BLOOD CORTICOTROPHIN IN NORMAL ADULTS AND IN PATIENTS WITH CUSHING'S SYNDROME

Abstract

An oxycellulose adsorption-HC1 elution procedure has been used to concentrate corticotrophin (ACTH) from about 1000 ml normal pooled human blood or 500 ml blood from patients with Cushing''s syndrome. The concentrates were bioassayed by measuring their adrenal ascorbic acid depleting action in cortisol-treated rats. Satisfactory recovery figures were obtained for the concentration of 2nd International Standard for ACTH added to out-of-date blood-bank blood or to blood from a hypophysectomized patient. Normal blood ACTH levels are reported from 8 estimations each on pooled blood from 2-3 individuals. Mean normal ACTH was 0.7 mU per 100 ml blood (range 0.60-1.2 mU). 11 patients with Cushing''s syndrome were investigated. These included non-treated cases with adrenal hyper-plasia and post-adrenalectomy cases with recurrence of Cushingoid symptoms in the presence of a pituitary tumour. In both groups, mean blood ACTH values were three to four times normal.