1
|
Matsumoto KI, Nakanishi I, Zhelev Z, Bakalova R, Aoki I. Nitroxyl Radical as a Theranostic Contrast Agent in Magnetic Resonance Redox Imaging. Antioxid Redox Signal 2022; 36:95-121. [PMID: 34148403 PMCID: PMC8792502 DOI: 10.1089/ars.2021.0110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Significance:In vivo assessment of paramagnetic and diamagnetic conversions of nitroxyl radicals based on cyclic redox mechanism can be an index of tissue redox status. The redox mechanism of nitroxyl radicals, which enables their use as a normal tissue-selective radioprotector, is seen as being attractive on planning radiation therapy. Recent Advances:In vivo redox imaging using nitroxyl radicals as redox-sensitive contrast agents has been developed to assess tissue redox status. Chemical and biological behaviors depending on chemical structures of nitroxyl radical compounds have been understood in detail. Polymer types of nitroxyl radical contrast agents and/or nitroxyl radical-labeled drugs were designed for approaching theranostics. Critical Issues: Nitroxyl radicals as magnetic resonance imaging (MRI) contrast agents have several advantages compared with those used in electron paramagnetic resonance (EPR) imaging, while support by EPR spectroscopy is important to understand information from MRI. Redox-sensitive paramagnetic contrast agents having a medicinal benefit, that is, nitroxyl-labeled drug, have been developed and proposed. Future Directions: A development of suitable nitroxyl contrast agent for translational theranostic applications with high reaction specificity and low normal tissue toxicity is under progress. Nitroxyl radicals as redox-sensitive magnetic resonance contrast agents can be a useful tool to detect an abnormal tissue redox status such as disordered oxidative stress. Antioxid. Redox Signal. 36, 95-121.
Collapse
Affiliation(s)
- Ken-Ichiro Matsumoto
- Quantitative RedOx Sensing Group, Department of Radiation Regulatory Science Research, National Institute of Radiological Sciences, Quantum Life and Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology, Chiba-shi, Japan
| | - Ikuo Nakanishi
- Quantum RedOx Chemistry Group, Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology, Chiba-shi, Japan
| | - Zhivko Zhelev
- Medical Faculty, Trakia University, Stara Zagora, Bulgaria.,Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Rumiana Bakalova
- Functional and Molecular Imaging Goup, Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology, Chiba-shi, Japan
| | - Ichio Aoki
- Functional and Molecular Imaging Goup, Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology, Chiba-shi, Japan
| |
Collapse
|
2
|
Weaver J, Liu KJ. A Review of Low-Frequency EPR Technology for the Measurement of Brain pO2 and Oxidative Stress. APPLIED MAGNETIC RESONANCE 2021; 52:1379-1394. [PMID: 35340811 PMCID: PMC8945541 DOI: 10.1007/s00723-021-01384-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/24/2021] [Accepted: 06/30/2021] [Indexed: 06/14/2023]
Abstract
EPR can uniquely measure paramagnetic species. Although commercial EPR was introduced in 1950s, the early studies were mostly restricted to chemicals in solution or cellular experiments using X-band EPR equipment. Due to its limited penetration (<1 mm), experiments with living animals were almost impossible. To overcome these difficulties, Swartz group, along with several other leaders in field, pioneered the technology of low frequency EPR (e.g., L-band, 1-2 GHz). The development of low frequency EPR and the associated probes have dramatically expanded the application of EPR technology into the biomedical research field, providing answers to important scientific questions by measuring specific parameters that are impossible or very difficult to obtain by other approaches. In this review, which is aimed at highlighting the seminal contribution from Swartz group over the last several decades, we will focus on the development of EPR technology that was designed to deal with the potential challenges arising from conducting EPR spectroscopy in living animals. The second half of the review will be concentrated on the application of low frequency EPR in measuring cerebral tissue pO2 changes and oxidative stress in various physiological and pathophysiological conditions in the brain of animal disease models.
