Stressor controllability and the pituitary-adrenal system.

Stressor controllability can alter both behavior and pituitary-adrenal (PAD) activity. Potential mediation of these behavioral effects by differential PAD output requires that the precise conditions that lead to differential behavioral consequences also produce differential PAD activity. In 2 experiments, plasma adrenocorticotropic hormone (ACTH) and corticosterone levels were measured in 152 male Holtzman rats at various times following escapable and yoked inescapable electric shock conditions known to produce differential behavioral outcomes. The escapable and inescapable shock procedures did not produce a detectable differential effect. Both shock conditions produced equivalent elevation of ACTH and corticosterone. Neither decay rates nor the ACTH and corticosterone response to shock reexposure differed among shocked groups. Implications for alterations in immune function and for conceptions of the relation between stress and PAD activity are discussed. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)