Cortical and Medullary Adrenal Activity in Surgical and Allied Conditions

AN INCREASED activity of the pituitary-adrenocortical system has been repeatedly demonstrated as part of the reaction pattern of the organism to stressful situations. The response of the adrenal medulla and the adrenergic nervous system to stress is, however, less clearly defined. The adrenal medulla is brought into increased activity by a variety of emotional stimuli, as demonstrated experimentally by Cannon and his associates (1), but the evidence for medullary hypersecretion in other situations of stress is scanty. In heavy muscular work causing fatigue, a hypersecretion of medullary hormones has been demonstrated in unanesthetized dogs (2) and in man (3). Afferent stimulation of the sciatic nerve or the brachial plexus in the anesthetized cat elicits an increased secretion of medullary hormones, especially adrenaline (4). Surgical operations and injuries no doubt represent stress-provoking factors. Clinical and experimental investigations have indicated that the pituitary-adrenocortical system is involved in the reactions of the organism evoked by surgery (5–9). We have therefore considered it of interest to obtain further information as to the reaction of the adrenal cortex and medulla in such cases. Adrenocortical activity has been estimated by determination of the blood level of 17-hydroxycorticosteroids (17-OH), and the adrenal medullary activity by the rate of adrenaline excretion in urine. The activity of the adrenergic nervous system has been estimated by determining the noradrenaline excretion in urine.