DETERMINATION OF ADRENOCORTICOTROPIN IN HUMAN URINE BY A BENZOIC-ACID ADSORPTION METHOD

Abstract

Benzoic-acid adsorption was successfully used for the extraction of adrenocorticotropin (ACTH) from human urine to be assayed by the ascorbic-acid depletion (AAD) method in hypophysectomized rats. In 25 normal subjects the AAD induced by 26 such extracts of 24-hour urine was 51 [plus or minus] 6.5 mg. per 100 g of adrenal (mean [plus or minus] S. E.), whereas the value for 10 extracts of 12-hour urine from 4 patients with Addison''s disease was 136 [plus or minus] 14.3 mg. (P > 0.001). The ACTH content of a normal 24-hour specimen of urine was therefore estimated to be approximately 0.25-0.5 milliunit, whereas in Addison''s disease the value may reach 1-2 milliunits per twelve hours. In 7 patients with hypopituitarism (12 extracts of 24-hour urine) and 12 patients receiving steroid therapy (18 extracts of 24-hour urine), significant decreases in ACTH were noted (23 [plus or minus] 8.7 mg., P < 0.02; and 15 [plus or minus] 8.0 mg., P < 0.01, respectively). In 5 cases of anorexia nervosa (5 extracts) there was no significant difference, either from normal subjects or from patients with hypopituitarism. Among 8 cases of Cushing''s syndrome (14 extracts), 2 of 6 cases with bilateral adrenal hyperplasia showed high AAD values, whereas both cases with unilateral adrenal adenoma showed low AAD values.