title: Simultaneous quantitative determination of microcystin-LR and its glutathione metabolites in rat liver by liquid chromatography-tandem mass spectrometry.
abstract: The roles of glutathione (GSH) and cysteine (Cys) in the detoxification of Microcystin-LR (MC-LR) have recently become a popular area of research. However, lacking analysis methods for MC-LR-GSH and MC-LR-Cys (two main GSH pathway metabolites) in mammals, elucidation of the detoxification mechanism and metabolic pathway of MC-LR in mammals is difficult. In this study, a novel method for the simultaneous quantitative analysis of MC-LR, MC-LR-GSH and MC-LR-Cys in rat liver was developed and validated. The analytes were simultaneously extracted from rat liver using 3M sodium chloride solution containing 0.01M EDTA-Na2-5% acetic acid, followed by solid-phase extraction (SPE) on Oasis HLB and silica cartridges and determination by liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS/MS). Under the optimized pretreatment conditions and instrument parameters, good recoveries of MC-LR, MC-LR-GSH and MC-LR-Cys were obtained at three concentrations (0.2, 1.0 and 2.5 μg g(-1) dry weight (DW)) with values ranging from 97.7 ± 4.2 to 98.7 ± 5.1%, 70.1 ± 4.8 to 71.1 ± 4.1% and 79.8 ± 3.5 to 81.4 ± 4.0%, respectively. The relative standard deviations (RSDs) of these compounds at 0.2, 1.0 and 2.5 μg g(-1) DW were between 4.3% and 6.9%. The limits of detection (LODs) were 0.005, 0.007 and 0.006 μg g(-1) DW and the limits of quantification (LOQs) were 0.017, 0.023 and 0.020 μg g(-1) DW for MC-LR, MC-LR-GSH and MC-LR-Cys, respectively. Furthermore, this method was successfully applied to both time- and dosage-effect studies of MC-LR, MC-LR-GSH and MC-LR-Cys in vivo.
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei 430070, China. Electronic address: guoxiaochun419@163.com.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Guo
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan 430072, China. Electronic address: xieping@ihb.ac.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Xie
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan 430072, China. Electronic address: chenjun@ihb.ac.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan 430072, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Tuo
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan 430072, China.
authors.forename: Xuwei
authors.initials: X
authors.lastname: Deng
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan 430072, China.
authors.forename: Shangchun
authors.initials: S
authors.lastname: Li
authors.affiliation: Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan 430072, China.
authors.forename: Dezhao
authors.initials: D
authors.lastname: Yu
authors.affiliation: College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zeng
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods; D005978:Glutathione / Q000032:analysis* / Q000378:metabolism*; D057230:Limit of Detection; D008099:Liver / Q000378:metabolism*; D008297:Male; D008387:Marine Toxins; D052998:Microcystins / Q000032:analysis* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D052616:Solid Phase Extraction / Q000379:methods; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D008387:Marine Toxins; D052998:Microcystins; C057862:cyanoginosin LR; D005978:Glutathione
keywords: LC–ESI–MS/MS; Microcystin-LR; Microcystin-LR-Cys; Microcystin-LR-GSH; Quantitative determination; Rat liver