Abstract
This paper describes the attempts that were made to obtain a replacement of adrenaline and noradrenaline in the adrenal gland of the atropinized cat, subsequent to the depletion of the gland by repeated intravenous doses of acetylcholine. In the anaesthetized animal, there was no replacement of adrenal amines within 15 hours of the depletion. The further loss of amine that occurred during this time was prevented by the de nervation of the gland. If the animal was allowed to recover from the anaesthetic there was some replacement of amines within 2 to 3 days, provided that the condition of the animal was satisfactory. By 6 to 7 days the total amine content had returned to its initial level, but there was now an alteration in the relative proportions of the two amines. Although the adrenaline was still well below the resting level, the noradrenaline was several times its initial value. By one month, the noradrenaline had decreased and the adrenaline had increased to their initial amounts and proportions. Thus this work gives evidence for the formation of adrenaline from noradrenaline.