BACKGROUND Measurements of plasma free metanephrines (normetanephrine and metanephrine) provide a useful test for diagnosis of pheochromocytoma and may provide other information about the nature of these tumors. METHODS We examined relationships of tumor size, location, and catecholamine content with plasma and urinary metanephrines or catecholamines in 275 patients with pheochromocytoma. We ...

The optimal evaluation of patients suspected of having a pheochromocytoma remains controversial. The availability of large numbers of hormone assays and the need to exclude with certainty a potentially lethal disorder with an unpredictable course have led to various approaches to biochemical testing. The quantification of the urinary excretion rate of catecholamine and catecholamine metabolites...

The optimal evaluation of patients suspected of having a pheochromocytoma remains controversial. The availability of large numbers of hormone assays and the need to exclude with certainty a potentially lethal disorder with an unpredictable course have led to various approaches to biochemical testing. The quantification of the urinary excretion rate of catecholamine and catecholamine metabolites...

In this method for measuring metanephrine and normetanephrine in urine, they are freed from their conjugates by hydrolysis in acid, neutralized, and isolated on a cation-exchange resin. Both metanephrines are co-eluted with ammoniacal methanol and the eluate is concentrated 10-fold with respect to the original urine volume by evaporation and reconstitution. The recovered metanephrines ae separa...

In this relatively simple procedure for extracting metanephrines from urine, after an internal standard (4-hydroxy-3-methoxybenzylamine in 1 mmol/L HCl) is added, the sample is hydrolyzed in a boiling water bath, then treated with ammonia and alumina. Excess ammonia is removed under reduced pressure and the sample is applied to a 1-mL Bond Elut SCX column, which is washed, and metanephrines and...

Quantitative determination of catecholamines and their O-methyl metabolites plays an important role in the diagnosis of pheochromocytoma (PHEO) – adrenal medulla tumour. This kind of tumour synthesizes, stocks, metabolizes and mostly secretes catecholamines. For this reason it is possible to use elevated concentrations of catecholamines and their metabolic products from plasma and urine as diag...

Phaeochromocytoma and extra-adrenal paragangliomas are rare catecholamine-producing tumours which, if not timely and properly diagnosed, may result in catastrophic consequences. 1 Definite exclusion or confirmation of the tumour is of utmost clinical importance. For this purpose several biochemical tests are available with those measuring metanephrines as the most accurate ones. Even at a very ...

Fifteen patients with hypertension due to phaeochromocytoma and 35 controls with essential hypertension were studied to assess the diagnostic value of urinary and plasma biochemical determinations in phaeochromocytoma. In every case of phaeochromocytoma the urinary concentration of vanillylmandelate, metanephrines, or adrenaline plus noradrenaline was diagnostic of the disease irrespective of w...

tems calibrators for metanephrines. The increase in sources of calibrators did not cause a decrease in the accuracy of the results during external quality control program in the 2004– 2006 period. The observed differences in published reference values for urinary metanephrines are not mainly because of analytical reasons but most probably are due to differences in the characteristics of referen...

During the development of an assay for the metanephrines (m 0 -methylepinephrine and m 0 -methylnorepinephrine) in human urine (I), another compound was detected which had similar chemical and chromatographic properties. Like the metanephrines, it was adsorbed onto a weak cation exchange resin, and upon treatment with periodate it yielded a product which absorbed ultraviolet light. The identifi...