Effects of immobilization stress and hypophysectomy on the uptake of [H-3] 2-deoxy-D-glucose (2DG) in the adrenal medulla of the mouse was examined by autoradiography. Radioactivity due to [H-3]2DG in both adrenaline-storing and noradrenaline-storing cells was markedly increased by acute immobilization stress. Under immobilization stress, adrenaline-storing cells incorporated more 2DG than noradrenaline-storing cells. Adrenal denervation did not change the uptake of 2DG either in control or in stressed adrenal medulla. The uptake of [H-3]2DG was also increased by hypophysectomy. Since withdrawal of cortical steroid hormones enhanced the uptake of 2DG and the adrenal denervation did not change the uptake, it is suggested that certain substances, such as bradykinin or histamine, which are released on immobilization stress from certain tissues other than sympathetic nerve endings in the medulla, enhanced the uptake of [H-3]2DG. This phenomenon occurs mainly in adrenaline-storing cells.