Plasma normetanephrine measurements for detection of pheochromocytoma in patients with hypertension.
We describe a simple and specific radioenzymatic assay for measurement of total plasma normetanephrine (NMN), which is an extension of a previously developed procedure for measuring of urinary NMN. Plasma NMN is deconjugated by acid hydrolysis at pH 1.0 and boiled for 20 min. The assay is based on the conversion of NMN to its N-methylated, tritiated derivative metanephrine (3H-MN), utilizing phenylethanolamine N-methyltransferase and S-adenosyl-[3H]methionine. The assay is rapid, sensitive and results can be obtained in less than 4 h. Many antihypertensive drugs tested did not interfere with the assay. This assay could be used for detection of pheochromocytomas in patients with hypertension.
D000310:Adrenal Gland Neoplasms / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000150:complications*; D009647:Normetanephrine / Q000097:blood*; D010673:Pheochromocytoma / Q000097:blood / Q000150:complications / Q000175:diagnosis*
D009647:Normetanephrine