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Miksa IR, Buckley CL, Poppenga RH. Detection of Nonesterified (Free) Fatty Acids in Bovine Serum: Comparative Evaluation of Two Methods. J Vet Diagn Invest 2016; 16:139-44. [PMID: 15053365 DOI: 10.1177/104063870401600208] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A method comparison study for the determination and quantitation of nonesterified fatty acids (NEFAs) in serum, using the commercial “NEFA C” enzymatic test kit, was performed using the spectrophotometric method recommended by the manufacturer and a modified procedure optimized for the use of a microplate reader, a 96-well microtiter plate, and small sample volumes (10 μl). Linearity, sensitivity, and precision using the test kit were determined for each method of detection. The assay was linear from 0 to 1.97 mEq/liter for both procedures, and the limits of detection were determined to be 0.22 (±0.074) and 0.05 (±0.002) mEq/liter for the spectrophotometer and microplate reader, respectively. Pairs of measurements for bovine serum samples were compared and evaluated by a mean difference plot method and not regression analysis, a method that has been shown to be inappropriate for method comparison studies. The difference plot was used to evaluate the systematic bias between the 2 methods. Random error is reported on the basis of SD differences, and “limits of agreement” are used to describe the maximum differences likely to occur between the 2 methods. Results suggest that the microplate reader method can be used reliably in place of the recommended spectrophotometric method. The microplate reader method is preferred because of its high throughput capabilities, simultaneous analysis of all the standards and samples, use of small sample and reagent volumes, and reduction in labor requirements and costs.
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Affiliation(s)
- Irina Rudik Miksa
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, Toxicology, Kennett Square, PA 19348, USA
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2
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Onozato M, Nishikiori M, Iizuka H, Ichiba H, Sadamoto K, Fukushima T. Determination of sex-based differences in serum γ-linolenic [corrected] acid and dihomo-γ-linolenic [corrected] acid using gas chromatography-mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 997:116-21. [PMID: 26113452 DOI: 10.1016/j.jchromb.2015.05.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 05/07/2015] [Accepted: 05/10/2015] [Indexed: 10/23/2022]
Abstract
Because serum unsaturated fatty acids can provide useful information on disease diagnosis, the simultaneous determination of several fatty acids in small volumes of human serum would be beneficial for clinical applications. In the present study, serum fatty acids were extracted with n-heptane/chloroform from 10μL of serum collected from 26 healthy Japanese subjects (11 men, ages 23-37 years; 15 women, ages 18-37 years) after deproteinization with perchloric acid, derivatization to their methyl ester using p-toluenesulfonic acid as an acid catalyst, and subsequent separation and measurement by gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring mode. Nine types of fatty acids (palmitoleic acid [PLA], oleic acid [OA], linoleic [corrected] acid [LA], γ-linolenic acid [GLA], α-linolenic acid [ALA], dihomo-GLA [DGLA], arachidonic acid [AA], eicosapentaenoic acid [EPA], and docosahexaenoic acid [DHA]) were analyzed in the serum within 35 min by GC-MS. The concentrations of these fatty acids in serum ranged from 3.64±0.38μM (GLA) to 413±26.3 μM (LA). Among these nine fatty acids, GLA and DGLA levels were significantly lower in women than in men (p=0.0034 and 0.0012, respectively), suggesting that there may be sex-based differences in the biosynthetic production or metabolic processes of GLA and DGLA in humans.
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Affiliation(s)
- Mayu Onozato
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Minami Nishikiori
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Hideaki Iizuka
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Hideaki Ichiba
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Kiyomi Sadamoto
- Faculty of Pharmaceutical Sciences, Yokohama College of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama-shi, Kanagawa 245-0066, Japan
| | - Takeshi Fukushima
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan.
