[Regulation of corticoliberin and corticotropin incretion in old age]

Experiments on adult and old rats have shown age-related decrease of the CRF incretion in the hypothalamus, weakening of its response to dexamethasone, as well as a decrease of receptor corticosterone binding. Against this background in the hypophysis of old rats sensitivity ox CRF and serotonin increased, in stress the same content of ACTH as in adult rats secreted, it more markedly reacted to dexamethasone, and receptor of corticosterone binding increased in hypophysis. In old age, the role of hypophyseal link in control of the adrenocortical function is assumed to increase in stress.