Medicine Medical SuppliesDetection Kit
Metanephrine (M) and normetanephrine (NM) are O-methylated metabolites of the catecholamines epinephrine (E) and norepinephrine (NE) respectively. Both of these can be further metabolised to vanillylmandelic acid. The basic common structure present in both of these molecules is a methylated catechol ring (3-methoxy 4-hydroxy phenyl) in conjunction with an ethylamine group. Metanephrine is found to possess the higher molecular weight of 197 g/mol which is in contrast to NM that is 183 g/mol. The reason for the difference in molecular weight is due to the presence on a methylated amino group.
These metanephrines have been useful in providing markers of the extraneuronal metabolism of the parent catecholamines. In particular for clinical medicine, they have been vital diagnostic tools for identifying patients that maybe suspected of containing tumors of chromaffin (for example pheochromocytoma and paraganglioma). Both of the metabolites can be measured in plasma and urine, where the determination of conjugated metanephrines in urine has been a long-standing and well-established procedure. Recent, emergence of a reliable assay methods for plasma-free metanephrines has fostered a more extensive assessment of the metabolism of catecholamines.