Abstract
Rats were handled for 3 min daily for 3 weeks before or after weaning or were left totally undisturbed. At 80 days of age, animals from each group were selected for corticosterone half‐life determination. Adrenal tissue from the remaining animals was incubated in vitro in the presence or absence of ACTH. Handled and unmanipulated animals did not differ in half‐life or in adrenocortical output. These data do not support the hypothesis that the reduced adrenocortical reactivity that results from manipulating animals is due to either the metabolism of corticosterone or the response of the adrenal cortex to ACTH.