How do kidneys typically respond to metabolic alkalosis?

In the case of metabolic alkalosis, the kidneys respond by adjusting the reabsorption of bicarbonate (HCO3-). When the body experiences a rise in blood pH due to alkalosis, the kidneys work to bring the pH back to a normal level. One of the mechanisms for this adjustment is to decrease the reabsorption of bicarbonate in the renal tubules.

By reducing the amount of bicarbonate that is reabsorbed back into the bloodstream, the kidneys effectively allow more bicarbonate to be excreted in the urine. This loss of bicarbonate helps to lower the systemic bicarbonate levels and, consequently, reduce the blood pH towards normal levels.

This physiological response is essential because it counteracts the alkalotic state and helps restore homeostasis. By expelling excess bicarbonate, the kidneys play a crucial role in maintaining acid-base balance in the body during conditions of metabolic alkalosis.