Noradrenaline injected into cerebral lateral ventricles was found to change the temperature homeostasis in white rats. The fall of rectal temperature, the rise of brown adipose tissue temperature and oxygen consumption occurred within 25-30 min after the injection. Preliminary adaptation to cold increased the effect of noradrenaline. The beta-adrenergic blockade of cerebral structures by propranolol altered the noradrenaline effect: both the rise of brown adipose tissue temperature and the oxygen consumption increase do not occur. This effect is more obvious in cold-adapted animals. The adaptation to cold seems to increase the sensitivity of central adrenergic structures to noradrenaline, central beta-adrenoreceptors being mainly responsible for the effect of noradrenaline (the rise of brown adipose tissue temperature and the oxygen consumption increase) on the thermoregulation.