Adrenal and hypothalamic structure has been studied in mice at functional inhibition of the sympathetic region of the vegetative nerve system by means of antibodies against the nerve growth factor. Routine histological, histochemical, morphometric, electron microscopic and radioautographic methods have been applied. In the experiment the hypothalamic region is in the state of a continuous functional stress which is evident from enlargement of neurons and their nuclei in the macrocellular neurosecretory nuclei of the hypothalamus. The method of radioautography proves increasing activity in synthetic processes taking place in supraoptic, paraventricular and ventromedial nuclei of the hypothalamus and in the medial habenular nucleus of the epithalamus. In 30-day-old mice certain structural changes have been revealed in the adrenals demonstrating an increasing activity in their cortex: blood vessels are dilated, cholesterine, lipid and ascorbic acid granules are not evenly distributed, enzymatic activity in cytoplasm of adrenocorticocytes is increased. Ultramicroscopic destructive and regenerative alterations have no definite zonal specificity, nevertheless they are more pronounced in the fascicular zone. Radioautographic and morphometric investigations demonstrate an increasing functional activity in glomerular and fascicular adrenal zones. Taking into account morphologic demonstration of functional stress in hypophysial adenocytes in the same animals (Molostov O. K., 1974), it is possible to conclude that lesions in the sympathetic system center result in adaptive reaction of the hypothalamo-hypophysial system which, in its turn, produces reactions in the adrenals and in the vascular complex. This interconnection is accompanied by the reaction depending on breaking off direct sympathetic effects in the adrenals and vessels.