EFFECT OF $gamma$-IRRADIATION ON THE ADRENO-CORTICAL FUNCTION OF RATS

Following Co/sup 60/ irradiation of 900 r, rats treated with ACTH survived 12.3 days while those without treatment lived only 8.3 days. On the second day the weight of the adrenal cortex was still within normal limits, but it tended to increase by the 4th day. At 4 hours after irradiation the ability of adrenocortical steroidogenesis in vitro was increased above normal, followed by a decrease 2 days later. When ACTH was injected after irradiation the excretion of formaldehydogenic steroids was lower than normal 2 to 5 days later. The decrease of WBC started 4 hours after irradiation, reaching 90% on the 4th day. Eosinophilic leukocytes almost disappeared immediately following irradiation. (Abstr. Japan Med., 1: No. 10, 1961).