Collapse
Affiliation(s)
- John Weaver
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131
| | - Ke Jian Liu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131
| |
Collapse
|
3
|
Saito K, Okazaki S, Tachibana Y, Anzai K, Ozawa T, Takeshita K. In vivo ESR imaging of redox status in mice after X-ray irradiation, measured by acyl-protected hydroxylamine probe, ACP. Free Radic Biol Med 2020; 160:596-603. [PMID: 32891759 DOI: 10.1016/j.freeradbiomed.2020.08.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 08/27/2020] [Accepted: 08/30/2020] [Indexed: 11/30/2022]
Abstract
More detailed investigations on the in vivo redox status are needed to elucidate the mechanisms contributing to damage caused by ionizing radiation. In the present study, the in vivo redox status of mice was examined using in vivo electron spin resonance (ESR) imaging after an intraperitoneal injection of 1-acetoxy-3-carbamoyl-2,2,5,5-tetramethylpyrrolidine (ACP) as a probe. ACP is easily hydrolyzed to its hydroxylamine form in the mouse body, and the interconversion between hydroxylamine and the corresponding nitroxyl radical reflects the biological redox status. Liver damage, based on changes in liver weight and plasma aspartate aminotransferase levels, was detected in mice 4 days after X-ray irradiation at 7.5 Gy. ESR imaging showed that the signal intensity of the nitroxyl radical was high at the liver area in both damaged and healthy mice after administration of ACP. Whereas the signal decayed at the liver area for healthy mouse, the decay was negligible in damaged mice. Unlike healthy mouse, signal in the chest for damaged mouse increased with time. The distribution of the sum of hydroxylamine and the nitroxyl radical was similar in damaged and healthy mice. X-ray irradiation slightly lowered the reduction activity of the liver microsomal fraction for the nitroxyl radical. Thiobarbituric acid reactive substances in the liver were higher in damaged mice than in healthy mice; however, no significant differences were noted in reduced glutathione. The present results indicate that the redox status of mice exposed to X-ray irradiation is more oxidative than that in healthy mice.
Collapse
Affiliation(s)
- Keita Saito
- National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Shoko Okazaki
- Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1 Ikeda, Kumamoto, 860-0082, Japan
| | - Yoko Tachibana
- Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1 Ikeda, Kumamoto, 860-0082, Japan
| | - Kazunori Anzai
- National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan; Nihon Pharmaceutical University, 10281 Komuro, Ina-machi, Kita-Adachi-gun, Saitama, 362-0806, Japan
| | - Toshihiko Ozawa
- National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan; Nihon Pharmaceutical University, 10281 Komuro, Ina-machi, Kita-Adachi-gun, Saitama, 362-0806, Japan
| | - Keizo Takeshita
- National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan; Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1 Ikeda, Kumamoto, 860-0082, Japan.
| |
Collapse
|
4
|
Uchida T, Togashi H, Kuroda Y, Yamashita A, Itoh N, Haga K, Sadahiro M, Kayama T. In vivo analysis of redox status in organs - from bench to bedside. Free Radic Res 2020; 54:961-968. [PMID: 32458704 DOI: 10.1080/10715762.2020.1772470] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Reactive oxygen species (ROS) such as superoxide, hydroxyl radical, and hydrogen peroxide play an important role in the maintenance of life. However, production of excessive ROS and/or deficiency of the antioxidant system lead to oxidative stress and cause a variety of diseases. In the present study, we used electron spin resonance (ESR) to detect ROS in vivo to clarify its roles in redox dynamics and organ damage. However, the limited permeability of microwaves and low anatomic resolution of ESR equipment made it difficult to apply clinically. Nitroxide is widely used as a sensitive redox sensor for in vivo ESR analysis. The unpaired electrons of nitroxide are known to cause the T1 relaxation time-shortening effect of water protons, creating magnetic resonance imaging (MRI) effects. The remarkable development of MRI has facilitated the spatiotemporal analysis of nitroxide, which was previously impossible. In a rat model, we have been able to image and analyze the process of nitroxide reduction using MRI. MRI using nitroxide as a contrast medium is considered to be clinically applicable for evaluation of organ redox, imaging of ROS (which cause organ damage), and evaluation of therapeutic effects. In this review, we describe current advances in the analysis of in vivo redox capacity in animals using ESR and MRI equipment. We consider that redox evaluation using MRI can contribute to advances in clinical medicine.
