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Clauss NJ, Mayer FP, Owens WA, Vitela M, Clarke KM, Bowman MA, Horton RE, Gründemann D, Schmid D, Holy M, Gould GG, Koek W, Sitte HH, Daws LC. Ethanol inhibits dopamine uptake via organic cation transporter 3: Implications for ethanol and cocaine co-abuse. Mol Psychiatry 2023; 28:2934-2945. [PMID: 37308680 PMCID: PMC10615754 DOI: 10.1038/s41380-023-02064-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/20/2022] [Accepted: 03/29/2023] [Indexed: 06/14/2023]
Abstract
Concurrent cocaine and alcohol use is among the most frequent drug combination, and among the most dangerous in terms of deleterious outcomes. Cocaine increases extracellular monoamines by blocking dopamine (DA), norepinephrine (NE) and serotonin (5-HT) transporters (DAT, NET and SERT, respectively). Likewise, ethanol also increases extracellular monoamines, however evidence suggests that ethanol does so independently of DAT, NET and SERT. Organic cation transporter 3 (OCT3) is an emergent key player in the regulation of monoamine signaling. Using a battery of in vitro, in vivo electrochemical, and behavioral approaches, as well as wild-type and constitutive OCT3 knockout mice, we show that ethanol's actions to inhibit monoamine uptake are dependent on OCT3. These findings provide a novel mechanistic basis whereby ethanol enhances the neurochemical and behavioral effects of cocaine and encourage further research into OCT3 as a target for therapeutic intervention in the treatment of ethanol and ethanol/cocaine use disorders.
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Affiliation(s)
- N J Clauss
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - F P Mayer
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK-2200, Denmark
| | - W A Owens
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - M Vitela
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - K M Clarke
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - M A Bowman
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - R E Horton
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - D Gründemann
- Department of Pharmacology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931, Cologne, Germany
| | - D Schmid
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - M Holy
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
| | - G G Gould
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - W Koek
- Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - H H Sitte
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090, Vienna, Austria
- Center for Addiction Research and Science, Medical University Vienna, Waehringerstrasse 13 A, 1090, Vienna, Austria
| | - L C Daws
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA.
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA.
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Nakhla DS, Hussein LA, Magdy N, Abdallah IA, Hassan HE. Precise simultaneous quantification of methadone and cocaine in rat serum and brain tissue samples following their successive i.p. administration. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1048:19-29. [PMID: 28192759 DOI: 10.1016/j.jchromb.2017.01.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 01/26/2017] [Accepted: 01/31/2017] [Indexed: 11/28/2022]
Abstract
A sensitive high-performance liquid chromatography (HPLC) assay with dual UV detection has been developed and validated for the simultaneous quantification of methadone and cocaine in rat serum and brain tissue samples. Liquid-liquid extraction using hexanes was applied for samples extraction with Levo-Tetrahydropalmatine (L-THP) as the internal standard. Chromatographic separation of the analytes was achieved on a reversed-phase Waters Symmetry® C18 column (150mm×4.6mm, 5μm). A gradient elution was employed with a mobile phase consisting of 5mM potassium phosphate containing 0.1% triethylamine (pH=6.5) (A) and acetonitrile (B) with a flow rate of 1mL/min. UV detection was employed at 215nm and 235nm for the determination of methadone and cocaine, respectively. The calibration curves were linear over the range of 0.05-10μg/mL for both methadone and cocaine. The assay was validated according to FDA guidelines for bioanalytical method validation and results were satisfactory and met FDA criteria. Inter-day accuracy values of serum and brain samples ranged from 96.97 to 105.59% while intra-day accuracy values ranged from 91.49 to 111.92%. Stability assays showed that both methadone and cocaine were stable during sample storage, preparation, and analytical procedures. The method was successfully used to analyze biological samples obtained from a drug- drug interaction pharmacokinetics (PK) study conducted in rats to investigate the effect of methadone on cocaine PK. Our method not only can be used for bioanalysis of samples obtained from rats but also can potentially be applied to human biological serum samples to monitor compliance to methadone maintenance therapy (MMT) and to detect possible cocaine-methadone co-abuse.
