The CBA line adult mice were randomized into four groups: 1 - Control; 2 - Chronical irradiation; 3 - Uranyl nitrate treatment; 4 - Combined exposure to radiation and nitrate. There is a significant increase (p < 0.01, p < 0.001) in absolute and relative weights of suprarenal glands in 3rd and 4 experimental groups (30-day irradiation, dose 1.6 cGy and Uranyl nitrate liquid solution with activity of 238U - 25 Bq/L). The animals from 2nd group had a significant decrease (p < 0.001) in the suprarenal cortex size due to the decreasing in the glomerular and fasciculate zones width, whereas the decreasing in the suprarenal gland cortex size in animals from 3rd and 4 groups was due to all three zones (p < 0.01). The significant increasing (p < 0.05) in the adrenal medulla diameter was observed in animals from 3rd and 4 groups.