Collapse
Affiliation(s)
- Tetsuro Uchida
- Second Department of Surgery, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Hitoshi Togashi
- Health Administration Center, Yamagata University, Yamagata, Japan
| | - Yoshinori Kuroda
- Second Department of Surgery, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Atsushi Yamashita
- Second Department of Surgery, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Nanami Itoh
- Health Administration Center, Yamagata University, Yamagata, Japan
| | - Kazuyuki Haga
- Radiation Department, Yamagata University Hospital, Yamagata, Japan
| | - Mitsuaki Sadahiro
- Second Department of Surgery, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Takamasa Kayama
- Global Center of Excellence, Faculty of Medicine, Yamagata University, Yamagata, Japan
| |
Collapse
|
5
|
Merging Preclinical EPR Tomography with other Imaging Techniques. Cell Biochem Biophys 2019; 77:187-196. [PMID: 31440878 PMCID: PMC6742609 DOI: 10.1007/s12013-019-00880-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 07/30/2019] [Indexed: 12/21/2022]
Abstract
This paper presents a survey of electron paramagnetic resonance (EPR) image registration. Image registration is the process of overlaying images (two or more) of the same scene taken at different times, from different viewpoints and/or different techniques. EPR-imaging (EPRI) techniques belong to the functional-imaging modalities and therefore suffer from a lack of anatomical reference which is mandatory in preclinical imaging. For this reason, it is necessary to merging EPR images with other modalities which allow for obtaining anatomy images. Methodological analysis and review of the literature were done, providing a summary for developing a good foundation for research study in this field which is crucial in understanding the existing levels of knowledge. Out of these considerations, the aim of this paper is to enhance the scientific community’s understanding of the current status of research in EPR preclinical image registration and also communicate to them the contribution of this research in the field of image processing.
Collapse
|
6
|
Molecular Probes for Evaluation of Oxidative Stress by In Vivo EPR Spectroscopy and Imaging: State-of-the-Art and Limitations. MAGNETOCHEMISTRY 2019. [DOI: 10.3390/magnetochemistry5010013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Oxidative stress, defined as a misbalance between the production of reactive oxygen species and the antioxidant defenses of the cell, appears as a critical factor either in the onset or in the etiology of many pathological conditions. Several methods of detection exist. However, they usually rely on ex vivo evaluation or reports on the status of living tissues only up to a few millimeters in depth, while a whole-body, real-time, non-invasive monitoring technique is required for early diagnosis or as an aid to therapy (to monitor the action of a drug). Methods based on electron paramagnetic resonance (EPR), in association with molecular probes based on aminoxyl radicals (nitroxides) or hydroxylamines especially, have emerged as very promising to meet these standards. The principles involve monitoring the rate of decrease or increase of the EPR signal in vivo after injection of the nitroxide or the hydroxylamine probe, respectively, in a pathological versus a control situation. There have been many successful applications in various rodent models. However, current limitations lie in both the field of the technical development of the spectrometers and the molecular probes. The scope of this review will mainly focus on the latter.
Collapse
|
7
|
Three-dimensional electron spin resonance imaging of endogenous nitric oxide radicals generated in living plants. BIOPHYSICS REPORTS 2018. [DOI: 10.1007/s41048-018-0051-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022] Open
|
8
|
Dikalov SI, Polienko YF, Kirilyuk I. Electron Paramagnetic Resonance Measurements of Reactive Oxygen Species by Cyclic Hydroxylamine Spin Probes. Antioxid Redox Signal 2018; 28:1433-1443. [PMID: 29037084 PMCID: PMC5910043 DOI: 10.1089/ars.2017.7396] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
SIGNIFICANCE Oxidative stress contributes to numerous pathophysiological conditions such as development of cancer, neurodegenerative, and cardiovascular diseases. A variety of measurements of oxidative stress markers in biological systems have been developed; however, many of these methods are not specific, can produce artifacts, and do not directly detect the free radicals and reactive oxygen species (ROS) that cause oxidative stress. Electron paramagnetic resonance (EPR) is a unique tool that allows direct measurements of free radical species. Cyclic hydroxylamines are useful and convenient molecular probes that readily react with ROS to produce stable nitroxide radicals, which can be quantitatively measured by EPR. In this work, we critically review recent applications of various cyclic hydroxylamine spin probes in biology to study oxidative stress, their advantages, and the shortcomings. Recent Advances: In the past decade, a number of new cyclic hydroxylamine spin probes have been developed and their successful application for ROS measurement using EPR has been published. These new state-of-the-art methods provide improved selectivity and sensitivity for in vitro and in vivo studies. CRITICAL ISSUES Although cyclic hydroxylamine spin probes EPR application has been previously described, there has been lack of translation of these new methods into biomedical research, limiting their widespread use. This work summarizes "best practice" in applications of cyclic hydroxylamine spin probes to assist with EPR studies of oxidative stress. FUTURE DIRECTIONS Additional studies to advance hydroxylamine spin probes from the "basic science" to biomedical applications are needed and could lead to better understanding of pathological conditions associated with oxidative stress. Antioxid. Redox Signal. 28, 1433-1443.
