[The effect of stress on the anxiety level in female white rats at different stages of the estrous cycle].

Locomotor activity in the elevated plus-maze was studied in female white rats following chronic stress induction (measuring pain threshold in the course of 15-20 days). Anxiety and plasma corticosterone levels were determined. In control experiments in intact rats anxiety was lower and locomotor activity was higher in proestrus than in diestrus. There were no differences in anxiety and locomotor activity between diestrus and proestrus in rats exposed to chronic stress. In intact rats plasma corticosterone levels were the same in proestrus and diestrus. Following chronic stress plasma corticosterone level was significantly higher in proestrus than in diestrus.