Maturation of the Sympatho‐Adrenal System and Clinical Values of the Determination of Urinary Catecholamine Excretion

Sympatho-adrenal system function was assessed in various age groups of normal subjects and in infants with some abnormal conditions, by assays of daily urinary catecholamine excretion. The urinary catecholamine excretion was prone to increase postnatally with time. The group of children aged 1 to 5 years exhibited a significantly greater urinary catecholamine excretion than the group of newborn infants. No significant difference concerning urinary catecholamine excretion was observed among three age groups, 1–5, 6–10 and 10–20 years of age. This finding is related to rapid growth and maturation of the sympatho-adrenal system in early life with increased catecholamine excretion. Moreover, the urinary catecholamine excretion was remarkably increased at symptomatic exacerbation and declined to a normal level with alleviation of symptoms in a case of respiratory distress syndrome. The present communication is the first to demonstrate the usefulness of urinary catecholamine determination in newborn infants.