Collapse
Affiliation(s)
- Sergey I Dikalov
- 1 Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Yuliya F Polienko
- 2 Laboratory of Nitrogen Compounds, Novosibirsk Institute of Organic Chemistry , Novosibirsk, Russia .,3 Department of Organic Chemistry, Novosibirsk State University , Novosibirsk, Russia
| | - Igor Kirilyuk
- 2 Laboratory of Nitrogen Compounds, Novosibirsk Institute of Organic Chemistry , Novosibirsk, Russia .,3 Department of Organic Chemistry, Novosibirsk State University , Novosibirsk, Russia
| |
Collapse
|
9
|
Stamenković S, Pavićević A, Mojović M, Popović-Bijelić A, Selaković V, Andjus P, Bačić G. In vivo EPR pharmacokinetic evaluation of the redox status and the blood brain barrier permeability in the SOD1 G93A ALS rat model. Free Radic Biol Med 2017; 108:258-269. [PMID: 28366802 DOI: 10.1016/j.freeradbiomed.2017.03.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/25/2017] [Accepted: 03/27/2017] [Indexed: 12/14/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder affecting the motor pathways of the central nervous system. Although a number of pathophysiological mechanisms have been described in the disease, post mortem and animal model studies indicate blood-brain barrier (BBB) disruption and elevated production of reactive oxygen species as major contributors to disease pathology. In this study, the BBB permeability and the brain tissue redox status of the SOD1G93A ALS rat model in the presymptomatic (preALS) and symptomatic (ALS) stages of the disease were investigated by in vivo EPR spectroscopy using three aminoxyl radicals with different cell membrane and BBB permeabilities, Tempol, 3-carbamoyl proxyl (3CP), and 3-carboxy proxyl (3CxP). Additionally, the redox status of the two brain regions previously implicated in disease pathology, brainstem and hippocampus, was investigated by spectrophotometric biochemical assays. The EPR results indicated that among the three spin probes, 3CP is the most suitable for reporting the intracellular redox status changes, as Tempol was reduced in vivo within minutes (t1/2 =2.0±0.5min), thus preventing reliable kinetic modeling, whereas 3CxP reduction kinetics gave divergent conclusions, most probably due to its membrane impermeability. It was observed that the reduction kinetics of 3CP in vivo, in the head of preALS and ALS SOD1G93A rats was altered compared to the controls. Pharmacokinetic modeling of 3CP reduction in vivo, revealed elevated tissue distribution and tissue reduction rate constants indicating an altered brain tissue redox status, and possibly BBB disruption in these animals. The preALS and ALS brain tissue homogenates also showed increased nitrilation, superoxide production, lipid peroxidation and manganese superoxide dismutase activity, and a decreased copper-zinc superoxide dismutase activity. The present study highlights in vivo EPR spectroscopy as a reliable tool for the investigation of changes in BBB permeability and for the unprecedented in vivo monitoring of the brain tissue redox status, as early markers of ALS.
