall effect on renal function is a reduction in the bicarbonate concentration in the blood, leading to a mild metabolic acidosis if used over extended periods. This mechanism is the basis for their diuretic effect and makes bicarbonate excretion the key response influenced by carbonic anhydrase inhibitors.