Abstract
Adreno‐demedullated rats subjected to a moderate cold exposure showed a significant increase in urinary excretion of noradrenaline (NA) and maintained their thermal equilibrium. Adrenodemedullated rats, chronically pretreated with guanethidine, however, failed to respond with an increase in NA excretion upon exposure to 3° C and all the animals died 7 days later following a fall in urinary NA. These results suggest that the survival of cold stressed adreno‐demedullated animals is dependent upon a peripheral secretion of NA.