Enzyme and acid deconjugation of plasma sulfated metanephrines.

Details

Serval ID
serval:BIB_B6C7D6A06DEF
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Enzyme and acid deconjugation of plasma sulfated metanephrines.
Journal
Clinica Chimica Acta; International Journal of Clinical Chemistry
Author(s)
Glauser M., Metrailler M., Gerber-Lemaire S., Centeno C., Seghezzi C., Dunand M., Abid K., Herren A., Grouzmann E.
ISSN
1873-3492 (Electronic)
ISSN-L
0009-8981
Publication state
Published
Issued date
2014
Peer-reviewed
Oui
Volume
430
Pages
125-128
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov'tPublication Status: ppublish
Abstract
BACKGROUND: Total (i.e. free+sulfated) metanephrines in plasma is a biomarker for the diagnosis of pheochromocytoma/paraganglioma. Sulfated metanephrines must be completely deconjugated by perchloric acid hydrolysis or sulfatase treatment prior to analytical measurement to enable quantification by current techniques. In this report, we compare the yield and efficiency of both methods.
METHODS: The deconjugation rate of synthetic sulfated metanephrines (normetanephrine (S-NMN), metanephrine (S-MN) and methoxytyramine (S-MT)) spiked in charcoal-stripped plasma was determined by boiling perchloric acid and compared to sulfatase treatment. Total plasma metanephrines (MN, NMN and MT) were also determined in patient samples by both methods.
RESULTS: The complete deconjugation of sulfated metanephrines is achieved after 30 min incubation with 0.1M boiling perchloric acid or upon sulfatase treatment. Ten minutes of acid hydrolysis (gold-standard) leads to a 30% underestimation of metanephrine concentrations. The enzyme hydrolysis is time and amount of sulfatase dependent. The rate of hydrolysis is analyte-dependent (MT>NMN>MN), although it must contain at least 0.8 U/ml of sample. The Deming regression curves comparing acid versus enzyme hydrolysis on patient samples assessed that both methods gave similar unbiased concentrations.
CONCLUSION: Enzyme and acid treatments are equivalent and efficient for removing sulfate from metanephrines as long as the optimal protocol is used for each method. However, the gold standard method for acid hydrolysis at 10 min established more than 20 years ago was not satisfactory regarding the hydrolysis of metanephrines in plasma.
Keywords
Humans, Hydrolysis/drug effects, Metanephrine/blood, Metanephrine/chemistry, Perchlorates/chemistry, Perchlorates/pharmacology, Sulfatases/metabolism
Pubmed
Web of science
Create date
18/10/2016 17:02
Last modification date
20/08/2019 16:25
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