Urinary Excretion of Catecholamines and Their Metabolites in Normotensive and Hypertensive Subjects

The urinary excretion of catecholamines and their metabolites was determined and the ratio among their values was calculated in normal and hypertensive subjects. No significant difference in the excretion of methoxycatecholamines and vanillylmandelic acid was found between normal subjects and patients with essential hypertension. The ratio of catecholamines/methoxycatecholamines/vanillylmandelic acid proved to be almost the same between them. From these results, we discussed the problem of the pathogenesis of essential hypertension and could not support the hypothesis that an overactivity of sympatho-adrenal system or an abnormality in the enzymatic system of catecholamine inactivation is present in essential hypertension. In addition, we discussed the value of determination of catecholamines and their metabolites in making the diagnosis of pheochromocytoma.