EFFECTS OF PREPUBERTAL STRESS ON SUBSEQUENT ACTH RESPONSE TO NOVEL STRESS AND CRH IN MALE VS FEMALE RATS

The effects of long-term chronic stress during prepubertal periods of growth and development on an organism's ability to release ACTH during future episodes of an acute novel stress and in response to exogenous CRH were examined. Following a 6-week stress period, in which prepube rtal male and female WKY rats were subjected to three different and ra ndomly given stress paradigms (heat, noise and immobilization) at vari ous times of the day (in order to prevent adaptation to stress), chron ically stressed male rats were far less able to respond to CRH plus a novel ether stress than were their male controls or their female count erparts. Although baseline ACTH levels were similar in both male and f emale control and experimental rats, when subjected to a subsequent ac ute ether stress, the differences in ACTH response between controls an d experimentals as well as between males and females were significant. ACTH response to stressors was significantly blunted in both male and female experimental rats compared to their controls, but the male res ponse was significantly lower than that of the females. These results suggest that prepubertal chronic stress may permanently alter an organ ism's ability to release ACTH, even when subjected to a novel and trau matic ether stress, and that males may be much more susceptible than f emales to prepubertal stress. Long-term stress, therefore, if experien ced during critical developmental periods such as preadolescence, can permanently damage the stress response mechanism and cause other, more serious physiological disorders.