Effect of Chlorpromazine on Pituitary ACTH Secretion in the Dog

¹ From the Naval Medical Research Institute, National Naval Medical Center, Bethesda, Maryland

Effect of chlorpromazine on adrenal cortical function has been determined by measuring 17-hydroxycorticosteroids in adrenal venous blood of dogs following intravenous injection of the drug. It was found that approximately half of the animals had significant adrenal responses to the injection of 1.3–3.3 mg./kg of chlorpromazine, and that all animals responded to dosages of 3.5 mg./kg and above. The adrenal response was abolished by hypophysectomy, ruling out a direct action of the drug on the adrenal gland. The response was unaffected by maintaining high peripheral blood levels of hydrocortisone. These observations suggest that chlorpromazine stimulates the release of ACTH from the adenohypophysis.