Thii©dIL Thin-Layer Chromatographic Method for Urinary 4-Hydroxy-3-Methoxymandelic Acid (VaniImandelic Acid)

introduction Clinical interest in the physiologically active pressor amines-epinephrine, norepinephrine and their me-tabolites-has been enhanced by the finding that greatly increased amounts are excreted in the urine of patients with neural and adrenal medullary tumors (1-4). Symptomatic of the development of these neu-roblastomas and pheochromocytomas is the onset of intermittent hypertension. More than 15 % of the pop-ulation has hypertension of one etiology or another; relatively few of these cases are attributable to neural or adrenal tumors. A simple, fast, and reliablescreening method is needed to rule out such causes of hyperten-sion before rational therapy can be started. A series of analytical procedures have appeared in th