Interrelationship between the membrane potential of adrenocorticocytes and functional activity of the adrenal glands in adult and old rats

Experiments on adult (5–7 months old) and old (28–30 months old) male rats reveal that ACTH induces a hyperpolarization of the plasma membrane of adrenocorticocytes from the fasciculate zone in both age groups of animals 24 hours after a single administration of the hormone. Actinomycin D, an inhibitor of protein synthesis, prevents the development of hyperpolarization.