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Affiliation(s)
- David S Nakhla
- Department of Pharmaceutical Sciences, University of Maryland, School of Pharmacy, Baltimore, MD, United States; Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Misr International University, Cairo, Egypt
| | - Lobna A Hussein
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - N Magdy
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Inas A Abdallah
- Department of Pharmaceutical Sciences, University of Maryland, School of Pharmacy, Baltimore, MD, United States; Department of Analytical Chemistry, Faculty of Pharmacy, University of Sadat City, Sadat City, Egypt
| | - Hazem E Hassan
- Department of Pharmaceutical Sciences, University of Maryland, School of Pharmacy, Baltimore, MD, United States; Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Helwan University, Cairo, Egypt.
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Sun Y, Tang D, Chen H, Zhang F, Fan B, Zhang B, Fang S, Lu Q, Wei Y, Yin J, Yin X. Determination of gemcitabine and its metabolite in extracellular fluid of rat brain tumor by ultra performance liquid chromatography-tandem mass spectrometry using microdialysis sampling after intralesional chemotherapy. J Chromatogr B Analyt Technol Biomed Life Sci 2013; 919-920:10-9. [PMID: 23396113 DOI: 10.1016/j.jchromb.2012.12.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 11/26/2012] [Accepted: 12/09/2012] [Indexed: 10/27/2022]
Abstract
The cytotoxic agent Gemcitabine (2',2'-difluoro-2'-deoxycytidine) has been proved to be effective in the treatment of malignant gliomas. A rapid, sensitive and specific ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) assay using microdialysis sampling was developed and validated to quantify gemcitabine and its major metabolite 2',2'-difluoro-2'-deoxyuridine (dFdU) in Sprague-Dawley rat bearing 9L glioma. Microdialysis probes were surgically implanted into the area of rat brain tumor in the striatal hemisphere, and artificial cerebrospinal fluid was used as a perfusion medium. The samples were analyzed directly by UPLC-MS/MS after the addition of 5-bromouracil as an internal standard (IS). Separation was achieved on Agilent SB-C(18) (50 mm × 2.1mm I.D., 1.8 μm) column at 40 °C using an isocratic elution method with acetonitrile and 0.1% formic acid (4:96, v/v) at a flow rate of 0.2 mL/min. Detection was performed using electrospray ionization in positive ion selected reaction monitoring mode by monitoring the following ion transitions m/z 264.0→112.0 (gemcitabine), m/z 265.1→113.0 (dFdU) and m/z 190.9→173.8 (IS). The calibration curves of gemcitabine and dFdU were linear in the concentration range of 0.66-677.08 ng/mL and 0.31-312.00 ng/mL, respectively. The lower limit of quantification of gemcitabine and dFdU were 0.66 ng/mL and 0.31 ng/mL, respectively. The lower limit of detection of gemcitabine and dFdU were calculated to be 0.2 ng/mL and 0.1 ng/mL, respectively. All the validation data, such as intra- and inter-day precision, accuracy, selectivity and stability, were within the required limits. The validated method was simple, precise and accurate, which was successfully employed to determinate the concentrations of gemcitabine and dFdU in the extracellular fluid of rat brain tumor.
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Affiliation(s)
- Ying Sun
- Key Laboratory of New Drug and Clinical Application, Xuzhou Medical College, No. 209 Tongshan Road, Xuzhou 221004, Jiangsu, China
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Su F, Wang F, Zhu R, Li H. Determination of 5-Hydroxytryptamine, Norepinephrine, Dopamine and Their Metabolites in Rat Brain Tissue by LC–ESI–MS–MS. Chromatographia 2008. [DOI: 10.1365/s10337-008-0879-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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5
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Tomita M, Nakashima MN, Wada M, Nakashima K. Sensitive determination of MDMA and its metabolite MDA in rat blood and brain microdialysates by HPLC with fluorescence detection. Biomed Chromatogr 2007; 21:1016-22. [PMID: 17474141 DOI: 10.1002/bmc.839] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Simultaneous determination of 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA) in rat blood and brain microdialysates by high-performance liquid chromatography with fluorescence detection (HPLC-FL) was developed. Microdialysates were directly subjected to derivatization with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl). The DIB-derivatives of MDMA, MDA and the internal standard, 1-methyl-3-phenylpropylamine (MPPA), were isocratically separated on an ODS column using a mixture of 50 mm phosphate buffer (pH 7.0)-acetonitrile-methanol-2-propanol (50:45:5:2, v/v/v/v %) as an eluent at a flow rate of 1.5 mL/min. The calibration curves of MDA and MDMA spiked to blood and brain microdialysates were linear over the ranges 2.5-500 and 5.0-1000 ng/mL, respectively. The detection limits of MDA and MDMA were 1.2 and 4.2 for blood and 1.3 and 4.8 ng/mL for brain, respectively. Additionally, the intra- and the inter-assay precisions were lower than 5.6% for the blood and brain microdialysates (n = 4). The proposed method was successfully applied for the monitoring of MDMA and its metabolite MDA in rat blood and brain microdialysates, and the pharmacokinetic parameters of MDMA and MDA in the microdialysates after administration of MDMA (5 mg/kg, i.p.) with or without caffeine (20 mg/kg, i.p.) were evaluated.