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3
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Nishikiori M, Iizuka H, Ichiba H, Sadamoto K, Fukushima T. Determination of Free Fatty Acids in Human Serum by HPLC with Fluorescence Detection. J Chromatogr Sci 2014; 53:537-41. [DOI: 10.1093/chromsci/bmu081] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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4
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Tsukamoto Y, Santa T, Yoshida H, Miyano H, Fukushima T, Hirayama K, Imai K, Funatsu T. Synthesis of the isotope-labeled derivatization reagent for carboxylic acids, 7-(N,N-dimethylaminosulfonyl)-4-(aminoethyl)piperazino-2,1,3-benzoxadiazole (d6) [DBD-PZ-NH2 (D)], and its application to the quantification and the determination of relative amount of fatty acids in rat plasma samples by high-performance liquid chromatography/mass spectrometry. Biomed Chromatogr 2006; 20:358-64. [PMID: 16167303 DOI: 10.1002/bmc.574] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The isotope-labeled benzofurazan derivatization reagent for carboxylic acids, 7-(N,N-dimethylaminosulfonyl)-4-(aminoethyl)piperazino-2,1,3-benzoxadiazole (d6) [DBD-PZ-NH2 (D)] was synthesized. DBD-PZ-NH2 (D) was used for the accurate quantification of fatty acids by liquid chromatography/mass spectrometry (LC/MS). The standard fatty acids were derivatized with DBD-PZ-NH2 (D) to the stable isotope-labeled compounds for the fatty acids derivatives of DBD-PZ-NH2 and used for the internal standards. The obtained calibration curves for fatty acids were linear over the range 0.1-200 microM (r2 > 0.999). Fatty acids in plasma samples were determined after derivatization with DBD-PZ-NH2 and analyzed by LC/MS using standard fatty acid DBD-PZ-NH2 (D) derivatives as internal standards. Furthermore, the relative amounts of fatty acids in two plasma samples were determined after derivatization with DBD-PZ-NH2 and DBD-PZ-NH2) (D). The isotope-labeled derivatization reagent was useful for accurate quantification and the determination of relative amounts of the metabolites in biological samples having the target functional group.
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Affiliation(s)
- Yuhki Tsukamoto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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5
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Baena B, Cifuentes A, Barbas C. Analysis of carboxylic acids in biological fluids by capillary electrophoresis. Electrophoresis 2005; 26:2622-36. [PMID: 15934051 DOI: 10.1002/elps.200410329] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This review article addresses the different capillary electrophoretic methods that are being used for the study of both short-chain organic acids (including anionic catecholamine metabolites) and fatty acids in biological samples. This work intends to provide an updated overview (including works published until November 2004) on the recent methodological developments and applications of such procedures together with their main advantages and drawbacks. Moreover, the usefulness of CE analysis of organic acids to study and/or monitor different diseases such as diabetes, new-borns diseases or metabolism disorders is examined. The use of microchip devices and CE-MS couplings for organic acid analysis is also discussed.
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Affiliation(s)
- Beatriz Baena
- Sección Química Analítica, Fac. CC. Experimentales y de la Salud, Universidad San Pablo-CEU, Madrid, Spain
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Nagy K, Jakab A, Fekete J, Vékey K. An HPLC-MS approach for analysis of very long chain fatty acids and other apolar compounds on octadecyl-silica phase using partly miscible solvents. Anal Chem 2005; 76:1935-41. [PMID: 15053654 DOI: 10.1021/ac034944t] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel approach for analyzing underivatized very long chain fatty acids (C16-C26) and other apolar compounds such as triacylglycerols is described. It is based on reversed-phase HPLC separation followed by mass spectrometric detection. Partly miscible solvents are used for stepwise gradient elution starting with a methanol/water and ending with a methanol/n-hexane binary mixture. The developed technique does not need derivatization, and analysis is fast (fatty acids were separated in 2-min-long chromatograms) and robust. The developed method is also very sensitive; a quantitation limit in the low-picogram range was achieved for fatty acids. The separation mechanism and advantages of the suggested technique are discussed and illustrated in the case of blood analysis and plant oil characterization.
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Affiliation(s)
- Kornél Nagy
- Institute of Chemistry, Chemical Research Center, Hungarian Academy of Sciences, H-1025 Pusztaszeri út 59-67, Budapest, Hungary
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7
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Tsukamoto Y, Santa T, Saimaru H, Imai K, Funatsu T. Synthesis of benzofurazan derivatization reagents for carboxylic acids and its application to analysis of fatty acids in rat plasma by high-performance liquid chromatography-electrospray ionization mass spectrometry. Biomed Chromatogr 2005; 19:802-8. [PMID: 15954158 DOI: 10.1002/bmc.523] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The derivatization regents for carboxylic acids, DAABD-AE (4-[2-(N,N-dimethylamino)ethylaminosulfonyl]7-(2-aminoethylamino)-2,1,3-benzoxadiazole), MePZBD-AE ([4-(4-N-methyl)piperazinosulfonyl]-7-(2-aminoethylamino)-2,1,3-benzoxadiazole) and APZBD-NHMe ([4-(4-N-aminoethyl)piperazinosulfonyl]-7-methylamino-2,1,3-benzoxadiazole) were developed for electrospray ionization-mass spectrometry (ESI-MS). The derivatization reaction with fatty acids was completed at 60 degrees C within 30 min. The derivatives of fatty acids were separated on a reversed-phase column and detected with ESI-MS. The detection limits attained for fatty acids were femtomol range and the calibration curves were linear over the range from 0.1 to 100 pmol (r2 > 0.992) for DAABD-AE and MePZBD-AE. DAABD-NHMe was applied to the analysis of fatty acids in rat plasma samples.
