PSYCHOLOGICAL DISTURBANCE ALTERS THYMIC AND ADRENAL-HORMONE SECRETIONIN A PARALLEL BUT INDEPENDENT MANNER

Thymosin-alpha1 (thymosin(alpha 1)) and cortisol levels were evaluated in juvenile squirrel monkeys to investigate the influence of psycholo gical disturbance on thymic and adrenal hormone activity. Hormone leve ls were assessed in peripheral circulation following removal of monkey s from their social group to establish the time course of thymosin and cortisol alterations. Thymosin(alpha 1) was significantly decreased a fter social separation in association with increased adrenocortical ac tivity, especially during the first day after being housed alone. The temporal pattern suggested that both hormone systems are involved in t he acute inhibition of functional immunity observed following this typ e of psychological disturbance. A second study verified that the decre ment in thymosin(alpha 1) levels was replicable and also sensitive to psychosocial factors that influence the level of induced disturbance. In addition, changes in thymosin secretion could be attenuated partial ly by pharmacological inhibition of the cortisol response and opiate h ormone action. Nevertheless, the decrease in thymosin(alpha 1) secreti on did not appear to be a secondary consequence of adrenocortical secr etion, and instead probably emanates from a general shift in neuroendo crine activity. Copyright (C) 1996 Published by Elsevier Science Ltd