Vasoactive hormones in familial pheochromocytoma with predominant norepinephrine secretion.

A family was investigated with an increased occurrence of pheochromocytoma. Three males out of 7 family members showed biochemical and morphological evidence of catecholamine-secreting tumor. Plasma concentrations of norepinephrine, aldosterone, arginine vasopressin and renin activity, as well as urinary excretion of norepinephrine, were enhanced in all the 3 patients. The plasma level of atrial natriuretic peptide decreased. After surgical removal of the tumor the hormonal alterations tended to be normalized; however, plasma concentration of norepinephrine remained above normal. The elevated plasma norepinephrine was postoperatively accompanied by slightly increased urinary norepinephrine excretion in 1 patient without any detectable tumor. The severity of the disease was most pronounced in the youngest patient, while in the oldest one a 'silent' pheochromocytoma was found. The occurrence of familial pheochromocytoma in successive generations may suggest an autosomal-dominant inheritance.