The Effect of Cold Exposure on the Catecholamine Excretion of Adrenalectomized Rats Treated with Reserpine

Adrenalectomizad rats subjected to moderate cold exposure showed a significant increase in noradrenaline excretion in urine. Adrenalectomized rats, treated with reserpine. howevar, failed to respond with an increase in the noradrenaline excretion during cold stress. A fall in the noradrenaline excretion of the reser‐pinized animals was usually followed by death. These results suggest that reserpine treatment inhibits the synthesis of noradrenaline in vivo and that the survival of moderately cold stressed adrenalectomized animals is related to the secretion of noradrenaline.