title: [Measurement of platelet catecholamine content for the diagnosis of pheochromocytoma with intermittent hypertension].
abstract: We have compared platelet and plasma catecholamines (radioenzymatic assay with catechol-O-methyl transferase) and urinary metanephrines (high performance liquid chromatography) in 16 patients with phaeochromocytoma, 12 essential hypertensives, and 15 normotensive volunteers. Hypertensive patients with or without phaeochromocytoma had labile or paroxysmal hypertension with normal or borderline blood pressures between paroxysms. Catecholamine concentrations in platelets and plasma did not differ in essential hypertensives and controls, but were higher in patients with phaeochromocytoma than in subjects without tumour, with values overlapping between groups. Metanephrine excretion was markedly higher in phaeochromocytoma than in essential hypertension, with no intergroup overlap. Platelet adrenaline plus noradrenaline content was highly correlated to urinary metanephrines (r' = 0.830, n = 28 p less than 0.01). Using as a cut-off point the highest values measured in essential hypertensives, the sensitivity of each measurement was 1.00 for metanephrines, 0.87 for platelet catecholamines and 0.50 or less for plasma catecholamines. Measurement of platelet catecholamine content is a sensitive test and an appropriate alternative to metanephrine measurement in the difficult cases of suspected phaeochromocytoma with intermittent hypertension.
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000097:blood / Q000175:diagnosis*; D000328:Adult; D001792:Blood Platelets / Q000032:analysis*; D002395:Catecholamines / Q000032:analysis*; D006801:Humans; D006973:Hypertension / Q000097:blood*; D008875:Middle Aged; D010673:Pheochromocytoma / Q000097:blood / Q000175:diagnosis*
chemical_list: D002395:Catecholamines
vernacular_title: Mesure du contenu plaquettaire en catécholamines pour le diagnostic des phéochromocytomes avec hypertension intermittente.