Final answer:
ADH binds to V1 and V2 receptors, with V2 receptors increasing water reabsorption in the kidneys and V1 receptors causing vasoconstriction, both helping to regulate blood pressure and fluid balance.
Step-by-step explanation:
When antidiuretic hormone (ADH), also known as vasopressin, is released, it binds to V1 and V2 receptors which have different functions. The binding of ADH to V2 receptors on the cells of the collecting ducts in the kidneys promotes water reabsorption by causing aquaporins to be inserted into the plasma membrane. This action reduces urine volume and increases blood volume and pressure.
On the other hand, when ADH binds to V1 receptors, it causes vasoconstriction of smooth muscle in blood vessels, leading to an increase in blood pressure. Both actions of ADH are crucial in maintaining the body's fluid balance, particularly during dehydration or blood loss.