CORTICOTROPHIN-RELEASING FACTOR ACTIVITY IN HYPOTHALAMIC EXTRACTS OF MAN

Abstract

ABSTRACT Hypothalamic extracts of human corpses of both sexes were tested for corticotrophin-releasing activity using rats which were hypothalamus-blocked with chlorpromazine, morphine, and Nembutal. The released ACTH was determined by fluorometric measurement of the increase of plasma corticosterone. Fractions 2 and 4 (Sephadex G-25 chromatography) showed corticotrophin-releasing activity, whereas fraction 3 which had gonadotrophin-releasing activity in former studies, showed none. In hypophysectomized rats, fractions 2 and 4 showed no ACTH-contamination and contained activity definitely different from vasopressin. Fraction 4 showed a linear log dose-response between 0.05 and 1.25 hypothalamic equivalents. It is concluded that these fractions are identical to CRF and can be well separated from the gonadotrophin-releasing factors.