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Stadulytė A, Alcaide-Corral CJ, Walton T, Lucatelli C, Tavares AAS. Analysis of PK11195 concentrations in rodent whole blood and tissue samples by rapid and reproducible chromatographic method to support target-occupancy PET studies. J Chromatogr B Analyt Technol Biomed Life Sci 2019; 1118-1119:33-39. [PMID: 31005772 PMCID: PMC6522057 DOI: 10.1016/j.jchromb.2019.04.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 04/05/2019] [Accepted: 04/11/2019] [Indexed: 12/24/2022]
Abstract
In Positron Emission Tomography (PET) research, it is important to assess not only pharmacokinetics of a radiotracer in vivo, but also of the drugs used in blocking/displacement PET studies. Typically, pharmacokinetic/pharmacodynamic (PK/PD) analyses of drugs used in rodent PET studies are based on population average pharmacokinetic profiles of the drugs due to limited blood volume withdrawal while simultaneously maintaining physiological homeostasis. This likely results in bias of PET data quantification, including unknown bias of target occupancy (TO) measurements. This study aimed to develop a High Performance Liquid Chromatography (HPLC) method for PK/PD quantification of drugs used in preclinical rodent PET research, specifically the translocator 18 kDa protein (TSPO) selective drug, PK11195, that used sub-millilitre blood volumes. The lowest detection limit for the proposed HPLC method ranged between 7.5 and 10 ng/mL depending on the method used to calculate the limit of detection, and the measured average relative standard deviation for intermediate precision was equal to 17.2%. Most importantly, we were able to demonstrate a significant difference between calculated PK11195 concentrations at 0.5, 1, 2, 3, 5, 15 and 30 min post-administration and individually measured whole blood levels (significance level range from p < 0.05 to p < 0.001; one-way ANOVA, Dunnet's post hoc test, p < 0.05). The HPLC method developed here uses sub-millilitre sample volumes to reproducibly assess PK/PD of PK11195 in rodent blood. This study highlights the importance of individually measured PK/PD drug concentrations when quantifying the TO from blocking/displacement rodent PET experiments.
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Affiliation(s)
- Agnė Stadulytė
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, UK; Edinburgh Preclinical Imaging (EPI), University of Edinburgh, UK.
| | - Carlos José Alcaide-Corral
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, UK; Edinburgh Preclinical Imaging (EPI), University of Edinburgh, UK
| | - Tashfeen Walton
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, UK; Edinburgh Imaging, Queen's Medical Research Institute, University of Edinburgh, UK
| | - Christophe Lucatelli
- Edinburgh Imaging, Queen's Medical Research Institute, University of Edinburgh, UK
| | - Adriana Alexandre S Tavares
- University/BHF Centre for Cardiovascular Science, University of Edinburgh, UK; Edinburgh Preclinical Imaging (EPI), University of Edinburgh, UK
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Magnus CJ, Lee PH, Bonaventura J, Zemla R, Gomez JL, Ramirez MH, Hu X, Galvan A, Basu J, Michaelides M, Sternson SM. Ultrapotent chemogenetics for research and potential clinical applications. SCIENCE (NEW YORK, N.Y.) 2019; 364:science.aav5282. [PMID: 30872534 DOI: 10.1126/science.aav5282] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 02/15/2019] [Indexed: 12/11/2022]
Abstract
Chemogenetics enables noninvasive chemical control over cell populations in behaving animals. However, existing small-molecule agonists show insufficient potency or selectivity. There is also a need for chemogenetic systems compatible with both research and human therapeutic applications. We developed a new ion channel-based platform for cell activation and silencing that is controlled by low doses of the smoking cessation drug varenicline. We then synthesized subnanomolar-potency agonists, called uPSEMs, with high selectivity for the chemogenetic receptors. uPSEMs and their receptors were characterized in brains of mice and a rhesus monkey by in vivo electrophysiology, calcium imaging, positron emission tomography, behavioral efficacy testing, and receptor counterscreening. This platform of receptors and selective ultrapotent agonists enables potential research and clinical applications of chemogenetics.
