metanephrine


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Related to metanephrine: pheochromocytoma, Catecholamines

metanephrine

 [met″ah-nef´rin]
a urinary metabolite of epinephrine.

met·a·neph·rine

(met-ă-nef'rin),
A catabolite of epinephrine found in the serum, urine and in some tissues, resulting from the action of catechol-O-methyltransferase on epinephrine; has no sympathomimetic actions; 3-O-methylepinephrine.

metanephrine

Any exogenous or endogenous catecholamine metabolite excreted in the urine (normal adults, 0.03–0.69 mmol/mol creatinine). Metanephrines are elevated in neuroblastoma, pheochomocytoma, metastases, stress and sepsis.
 
False positive elevation
High dietary intake of bananas, or therapy with chlopromazine, corticosteroids, l-dopa, dopamine, guanethidine, hydralazine, imipramine, nalidixic acids, phenobarbital, phenylephrine, or tetracycline.
 
False negative reduction
Clonidine, guanethidine, propranolol, reserpine.
 
Ref range
24–288 µg/24 hours; US, 0.05–1.2 mg/24 hours.
 
Specimen
24-hour urine.
 
Method
HPLC.

metanephrine

Methoxyepinephrine Lab medicine Any exogenous or endogenous catecholamine metabolite excreted in the urine; metnephrines ↑ in neuroblastoma, pheochomocytoma, metastases, stress, sepsis

met·a·neph·rine

(met'ă-nef'rin)
A metabolite of epinephrine, excreted in the urine and found in some tissues.

met·a·neph·rine

(met'ă-nef'rin)
A catabolite of epinephrine found in the serum, urine, and some tissue types, due to action of catechol-O-methyltransferase on epinephrine.
References in periodicals archive ?
Initial attempts at resolving coeluting analyte/interference critical pairs in plasma metanephrine analysis centered on adjustments to the chromatography.
If the tumour is diagnosed as pheochromocytoma after the operation, 24-hour urinary fractionated catecholamines and metanephrines or fractionated plasma metanephrines should be measured.
As yet, however, it is not established whether urine free metanephrines are superior to commonly used urine deconjugated metanephrines for diagnosis of PPGLs.
Measuring plasma or urine levels of metanephrines at 2-4 weeks postsurgery is recommended to determine the successful tumor removal [6].
Plasma free metanephrines (PMets) [6] were measured.
As outlined in the report, testing for pheochromocytoma should include measurements of plasma or urinary metanephrines, metabolites produced continually within tumor cells from catecholamines leaking from storage vesicles.
Graeme Eisenhofer: To date there have been 4 studies directly comparing the diagnostic performance of plasma free vs urinary fractionated metanephrines, all consistently indicating higher diagnostic sensitivity and specificity of the plasma over the urine test.
Measurements of plasma methoxytyramine, normetanephrine and metanephrine as discriminators of different hereditary forms of pheochromocytoma.
Measurement of plasma free metanephrine and normetanephrine or 24-h urinary fractionated metanephrines are considered to be the most accurate biochemical tests for pheochromocytoma (4).
Plasma metanephrine levels were normal-to-mildly elevated [metanephrine 0.30 (reference value: 0-0.46 nmol/L); normetanephrine 1.06 (0-0.98 nmol/L); epinephrine 0.73 (0-0.46 nmol/L); norepinephrine 4.45 (0-2.48 nmol/L); domapine <0.2 (0-0.55 nmol/L)].
To exclude pheochromocytoma as a cause of secondary hypertension, 24-h urine metanephrine and normetanephrine levels were measured and were found to be normal.
Preoperative LDH measurement was 422 U/L, VMA was 1.93 mg/day, normetanephrine was 255.5 [micro]g/24 h, metanephrine was 60.9 [micro]g/24 h, and cortisone was 2.03 [micro]g/dL.