Simultaneous determination of total homocysteine, cysteine, cysteinylglycine, and glutathione in human plasma by high-performance liquid chromatography: application to studies of oxidative stress.
A sensitive, reproducible, and robust high-performance liquid chromatography (HPLC) method has been validated for simultaneously determining total concentrations of the aminothiols homocysteine, cysteine, cysteinylglycine, and glutathione in human plasma. Plasma aminothiols are reduced via incubation with tris-(2-carboxyethyl)-phosphine hydrochloride, followed by protein precipitation with trichloroacetic acid and derivatization with ammonium-7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonic acid. Separation of aminothiols and the internal standard mercaptopropionylglycine is achieved using reversed-phase HPLC conditions and fluorescence detection. Excellent linearity is observed for all analytes over their respective concentration ranges with correlation coefficients (r) > 0.99. The intra- and inter-day precision and accuracy were within +/-10%. This method utilizes an internal standard, employs phosphate buffered saline-based standards and quality controls, and demonstrates excellent plasma recovery and improved sensitivity. This assay is well suited for high-throughput quantitative determination of aminothiols in clinical studies, and is currently being used to support investigations of oxidative stress in patients with chronic kidney disease.
Nolin
Thomas D
TD
Division of Nephrology and Transplantation, Department of Medicine, Maine Medical Center, 22 Bramhall Street, Portland, ME 04102, USA. nolint@mmc.org
McMenamin
M Elizabeth
ME
Himmelfarb
Jonathan
J
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003545:Cysteine / Q000097:blood*; D004151:Dipeptides / Q000097:blood*; D005978:Glutathione / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D018384:Oxidative Stress; D012015:Reference Standards; D015203:Reproducibility of Results
D004151:Dipeptides; D006710:Homocysteine; C028505:cysteinylglycine; D005978:Glutathione; D003545:Cysteine