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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
21
|
| pubmed:dateCreated |
1982-12-18
|
| pubmed:abstractText |
N tau-Methylimidazoleacetic acid, the histamine metabolite, and its isomer, N pi-methylimidazoleacetic acid, were demonstrated and measured in rat brain and in human cerebrospinal fluid, urine, and plasma by a gas chromatographic-mass spectrometric method that is simple and specific with a detection limit of about 7 pmol (i.e. 1 ng). The acids were separated in biological samples by ion exchange chromatography, derivatized as n-butyl esters with boron trifluoride-butanol, and extracted with chloroform. Complete chemical ionization mass spectra and mass ion abundance ratios established the identity of N tau - and N pi - methylimidazoleacetic acids in the biological extracts and of imidazoleacetic acid in urine, but not in cerebrospinal fluid, plasma, and brain. The methylimidazoleacetic acids as n-butyl esters were quantified by electron impact selected ion monitoring of m/e 95 esters at different retention times. 3-Pyridylacetic acid was used as an internal standard and monitored at m/e 93. The levels of N tau-methylimidazoleacetic acid and N pi-methylimidazoleacetic acid were, respectively (picomoles/g or picomoles/ml +/- S.E.), for brain, 373, 19 +/- 13.08 and 110.33 +/- 12.44; for cerebrospinal fluid, 22.77 +/- 2.15 and 80.76 +/- 18.92; and for plasma, 84.57 +/- 13.64 and 73.64 +/- 14.50. In urine, the respective levels were 20.75 +/- 1.30 and 73.02 +/- 38.22 nmol/mg of creatinine. The origin of N pi-methylimidazoleacetic acid is not certain.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Nov
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
10
|
| pubmed:volume |
257
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
12815-9
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading | |
| pubmed:year |
1982
|
| pubmed:articleTitle |
Presence and measurement of methylimidazoleacetic acids in brain and body fluids.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|