INSULIN STIMULATION TESTS IN PITUITARY DEPENDENT CUSHING'S SYNDROME AFTER COMPLETE ADRENALECTOMY

Abstract
In a group of 6 euadrenal patients, previously treated by complete adrenalectomy for pituitary dependent Cushing''s syndrome, the stress stimulus of insulin-induced hypoglycemia is followed by a plasma ACTH response which is of similar magnitude as the response obtained with lysine-vasopressin. The CNS-pituitary axis is basically normal in pituitary dependent Cushing''s syndrome as assessed by insulin induced hypoglycemia. Non-responsiveness of the pituitary-adrenocortical system to insulin-induced hypoglycemia in untreated patients with pituitary dependent Cushing''s syndrome does not represent a fundamental defect of the stress mechanism, but is due to hypercorticism per se.