Catecholamines, Fractionated, Random Urine - The three catecholamines (norepinephrine, epinephrine, and dopamine) are the principal secretory products of neural tissue. Clinically, the measurement of circulating catecholamines is valuable in the diagnosis of catecholamine secreting tumors associated chiefly with hypertension (pheochromocytomas, neuroblastomas, and gangliomas) and with the evaluation of orthostatic hypotension.