Voluntary physical activity prevents stress-induced behavioral depression and anti-KLH antibody suppression

The current study addressed whether physical activity can buffer stress-ind uced "behavioral depression" and immunosuppression. Adult, male Sprague-Daw ley rats were housed with either a mobile (physically active) or immobile ( sedentary) running wheel and exposed to either stress (inescapable tail sho ck) or no stress (home cage control). Voluntary wheel running began 4 wk be fore stressor exposure. Immediately before stress, all rats were administer ed an intraperitoneal injection of keyhole limpet hemocyanin (KLH; 200 mug) , and anti-KLH Ig was measured weekly for 4 wk using ELISA. Prior physical activity reduced the stress-induced behavioral depression and prevented the stress-induced suppression of anti-KLH IgM and IgG(2a) antibodies. Anti-KL H IgG(1) was stress insensitive. These data suggest that physical activity can buffer the negative impact of stress on behavior and acquired immune fu nction.