CIRCULATING DOPAMINE-β-HYDROXYLASE (DβH) AND CATECHOLAMINES IN A PAEDIATRIC PHAEOCHROMOCYTOMA

SUMMARY 1. Circulating catecholamines and dopamine‐β‐hydroxylase (DPH) have been studied in a child with bilateral phaeochromocytoma. 2. Venous catheterization showed a great increase in catecholamine efflux from the left adrenal vein while DPH activity in the latter was only slightly elevated. 3. Circulating catecholamines fluctuated greatly while DBH activity decreased gradually during the removal of the tumours. 4. Post‐operatively, circulating catecholamines declined to normal values while DβH activity returned to pre‐operative levels. 5. It is concluded that these tumours released circulating catecholamines independent of an exocytotic secretion of DβH and that the circulating DβH reflected the activity of the sympathetic nervous system.