title: Determination of agmatine in brain and plasma using high-performance liquid chromatography with fluorescence detection.
abstract: Decarboxylated arginine, agmatine, is a neurotransmitter candidate for imidazoline receptors. A method is described to measure agmatine in rat brain and human plasma by isocratic high-performance liquid chromatography (HPLC) with fluorescence detection and o-phthalaldehyde derivatization. Quantitation is based on the method of additions of internal agmatine spikes. This assay has sensitivity in the low picomole range and a detection limit of 100 fmol. The correlation coefficient for the agmatine standard curve was 0.999+/-0.001 S.D., and intra- and inter-assay C.V.s were less than 8%. The accuracy of our isocratic method compared favorably with a gradient HPLC protocol, originally developed for bacterial agmatine, which we modified for use with tissues. Agmatine concentrations in rat brain were proportioned similarly to the regional distribution of imidazoline-1 receptors. These methods can be used as reliable research tools in various biological samples.
authors.affiliation: Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson 39216, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Feng
authors.forename: A E
authors.initials: AE
authors.lastname: Halaris
authors.forename: J E
authors.initials: JE
authors.lastname: Piletz
mesh_terms: D000328:Adult; D000376:Agmatine / Q000032:analysis / Q000097:blood*; D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D008875:Middle Aged; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D009764:o-Phthalaldehyde
chemical_list: D007202:Indicators and Reagents; D009764:o-Phthalaldehyde; D000376:Agmatine