Abstract
SUMMARY: The presence of an adrenocorticotrophic hormone (ACTH) has been demonstrated in the pituitary of the Arctic cod, Gadus morhua L. using standard assays with rats. Positive results were obtained in assays by the Sayers method of measuring the depletion of adrenal ascorbic acid in hypophysectomized rats, and by that of maintenance of adrenal weight, also in hypophysectomized rats. Adrenocorticotrophic activity was present in samples from both immature and mature cod. A tentative calculation suggested that the adrenocorticotrophic potency of one sample of cod pituitary was approx. 3·5 mu. ACTH/mg.