Summary
This study is aimed at elucidating the mechanism of a paradoxical rise in plasma ACTH
levels in response to glucocorticoids, observed by several authors in bilaterally
adrenal-ectomized patients with Cushing's disease. Six control subjects and fourteen
patients bilaterally adrenalectomized for Cushing's disease were given a dose of 200
mg hydrocortisone sodium succinate by a 3-5 min i.v. injection. Plasma ACTH (in 6
patients), serum cortisol, growth hormone (GH) and insulin and blood glucose levels
were estimated at 0, 30, 60, 90, and 120 minutes. The administration of hydrocortisone
significantly suppressed plasma ACTH levels only at 60 min. In one case a slight rise
in ACTH level during the test was observed. A significant fall in blood glucose levels
was found only in the adrenalectomized patients. No significant changes in serum insulin
and GH levels were noted. The possible mechanisms are discussed, especially the potential
role of transient glucose deficiency in the pathophysiology of plasma ACTH increase
in response to hydrocortisone in the bilaterally adrenalectomized patients.
Key-Words
Bilateral Adrenalectomy
-
Cortisone Withdrawal
-
Plasma ACTH
-
Serum Growth Hormone
-
Serum Insulin
-
Blood Glucose