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Affiliation(s)
- Mamoru Tomita
- Department of Clinical Pharmacy, Course of Pharmaceutical Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
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6
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Chen YF, Chang CH, Wang SC, Tsai TH. Measurement of unbound cocaine in blood, brain and bile of anesthetized rats using microdialysis coupled with liquid chromatography and verified by tandem mass spectrometry. Biomed Chromatogr 2005; 19:402-8. [PMID: 15651094 DOI: 10.1002/bmc.468] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
To investigate the disposition of unbound cocaine in the rat blood, brain and bile, we demonstrate an in vivo multiple sampling microdialysis system coupled with liquid chromatography for cocaine assay and verified by tandem mass spectrometry. Three microdialysis probes were concurrently inserted into the jugular vein, bile duct and brain striatum of each anesthetized rat. After a period of 2 h post-surgical stabilization, cocaine (10 mg kg(-1)) was administered through the femoral vein. Separation of unbound cocaine from various biological fluids was applied to a reversed-phase C(18) column (250 x 4.6 mm I.D., 5 microm). The mobile phase consisted of acetonitrile--10 mm potassium dihydrogen phosphate buffer (25:75, v/v, pH 4.0) and 0.8% diethylamine at a flow rate of 1 mL min(-1). The UV detector wavelength was set at 235 nm. The results indicate that cocaine penetrates the blood--brain barrier with a rapid distribution. However, unbound cocaine in the bile dialysate was not detectable in the UV detection. We therefore use LC--tandem mass spectrometry to detect the bile fluid after cocaine administration (3 mg kg(-1), i.v.). The results indicate that cocaine goes through hepatobiliary excretion.
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Affiliation(s)
- Yen-Fei Chen
- Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan
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7
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Hows MEP, Lacroix L, Heidbreder C, Organ AJ, Shah AJ. High-performance liquid chromatography/tandem mass spectrometric assay for the simultaneous measurement of dopamine, norepinephrine, 5-hydroxytryptamine and cocaine in biological samples. J Neurosci Methods 2004; 138:123-32. [PMID: 15325120 DOI: 10.1016/j.jneumeth.2004.03.021] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2003] [Revised: 03/22/2004] [Accepted: 03/26/2004] [Indexed: 10/26/2022]
Abstract
A rapid liquid chromatography/tandem mass spectrometry (LC-MS/MS) method has been developed for the measurement of dopamine (DA), 5-hydroxytryptamine (5HT) and norepinephrine (NE) in brain microdialysates. The assay has also been utilised for the simultaneous measurement of these neurotransmitters and cocaine in brain dialysates. The neurotransmitters and cocaine were resolved in a single 4-min run using a binary gradient elution profile. The analytes were detected using tandem mass spectrometry in the positive ion electrospray mode. The limits of detection for DA, NE, 5HT and cocaine were 200, 1000, 900 pM and 1 pg ml(-1), respectively.
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Affiliation(s)
- Mark E P Hows
- Computational Analytical and Structural Sciences, Psychiatry CEDD, GlaxoSmithKline, Via A. Fleming 4, 37135 Verona, Italy.
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Fuh MR, Haung CH, Lin SL, Pan WHT. Determination of free-form amphetamine in rat brain by ion-pair liquid chromatography–electrospray mass spectrometry with in vivo microdialysis. J Chromatogr A 2004; 1031:197-201. [PMID: 15058583 DOI: 10.1016/j.chroma.2003.11.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
An ion-pair liquid chromatography-electrospray mass spectrometry (LC-ESI-MS) method with in vivo microdialysis for the determination of free-form amphetamine in rat brain has been developed. A microdialysis probe was surgically implanted into the striatum of the rat and artificial cerebrospinal fluid (aCSF) was used as the perfusion medium. Samples were collected and then analyzed off-line by LC-ESI-MS. A reversed phase C18 column was employed for LC separation. Trifluoroacetic acid (TFA) was added in the mobile phase (acetonitrile-water, 10:90, v/v) as an ion-pair reagent. The ion-pair process disguises the protonated amphetamine cations from the ESI-MS electric field as neutral molecules. Post-column addition of volatile organic acid was utilized to minimize TFA signal suppression effect on ESI-MS detection. More than six-fold enhancement of ESI-MS response was achieved by the post-column addition of propionic acid. Good linearity (0.01-1.00 microg/ml, r2 = 0.99) and detection limit (0.002 microg/ml) were determined. Good precision and accuracy were obtained. The applicability of this newly developed method was demonstrated by continuous monitoring of amphetamine concentrations in rat brain after a single 3.0 mg/kg i.p. administration.
