title: Determination of N tau-methylhistamine in plasma and urine by isotope dilution mass fragmentography.
abstract: The determination in N tau-methylhistamine by gas chromatography-mass spectrometry is described using bis-heptafluorobutyryl derivatives and deuterium labelled N tau-methylhistamine as internal standard. A description of the synthesis of the internal standard, N tau-trideuteromethylhistamine, is given. Normal concentrations for plasma were 1.4 +/- 0.4 microgram/l (mean +/- 1 S.D., n = 10). The normal values for urine ranged from 60 to 280 microgram/24 h (n = 20). Five asthmatic patients showed above-normal plasma concentrations.
mesh_terms: D001249:Asthma / Q000097:blood; D003903:Deuterium; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006639:Histidine / Q000031:analogs & derivatives*; D006801:Humans; D007553:Isotope Labeling; D008762:Methylhistidines / Q000032:analysis* / Q000097:blood / Q000652:urine; D012016:Reference Values
chemical_list: D008762:Methylhistidines; C028120:1-methylhistidine; D006639:Histidine; D003903:Deuterium