Lack of Correlation of Eosinopenic and Adrenal Ascorbic Acid-Depleting Activities of Various Adrenocorticotropic Preparations.

Abstract

Equivalent dose levels by wt. of various ACTH prepns. have been compared on the basis of their eosinopenic activity (EA) in normal and hypophysecto-mized rats with the adrenal ascorbic acid-depleting activity (AAA) in hypophysectomized rats. The data presented have been interpreted as indicating that: (1) No correlation exists between the EA and AAA of various ACTK fractions as . tested either in normal or hypophysectomized rats. (2) EA in normal rats is not necessarily correlated with EA of the same prepns. as tested in hypophysectomized rats. (3) Reduction of AAA by treatment with NaOH-heat under the conditions employed does not inactivate EA, suggesting that EA may be a separate and more stable component of the ACTH prepns. Neither AAA nor EA was influenced by HCl-heat treatment in these expts. (4) No ACTH compound has been tested which is completely free of AAA and yet exhioits EA, although the converse has been observed. (5) Some evidence suggests the presence of an eosinophilic component in certain ACTH prepns.