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Affiliation(s)
- Ming-Ren Fuh
- Department of Chemistry, Soochow University, P.O. Box 86-72, Taipei 111, Taiwan.
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Smyth WF, Ramachandran VN, O'Kane E, Coulter D. Characterisation of selected drugs with nitrogen-containing saturated ring structures by use of electrospray ionisation with ion-trap mass spectrometry. Anal Bioanal Chem 2004; 378:1305-12. [PMID: 14740137 DOI: 10.1007/s00216-003-2414-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2003] [Revised: 11/10/2003] [Accepted: 11/12/2003] [Indexed: 11/28/2022]
Abstract
The electrospray ionisation-ion-trap mass spectrometry (ESI-MS(n)) of selected drugs with nitrogen-containing saturated ring structures has been investigated. Sequential product-ion fragmentation experiments (MS(n)) have been performed to elucidate degradation pathways for the [M+H](+) ions and their predominant fragment ions. These MS(n) experiments result in characteristic fragmentations in which functional groups are generally cleaved from the ring systems as neutral molecules such as H(2)O, amines, alkenes, esters, carboxylic acids, etc. When such a nitrogen-containing drug molecule also contains a functional group, such as an ester, that on liberation as a neutral molecule has a significantly lower -Delta H(f) degrees value than that of the corresponding amine then the former is preferentially liberated. Furthermore, when an aromatic entity is present in these drug molecules together with the nitrogen-containing saturated ring structure fragmentation of the latter ring occurs with the former, predictably, being resistant to fragmentation. The structures of fragment ions proposed for ESI-MS(n) can be supported by electrospray ionisation-quadrupole time-of-flight mass spectrometry (ESI-QTOFMS). The data presented in this paper therefore provide useful information on the structure of these heterocyclic compounds which could be used to characterise unknown drug compounds isolated from natural sources, for example.
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Affiliation(s)
- W Franklin Smyth
- School of Biomedical Sciences, University of Ulster, BT52 1SA, Coleraine, N. Ireland, UK.
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Smyth W. Electrospray ionisation mass spectrometric behaviour of selected drugs and their metabolites. Anal Chim Acta 2003. [DOI: 10.1016/s0003-2670(02)01474-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Cabovska B, Norman AB, Stalcup AM. Separation of cocaine stereoisomers by capillary electrophoresis using sulfated cyclodextrins. Anal Bioanal Chem 2003; 376:134-7. [PMID: 12734626 DOI: 10.1007/s00216-003-1850-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2002] [Revised: 01/08/2003] [Accepted: 01/21/2003] [Indexed: 11/24/2022]
Abstract
A capillary electrophoretic method for the separation of cocaine and its stereoisomers was developed. In this study, the effect of organic modifier was also investigated. The separation was achieved using 1% sulfated cyclodextrin, 10 mmol L(-1) phosphate buffer, 10% methanol at pH 3. The method provides good reproducibility and easy application.
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Affiliation(s)
- B Cabovska
- Department of Chemistry, University of Cincinnati, P.O. Box 210172, OH 45221-0172, USA
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Kennedy RT, Watson CJ, Haskins WE, Powell DH, Strecker RE. In vivo neurochemical monitoring by microdialysis and capillary separations. Curr Opin Chem Biol 2002; 6:659-65. [PMID: 12413551 DOI: 10.1016/s1367-5931(02)00373-3] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Microdialysis is valuable for studying the neurochemical changes underlying behavior. Recent advances include the application of the high-sensitivity methods of capillary electrophoresis and capillary liquid chromatography with mass spectrometry to dialysate analysis. These methods have improved temporal resolution, spatial resolution, multi-analyte capability and potential for compound discovery.
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Affiliation(s)
- Robert T Kennedy
- Department of Chemistry and Pharmacology, 930 North University, University of Michigan, Ann Arbor 48109-1055, USA.
