The Delayed Effect of Acth Administration on the Plasma Corticoid Level of Normal Elderly Persons and Patients With Chronic Brain Syndrome*

A bstract : ACTH (40 I.U.) was injected intramuscularly into 30 normal elderly subjects (N), 30 patients with senile psychosis (S), and 30 patients with psychosis due to arteriosclerosis (CAS). The ages of the subjects ranged between 64 and 97 years, the mean ages of the N, S and CAS groups being 74, 79 and 77 years respectively. Blood samples were drawn immediately before the injection and at eight and ten hours afterwards. The plasma cortisol and corticosterone (PC) concentrations were determined by the method of Murphy et al. The time curves for the three groups differed significantly. The PC values were highest in the S patients and lowest in the N subjects at eight and ten hours. Differences between the S and CAS patients were statistically significant, as were the differences between the CAS patients and the N subjects. There was no reliable difference in PC levels between men and women. The PC values in eight and ten hours were significantly higher than those at the zero hour; in addition, the eight‐hour value was significantly higher than the ten‐hour one. However, the sex × time and the disease × sex × time interactions were not significant. The results of these studies provide at least one explanation of why patients with senile or arteriosclerotic brain syndrome are more reactive to stress than are normal aged subjects—their adrenal cortices are more reactive.