Adrenal Response of Young Chickens to Adrenocorticotropic Hormone as Influenced by Dosage and Frequency of Injection

Abstract

ADRENOCORTICOTROPIC hormone (ACTH) has been reported to disappear rapidly from the plasma of mammals. The half-time for the disappearance of ACTH from the plasma of rat intravenously administered ACTH has been found by Greenspan et al. (1950) to be 51/2 minutes. In conjunction with other studies in this laboratory, it was necessary to determine how daily dosage and injection frequency influenced adrenal response of chickens to ACTH. As criteria of response, the following were observed: (a) body weight gains, and (b) the changes occurring in the weight and histology of the adrenal and the bursa of Fabricius. Changes in weight and histology of the bursa of Fabricius seem to be closely related to adrenal activity (Garren and Barber, 1955; Garren, 1957). MATERIALS AND METHODS All preparations of ACTH were given by intramuscular injection. The first injection was given in the right pectoral muscle and thereafter alternate sides of the breast …