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.
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References in periodicals archive ?
Initial attempts at resolving coeluting analyte/interference critical pairs in plasma metanephrine analysis centered on adjustments to the chromatography.
Multiple reaction monitoring with multistage fragmentation ([MRM.sup.3]) detection enhances selectivity for LC-MS/MS analysis of plasma free metanephrines
If the tumour is diagnosed as pheochromocytoma after the operation, 24-hour urinary fractionated catecholamines and metanephrines or fractionated plasma metanephrines should be measured.
Transurethral resection of bladder tumour (TURBT) as an optional treatment method on pheochromocytoma of the urinary bladder
As yet, however, it is not established whether urine free metanephrines are superior to commonly used urine deconjugated metanephrines for diagnosis of PPGLs.
Laboratory evaluation of pheochromocytoma and paraganglioma
Measuring plasma or urine levels of metanephrines at 2-4 weeks postsurgery is recommended to determine the successful tumor removal [6].
Successful Management of Pheochromocytoma Detected in Pregnancy by Interval Adrenalectomy in a VHL Patient
Plasma free metanephrines (PMets) [6] were measured.
A 12-cm mass with no symptoms and unremarkable laboratory results
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.
Clinical case study
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.
Pheochromocytoma
Measurements of plasma methoxytyramine, normetanephrine and metanephrine as discriminators of different hereditary forms of pheochromocytoma.
Gene targeting through o-methylated catecholamine metabolite patterns
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).
Pediatric Bilateral Pheochromocytoma and Experience of Laparoscopic Cortical Sparing Adrenalectomy
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)].
Pediatric Mercury Intoxication Mimicking Pheochromocytoma
To exclude pheochromocytoma as a cause of secondary hypertension, 24-h urine metanephrine and normetanephrine levels were measured and were found to be normal.
Takayasu Arteritis Presenting as Renovascular Hypertension and Renal Failure in a Patient with Factor VII Deficiency
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.
Adrenal angiosarcoma

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