ADRENOCORTICOTROPIC HORMONE IN HUMAN PLASMA*

Abstract
ACTH was assayed by the measurement of corticosterone in the adrenal venous plasma of the hypophysectomized rat after the intravenous administration of the test sample. The assay is more sensitive than previous techniques, enabling the detection of .04 mu of ACTH. Plasma from normal subjects was found to contain ACTH in levels ranging from .4 to 1.0 mU per 100 ml. Patients with Cushing''s syndrome due to adrenal cortical hyperplasia had normal levels. All the patients with hypoadrenalcorticism had elevated levels, and no ACTH was detected in patients with panhypopituitarism. After administration of methopyrapone (SU-4885) or bacterial pyrogen, no increase in plasma ACTH was found.