Medicine Medical SuppliesDetection Kit
Metanephrine (M) and normetanephrine (NM) both contain a common structure of a methylated catechol ring (3-methoxy 4-hydroxy phenyl) in conjunction with an ethylamine group. Both of these are also O-methylated metabolites of the catecholamines epinephrine (E) and norepinephrine (NE) respectively. However, metanephrine is known to have a higher molecular weight of approx. 197 g/mol whereas NM is 183 g/mol. The only reason for this difference is because it contains a methylated amino group.
For clinical medicine metanephrine and normetanephrine have played essential roles in helping to identify individuals that could be possible suspects for possessing tumors of chromaffin (e.g. pheochromocytoma and paraganglioma). These metanephrines are also helpful as markers for extraneuronal metabolism of the parent catecholamines.
Both of the metabolites are routinely analysed in either plasma or urine samples, where it is only recently there has been an emergence of accurate and reliable procedure for determining plasma free metanephrines. Whereas the measurement of urine conjugated metanephrines have been used for quite a long time now and also is a very well established procedure.