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Daws LC, Callaghan PD, Morón JA, Kahlig KM, Shippenberg TS, Javitch JA, Galli A. Cocaine increases dopamine uptake and cell surface expression of dopamine transporters. Biochem Biophys Res Commun 2002; 290:1545-50. [PMID: 11820798 DOI: 10.1006/bbrc.2002.6384] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In HEK 293 cells expressing the human dopamine transporter (DAT), a 10-min incubation with 10 microM cocaine followed by extensive washing resulted in a 30% increase in [3H]dopamine (DA) uptake as well as an increase in cell surface DAT in biotinylation experiments. Consistent with this novel regulation, [3H]DA uptake into synaptosomes prepared from the nucleus accumbens of rats sacrificed 30 min after a single cocaine injection (30 mg/kg) was significantly increased compared to controls (56% increase in V(max), no change in K(m)). In addition, DA clearance in the striatum of anesthetized rats was increased after local application of a low (3 pmol) but not high (65 pmol) dose of cocaine, presumably as a result of mobilization of DAT to the cell surface. Cocaine-induced increases in cell surface expression of DAT and associated changes in DA clearance represent a novel mechanism that may play a role in its addictive properties.
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Affiliation(s)
- Lynette C Daws
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, MC 7764, San Antonio, Texas 78229-3900, USA
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Deguchi Y. Application of In Vivo Brain Microdialysis to the Study of Blood-brain Barrier Transport of Drugs. Drug Metab Pharmacokinet 2002; 17:395-407. [PMID: 15618691 DOI: 10.2133/dmpk.17.395] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recent advances in blood-brain barrier (BBB) research have led to a new understanding of drug transport processes at the BBB. The BBB acts as a dynamic regulatory interface at which nutrients necessary for neural activity are actively taken up into the brain from the blood circulation, and actively excludes metabolites that might interfere with the maintenance of brain homeostasis. Such influx and efflux transport functions at the BBB would also control the concentrations of various drugs in the brain interstitial fluid (ISF), which are an important determinant of the central nervous system (CNS) effects. Thus, direct measurement of the brain ISF concentration of drugs can provide significant information for clarifying the influx and efflux transport functions of drugs across the BBB. Although several experimental techniques have been developed to investigate transport functions across the BBB, in vivo brain microdialysis seems to be one of the most suitable techniques for characterizing the influx and efflux transport functions across the BBB under physiological and pathological conditions. This review covers studies during the past decade, in which the influx and efflux transport of drugs across the BBB was kinetically and mechanistically evaluated by means of the brain microdialysis technique. Some applications of brain microdialysis to studies on neuronal function and neurotherapeutics are also included.
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Affiliation(s)
- Yoshiharu Deguchi
- Department of Drug Disposition & Pharmacokinetics, School of Pharmaceutical Sciences, Teikyo University, Tsukui-gun, Kanagawa, Japan.
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Benkestock K, Edlund PO, Roeraade J. On-line microdialysis for enhanced resolution and sensitivity during electrospray mass spectrometry of non-covalent complexes and competitive binding studies. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2002; 16:2054-2059. [PMID: 12391580 DOI: 10.1002/rcm.832] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Many proteins and macromolecules easily form metal adduct ions which impairs their analysis by mass spectrometry. The present study describes how the formation of undesired adducts can be minimized by on-line microdialysis for non-covalent binding studies of macromolecules with low molecular mass ligands with electrospray ionization mass spectrometry (ESI-MS). The technique was indispensable for protein-ligand studies due to reduction of unwanted adduct ions, and thus gave excellent resolution and a sensitivity improvement of at least 5 times. The core of the analytical system was a modified microdialysis device, which was operated in countercurrent mode. A novel technique based on microdialysis for competitive binding studies is also presented. The non-covalent complex between a protein and a ligand was formed in the sample vial prior to analysis. The complex was injected into an on-line microdialysis system where a competitive ligand was administered in the dialysis buffer outside of the fiber. The second ligand competitively displaced the first ligand through transport via the wall of the dialysis fiber, and the intact complexes were detected by ESI-MS.
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Affiliation(s)
- Kurt Benkestock
- Biovitrum AB, Chemical Technologies, SE-112 76 Stockholm, Sweden.
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Current awareness in phytochemical analysis. PHYTOCHEMICAL ANALYSIS : PCA 2001; 12:286-291. [PMID: 11708301 DOI: 10.1002/pca.556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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