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Affiliation(s)
- Yuhki Tsukamoto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Fukushima T, Usui N, Santa T, Imai K. Recent progress in derivatization methods for LC and CE analysis. J Pharm Biomed Anal 2003; 30:1655-87. [PMID: 12485710 DOI: 10.1016/s0731-7085(02)00511-3] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The derivatization procedure with a suitable fluorescence or chemiluminescence reagent is performed for the purpose of increasing the detection sensitivity and selectivity, in high-performance liquid chromatography (HPLC) and/or capillary electrophoresis (CE). In this article, recent derivatization methods and their applications to biosamples are described. In HPLC, femto mol order of mass detection limits are obtained by derivatization. Regarding the fluorescence reagents, the use of water-soluble reagents has been effective to avoid an undesired adsorption in the process of determination of peptides. In CE, the advantages of having extremely low mass detection limits (ranging from atto to yocto mol level) and requiring only a very short analysis time (less than a few minutes) are made possible by using laser-induced fluorescence or near infra-red detections.
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Affiliation(s)
- Takeshi Fukushima
- Laboratory of Bio-Analytical Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Sajiki J, Yonekubo J. Determination of free polyunsaturated fatty acids and their oxidative metabolites by high-performance liquid chromatography (HPLC) and mass spectrometry (MS). Anal Chim Acta 2002. [DOI: 10.1016/s0003-2670(01)01558-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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10
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Toyo’oka T. Fluorescent tagging of physiologically important carboxylic acids, including fatty acids, for their detection in liquid chromatography. Anal Chim Acta 2002. [DOI: 10.1016/s0003-2670(02)00398-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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11
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Kotani A, Kusu F, Takamura K. New electrochemical detection method in high-performance liquid chromatography for determining free fatty acids. Anal Chim Acta 2002. [DOI: 10.1016/s0003-2670(01)01520-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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Derivatization Reactions for Analytes with Various Functional Groups. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0301-4770(02)80020-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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13
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Uchiyama S, Santa T, Okiyama N, Fukushima T, Imai K. Fluorogenic and fluorescent labeling reagents with a benzofurazan skeleton. Biomed Chromatogr 2001; 15:295-318. [PMID: 11507712 DOI: 10.1002/bmc.75] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fluorogenic and fluorescent labeling reagents having a benzofurazan (2,1,3-benzoxadiazole) skeleton such as 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), 4-N,N-dimethylaminosulfonyl-7-fluoro-2,1,3-benzoxadiazole (DBD-F), 4-aminosulfonyl-7-fluoro-2,1,3-benzoxadiazole (ABD-F), ammonium 7-fluoro-2,1,3-benzoxadiazole-4-sulfonate (SBD-F), 4-hydrazino-7-nitro-2,1,3-benzoxadiazole (NBD-H), 4-N,N-dimethylaminosulfonyl-7-hydrazino-2,1,3-benzoxadiazole (DBD-H), 4-nitro-7-N-piperazino-2,1,3-benzoxadiazole (NBD-PZ), 4-N,N-dimethylaminosulfonyl-7-N-piperazino-2,1,3-benzoxadiazole (DBD-PZ), 4-(N-chloroformylmethyl-N-methyl)amino-7-N,N-dimethylaminosulfonyl-2,1,3-benzoxadiazole (DBD-COCl) and 7-N,N-dimethylaminosulfonyl-4-(2,1,3-benzoxadiazolyl) isothiocyanate (DBD-NCS) are reviewed in terms of synthetic method, reactivity, fluorescence characteristics, sensitivity and application to analytes.
