[Morpho-functional alterations of the adrenal cortex in rats with active and passive strategy of adaptive behavior]

In rats with the active (KHA strain) and passive (KLA strain) coping strategies, a post-stress depression develops respectfully on the 1st or 10th day after the inescapable stress. The present study revealed an increase of adrenal weight and blood corticosterone levels on a day following the inescapable stress, as well as marked fluctuations of blood glucose in one and five days post-stress in KHA rats. By the 10th day, these indices returned their basal levels. In contrast, the stress reactivity of KLA rats was lower in all terms and their corticosterone levels remained reduced on the 10th day after stress. In KLA rats, the fasciculate zone was reduced but reticulated zone grew in Ith day following the stress, while in KHA rats the inescapable stress resulted in growth fasciculate zone and concomitant reduction of reticulate zone, both evident on the 10th post-stress day. The data indicate that the development of post-stress depression in KLA rats is probably associated with exhaustion of adrenocortical function.