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Affiliation(s)
- Christopher J Magnus
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Peter H Lee
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Jordi Bonaventura
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Roland Zemla
- Neuroscience Institute, New York University, New York, NY 10016, USA.,Medical Scientist Training Program, New York University School of Medicine, New York, NY 10016, USA
| | - Juan L Gomez
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Melissa H Ramirez
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Xing Hu
- Yerkes National Primate Research Center and Department of Neurology, Emory University, Atlanta, GA 30329, USA
| | - Adriana Galvan
- Yerkes National Primate Research Center and Department of Neurology, Emory University, Atlanta, GA 30329, USA
| | - Jayeeta Basu
- Neuroscience Institute, New York University, New York, NY 10016, USA.,Department of Neuroscience and Physiology, New York University Langone Medical Center, New York, NY 10016, USA
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA.,Department of Psychiatry & Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Scott M Sternson
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA.
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Awwad HM, Kirsch SH, Geisel J, Obeid R. Measurement of concentrations of whole blood levels of choline, betaine, and dimethylglycine and their relations to plasma levels. J Chromatogr B Analyt Technol Biomed Life Sci 2014; 957:41-5. [PMID: 24674988 DOI: 10.1016/j.jchromb.2014.02.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 02/11/2014] [Accepted: 02/20/2014] [Indexed: 11/24/2022]
Abstract
We aimed at developing a method for the measurement of choline and its metabolites in whole blood (WB). After an extraction step, quantification of choline, betaine, and dimethylglycine (DMG) was performed using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Plasma and WB metabolites were evaluated in a group of 61 elderly people. The calibration curves were linear (r(2)>0.997) for all compounds. The inter- and intra-assay coefficients of variation for all analytes were <10%. The recoveries were >90% and the relative matrix effect were ≤4.0%. The median concentrations of choline, betaine, and DMG were 11.3, 27.8, and 5.9μmol/L in plasma and 66.6, 165, and 13.7μmol/L in WB, respectively. There were positive correlations between WB and plasma markers; for choline (r=0.42), betaine (r=0.61), and DMG (r=0.56) (all p≤0.001). The concentrations of betaine in WB and plasma were significantly higher in men than in women. The concentrations of WB choline and DMG did not differ significantly according to sex. In conclusion, we have established a reliable method for measuring choline metabolites in WB. The concentrations of WB choline, betaine, and DMG seem to reflect intracellular concentrations of these metabolites.
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Affiliation(s)
- Hussain Mohamad Awwad
- Saarland University Hospital, Department of Clinical Chemistry and Laboratory Medicine, Building 57, 66421 Homburg/Saar, Germany.
| | - Susanne H Kirsch
- Saarland University Hospital, Department of Clinical Chemistry and Laboratory Medicine, Building 57, 66421 Homburg/Saar, Germany
| | - Juergen Geisel
- Saarland University Hospital, Department of Clinical Chemistry and Laboratory Medicine, Building 57, 66421 Homburg/Saar, Germany
| | - Rima Obeid
- Saarland University Hospital, Department of Clinical Chemistry and Laboratory Medicine, Building 57, 66421 Homburg/Saar, Germany.
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Danne O, Möckel M. Choline in acute coronary syndrome: an emerging biomarker with implications for the integrated assessment of plaque vulnerability. Expert Rev Mol Diagn 2010; 10:159-71. [PMID: 20214535 DOI: 10.1586/erm.10.2] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Whole-blood choline, plasma choline and serum choline are emerging biomarkers in acute coronary syndrome related to coronary plaque instability with platelet thrombus formation and ischemia. Whole-blood choline is an early predictor for cardiac events, which adds to troponins, natriuretic peptides and inflammatory markers. Serum choline is highly predictive for myocardial infarction and discriminates high- from low-risk subgroups in troponin-positive patients. Choline is a candidate marker to aid decision making in the emergency room in the upcoming era of sensitive troponin tests and the growing need to differentiate between ischemic and nonischemic etiologies of troponin elevations. The integrated approach of in vitro choline measurement in combination with advanced techniques of in vivo choline imaging represents a novel future strategy for detecting vulnerable plaques. This paper provides an up-to-date review of choline in acute coronary syndrome including key aspects of pathophysiology, analytical methods, clinical studies and implications for the integrated assessment of plaque vulnerability.
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Affiliation(s)
- Oliver Danne
- Department of Medicine, Internal Intensive Care and Nephrology, Charité - Universitätsmedizin Berlin/Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany.
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