USE OF LYSIN-VASOPRESSIN IN THE DIFFERENTIAL DIAGNOSIS OF CUSHING'S SYNDROME

The plasma cortisol response following intramuscular administration of synthetic lysin-8-vasopressin was measured in nine patients suffering from various forms of Cushing's syndrome. A significant response was obtained in six patients with pituitary dependent Cushing's syndrome, whereas no response was observed in two patients with Cushing's syndrome due to an adrenal tumour and in one patient with an ectopic ACTH syndrome. The possible technical errors which are inherent to this test are discussed in relation to a few contradicting observations from the literature.In three patients with pituitary dependent Cushing's syndrome the use of lysin-8-vasopressin and metyrapone is compared in the evaluation of pituitary-adrenal reserve capacity during various stages of treatment by unilateral adrenalectomy and external pituitary irradiation.