Medicine Medical SuppliesDetection Kit
Normetanephrine is a catecholamine metabolite of norepinephrine and it is formed through the action of catechol-O-methyl transferase on norepinephrine. Cells that are found to be derived from neuroendocrine tumors (for example pheochromcytoma) can produce catecholamines that are secreted episodically using vesicles into the blood stream. However, there are a small portion of the catecholamines which can be metabolised inside the cells into their corresponding catecholamines metabolites and these are namely metanephrine, normetanephrine and 3-methoxytyramine. These catecholamines can be continuously secreted at low levels into the blood stream.
In clinical medicine, these catecholamines have been useful in providing diagnostic tools for identifying patients that are suspected of having a tumor of chromaffin cells such as pheochromocytoma and paraganglioma. These metabolites (normetanephrine and metanephrine) can be measured in plasma or urine samples. The determination of conjugated normetanephrine in urine is a well-established and long-standing technique. Current literature is indicating that the analysis of urine normetanephrine is an accurate biochemical marker for identifying patients suspected of pheochromocytoma. The current guidelines recommend the use of either plasma free normetanephrines or urinary fractionated normetanephrines for the initial biochemical phase.