[Metabolism of catecholamines in the clinical biochemistry of hypertension].

The object of this study was to review the state of methods of investigating the mmetabolism of catecholamines in the biochemical study of hypertension. A comparison between blood and urinary parameters would seem to show urinary metanephrine levels to be the most discriminating biochemical indicator of pheochromocytoma: this parameter is particularly valuable when pheochromocytoma is associated with normal blood pressure, a situation in which the circulating catecholamine levels are usually unchanged. Three recent aspects of this diagnosis, the development of which may provide new information, are discussed: differentiation between free and conjugated catecholamines, evaluation of platelet amines, the clonidine test. The study of the métabolism of catecholamines in non-tumoral hypertension is also considered but the problems in performing and interpreting these tests are much more difficult.