In aged rats electrostimulation of hypothalamus caused less distinct induction of the enzymes in liver tissue, kidney and spleen as compared with the adult animals. The activation of the total RNA synthesis (actinomycin D and olivomycin) eliminated the alterations in the enzymatic activities, caused by the stimulation of hypothalamus. Effect of adrenalectomy and administration of ACTH suggested that the influence of the hypothalamus stimulation on induction of the enzymes studied was realized through the system hypophysis -- adrenal cortex. In the aged animals activation of adrenal cortex was less distinct when the stimulation of hypothalamus was carried out. The alterations in hypothalamic regulation of the enzyme induction could be an important mechanism in regulation of adaptive reactions in aged organisms.