Circulating dopamine-beta-hydroxylase (DbetaH) and catecholamines in a paediatric phaeochromocytoma

1. Circulating catecholamines and dopamine-beta-hydroxylase (DbetaH) 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 DbetaH activity in the latter was only slightly elevated. 3. Circulating catecholamines fluctated greatly while DbetaH activity decreased gradually during the removal of the tumours. 4. Post-operatively, circulating catecholamines declined to normal values while DbetaH activity returned to pre-operative levels. 5. It is concluded that these tumours released circulating catecholamines independent of an exocytotic secretion of DbetaH and that the circulating DbetaH reflected the activity of the sympathetic nervous system.