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Affiliation(s)
- S Uchiyama
- Laboratory of Bio-Analytical Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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14
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Kotani A, Fuse T, Kusu F. Determination of plasma free fatty acids by high-performance liquid chromatography with electrochemical detection. Anal Biochem 2000; 284:65-9. [PMID: 10933857 DOI: 10.1006/abio.2000.4682] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Determination of free fatty acids (FFAs) in control serum and human plasma was carried out by high-performance liquid chromatography with electrochemical detection. Peak height for palmitic, palmitoleic, stearic, oleic, linoleic, and arachidonic acids at a detection potential of -415 mV vs a saturated calomel electrode showed a linear relation to acid amount in the range 50-1600 pmol. The present method for plasma free fatty acid determination required only 10 microL of plasma sample. The method is simple and the time for blood pretreatment is short. Change in plasma FFA with blood glucose level was monitored before and after meal ingestion by this method, using one male and one female subject. It was possible to rapidly reduce plasma FFA and increase blood glucose subsequent to the meal. The present method is thus shown to have potential for clinical application.
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Affiliation(s)
- A Kotani
- School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1, Horinouchi, Hachioji, Tokyo 192-0392, Japan
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Phillis JW, Song D, O'Regan MH. Effect of hyperglycemia on extracellular levels of amino acids and free fatty acids in the ischemic/reperfused rat cerebral cortex. Brain Res 1999; 837:177-83. [PMID: 10434000 DOI: 10.1016/s0006-8993(99)01700-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study analyzed the effects of pre-existing hyperglycemia on the extracellular levels of glutamate, other amino acids and free fatty acids, including arachidonic acid, in the ischemic/reperfused rat cerebral cortex, using a cortical cup technique. Forebrain cerebral ischemia (20 min) was induced by four vessel occlusion. Glucose (3.4 g/kg) was administered 30 min prior to ischemia. Glucose administration had no effect on basal levels of superfusate amino acids and reduced basal levels of linoleic and oleic acids. Cerebral ischemia elicited increased superfusate levels of aspartate, glutamate, phosphoethanolamine, taurine, gamma-aminobutyric acid (GABA) and arachidonic acid when compared with basal levels. Reperfusion caused a further increase in phosphoethanolamine and arachidonic acid levels and transient increases in linoleic, oleic and palmitic acids. Hyperglycemia resulted in significantly reduced levels of glutamate, phosphoethanolamine, GABA and arachidonic, myristic, palmitic, linoleic and oleic acids during ischemia/reperfusion in comparison with the saline-injected ischemic controls. The results indicate that ischemia/reperfusion-evoked increases in the extracellular levels of glutamate, certain other amino acids and free fatty acids are attenuated by prior systemic glucose administration.
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Affiliation(s)
- J W Phillis
- Department of Physiology, School of Medicine, Wayne State University, 540 E. Canfield, Detroit, MI 48201, USA.
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Saluja I, O'Regan MH, Song D, Phillis JW. Activation of cPLA2, PKC, and ERKs in the rat cerebral cortex during ischemia/reperfusion. Neurochem Res 1999; 24:669-77. [PMID: 10344596 DOI: 10.1023/a:1021004525979] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Release of the excitotoxic amino acid, glutamate, into the extracellular space during ischemia/reperfusion contributes to neuronal injury and death. To gain insights into the signal transduction pathways involved in glutamate release we examined the time course of changes in enzyme levels and activities of cPLA2, PKC and ERKs in the rat cerebral cortex after four vessel (4VO) ischemia followed by reperfusion. Measurement both by enzymatic assay and Western blot analysis showed significant increases in the activity and protein levels of cPLA2 during 10-20 min of ischemia. Activity remained elevated at 10 min and 20 min of reperfusion, whereas cPLA levels had returned to base line levels after 20 min of reperfusion. PKC activity increased significantly in the particulate, but not in the cytosolic, fractions both during ischemia and reperfusion. Increases in PKCgamma levels were recorded in the particulate fraction during ischemia and reperfusion, and in the cytosolic fraction during ischemia. Western blot analysis with a phosphospecific antibody for characterization of MAPK (ERKs) activation revealed significantly increased phosphorylation of ERK1 and ERK2 in the particulate fraction, of ERK2 in the cytosolic fraction, during ischemia and of both enzymes in the particulate and cytosolic fractions after 10 min of reperfusion. The relevance of the results to glutamate release is discussed.
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Affiliation(s)
- I Saluja
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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