Question

Chronically-high levels of glucocorticoids like cortisone can also be the result of an overactive pituitary gland or adrenal gland. How can increased activity of each of these glands lead to an overproduction of glucocorticoids?

To determine which gland is abnormally over-active in a particular patient, doctors can use the drug dexamethasone, a synthetic glucocorticoid that blocks ACTH release. If administration of dexamethasone has no effect on cortisone levels in the blood, what would this suggest? Explain your logic.