SEROLOGICAL STUDIES ON CRYSTALLINE ADRENOCORTICOTROPHIC HORMONE: THE PRODUCTION OF ANTIADRENOCORTICOTROPHIN1

Abstract

A substance antagonistic to the normal action of the adrenocorticotrophic hormone (ACTH) has been demonstrated in the sera of mice treated by increasing daily doses of pure ACTH over a period of 25 days. These sera were titrated in biological assay expts. against standard doses of the hormone in question, and prevented the increase in adrenal wts. normally brought about by ACTH. The serological activity of antisera was demonstrated in both agglutination tests, in which collodion particles were used to increase the surface of the hormonal antigen, and in precipitin tests. Pure ACTH was used as the antigen and the above described sera as the source of antibody. Maximal serological activity was obtained 10 days after the course of injns. had been completed. The serological activity of the antiserum could be correlated with its biological activity.