We studied the impact of prolonged immobilization on adaptation of the cardiovascular system in 100-day-old rats, in particular, the possibility of stress evaluation via extrapolation of expression of endothelial dysfunction induced experimentally. The animals were examined by ultrasonic scanning within 10 days of immobilization stress. According to the changes in leukogram, it was found that the first stage of stress (anxiety) was short or unexpressed, the second stage (resistance) was observed from the 2nd to the 7th day, and the stage of exhaustion developed on the 8th day. As a result of analysis of variance, hemodynamics revealed some features of the restructuring of the reaction vessel wall, depending on the stage of the stress. The stage of resistance was characterized by intraluminal diameter of the abdominal aorta at the level of 1.5 ± 0.1 mm, the thickness of the structure and the intima-media at 0.28 ± 0.04 mm and endothelial sensitivity to acetylcholine. Under stress, the signs of endothelial dysfunction were detected: the changes in the structure of the intima-media and the lack of response of the endothelium to acetylcholine, and the characteristics of abdominal aortic wall remodeling: thickening of the intima-media complex to 0,35 ± 0,06 mm and an increased intraluminal diameter to 1.9 ± 0.1 mm. The changes in speed of hemodynamic parameters determined a decrease in the mean blood flow velocity and an increase n the stiffness of the abdominal aortic wall.