Collapse
Affiliation(s)
- Stefan Stamenković
- University of Belgrade - Faculty of Biology, Center for Laser Microscopy, Studentski trg 3, 11158 Belgrade, Serbia
| | - Aleksandra Pavićević
- University of Belgrade - Faculty of Physical Chemistry, EPR Laboratory, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Miloš Mojović
- University of Belgrade - Faculty of Physical Chemistry, EPR Laboratory, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Ana Popović-Bijelić
- University of Belgrade - Faculty of Physical Chemistry, EPR Laboratory, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Vesna Selaković
- Institute for Medical Research, Military Medical Academy, Crnotravska 17, 11000 Belgrade, Serbia
| | - Pavle Andjus
- University of Belgrade - Faculty of Biology, Center for Laser Microscopy, Studentski trg 3, 11158 Belgrade, Serbia.
| | - Goran Bačić
- University of Belgrade - Faculty of Physical Chemistry, EPR Laboratory, Studentski trg 12-16, 11158 Belgrade, Serbia
| |
Collapse
|
10
|
Maulucci G, Bačić G, Bridal L, Schmidt HH, Tavitian B, Viel T, Utsumi H, Yalçın AS, De Spirito M. Imaging Reactive Oxygen Species-Induced Modifications in Living Systems. Antioxid Redox Signal 2016; 24:939-58. [PMID: 27139586 PMCID: PMC4900226 DOI: 10.1089/ars.2015.6415] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
SIGNIFICANCE Reactive Oxygen Species (ROS) may regulate signaling, ion channels, transcription factors, and biosynthetic processes. ROS-related diseases can be due to either a shortage or an excess of ROS. RECENT ADVANCES Since the biological activity of ROS depends on not only concentration but also spatiotemporal distribution, real-time imaging of ROS, possibly in vivo, has become a need for scientists, with potential for clinical translation. New imaging techniques as well as new contrast agents in clinically established modalities were developed in the previous decade. CRITICAL ISSUES An ideal imaging technique should determine ROS changes with high spatio-temporal resolution, detect physiologically relevant variations in ROS concentration, and provide specificity toward different redox couples. Furthermore, for in vivo applications, bioavailability of sensors, tissue penetration, and a high signal-to-noise ratio are additional requirements to be satisfied. FUTURE DIRECTIONS None of the presented techniques fulfill all requirements for clinical translation. The obvious way forward is to incorporate anatomical and functional imaging into a common hybrid-imaging platform. Antioxid. Redox Signal. 24, 939-958.
Collapse
Affiliation(s)
- Giuseppe Maulucci
- 1 Institute of Physics, Catholic University of Sacred Heart , Roma, Italy
| | - Goran Bačić
- 2 Faculty of Physical Chemistry, University of Belgrade , Belgrade, Serbia
| | - Lori Bridal
- 3 Laboratoire d'Imagerie Biomédicale, Sorbonne Universités and UPMC Univ Paris 06 and CNRS and INSERM , Paris, France
| | - Harald Hhw Schmidt
- 4 Department of Pharmacology and Personalised Medicine, CARIM, Faculty of Health, Medicine & Life Science, Maastricht University , Maastricht, the Netherlands
| | - Bertrand Tavitian
- 5 Laboratoire de Recherche en Imagerie, Université Paris Descartes, Hôpital Européen Georges Pompidou , Service de Radiologie, Paris, France
| | - Thomas Viel
- 5 Laboratoire de Recherche en Imagerie, Université Paris Descartes, Hôpital Européen Georges Pompidou , Service de Radiologie, Paris, France
| | - Hideo Utsumi
- 6 Innovation Center for Medical Redox Navigation, Kyushu University , Fukuoka, Japan
| | - A Süha Yalçın
- 7 Department of Biochemistry, School of Medicine, Marmara University , İstanbul, Turkey
| | - Marco De Spirito
- 1 Institute of Physics, Catholic University of Sacred Heart , Roma, Italy
| |
Collapse
|
11
|
Bačić G, Pavićević A, Peyrot F. In vivo evaluation of different alterations of redox status by studying pharmacokinetics of nitroxides using magnetic resonance techniques. Redox Biol 2015; 8:226-42. [PMID: 26827126 PMCID: PMC4753396 DOI: 10.1016/j.redox.2015.10.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 10/25/2015] [Indexed: 12/22/2022] Open
Abstract
Free radicals, particularly reactive oxygen species (ROS), are involved in various pathologies, injuries related to radiation, ischemia-reperfusion or ageing. Unfortunately, it is virtually impossible to directly detect free radicals in vivo, but the redox status of the whole organism or particular organ can be studied in vivo by using magnetic resonance techniques (EPR and MRI) and paramagnetic stable free radicals - nitroxides. Here we review results obtained in vivo following the pharmacokinetics of nitroxides on experimental animals (and a few in humans) under various conditions. The focus was on conditions where the redox status has been altered by induced diseases or harmful agents, clearly demonstrating that various EPR/MRI/nitroxide combinations can reliably detect metabolically induced changes in the redox status of organs. These findings can improve our understanding of oxidative stress and provide a basis for studying the effectiveness of interventions aimed to modulate oxidative stress. Also, we anticipate that the in vivo EPR/MRI approach in studying the redox status can play a vital role in the clinical management of various pathologies in the years to come providing the development of adequate equipment and probes.
Collapse
Affiliation(s)
- Goran Bačić
- EPR Laboratory, Faculty of Physical Chemistry, University of Belgrade, 11000 Belgrade, Serbia
| | - Aleksandra Pavićević
- EPR Laboratory, Faculty of Physical Chemistry, University of Belgrade, 11000 Belgrade, Serbia
| | - Fabienne Peyrot
- LCBPT, UMR 8601 CNRS - Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France; ESPE of Paris, Paris Sorbonne Université, 75016 Paris, France
| |
Collapse
|
12
|
Marucco A, Carella E, Fenoglio I. A comparative study on the efficacy of different probes to predict the photo-activity of nano-titanium dioxide toward biomolecules. RSC Adv 2015. [DOI: 10.1039/c5ra14303a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A systematic study has been performed to select cell-free tests able to predict the photo-activity of nano-TiO2 in living organisms.
Collapse
Affiliation(s)
- A. Marucco
- Dip. Chimica
- “G. Scansetti” Interdepartmental Centre for Studies on Asbestos and Other Toxic Particulates
- NIS – Nanostructured Interfaces and Surfaces
- University of Torino
- Italy
| | - E. Carella
- Dip. Chimica
- “G. Scansetti” Interdepartmental Centre for Studies on Asbestos and Other Toxic Particulates
- NIS – Nanostructured Interfaces and Surfaces
- University of Torino
- Italy
| | - I. Fenoglio
- Dip. Chimica
- “G. Scansetti” Interdepartmental Centre for Studies on Asbestos and Other Toxic Particulates
- NIS – Nanostructured Interfaces and Surfaces
- University of Torino
- Italy
| |
Collapse
|
13
|
Abstract
Neuroinflammation plays a central role in a variety of neurological diseases, including stroke, multiple sclerosis, Alzheimer’s disease, and malignant CNS neoplasms, among many other. Different cell types and molecular mediators participate in a cascade of events in the brain that is ultimately aimed at control, regeneration and repair, but leads to damage of brain tissue under pathological conditions. Non-invasive molecular imaging of key players in the inflammation cascade holds promise for identification and quantification of the disease process before it is too late for effective therapeutic intervention. In this review, we focus on molecular imaging techniques that target inflammatory cells and molecules that are of interest in neuroinflammation, especially those with high translational potential. Over the past decade, a plethora of molecular imaging agents have been developed and tested in animal models of (neuro)inflammation, and a few have been translated from bench to bedside. The most promising imaging techniques to visualize neuroinflammation include MRI, positron emission tomography (PET), single photon emission computed tomography (SPECT), and optical imaging methods. These techniques enable us to image adhesion molecules to visualize endothelial cell activation, assess leukocyte functions such as oxidative stress, granule release, and phagocytosis, and label a variety of inflammatory cells for cell tracking experiments. In addition, several cell types and their activation can be specifically targeted in vivo, and consequences of neuroinflammation such as neuronal death and demyelination can be quantified. As we continue to make progress in utilizing molecular imaging technology to study and understand neuroinflammation, increasing efforts and investment should be made to bring more of these novel imaging agents from the “bench to bedside.”
Collapse
Affiliation(s)
- Benjamin Pulli
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| | - John W Chen
- Center for Systems Biology and Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| |
Collapse
|
14
|
Utsumi H. Novel Redox Molecular Imaging “ReMI” with Dual Magnetic Resonance. YAKUGAKU ZASSHI 2013; 133:803-14. [DOI: 10.1248/yakushi.13-00139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hideo Utsumi
- Innovation Center for Medical Redox Navigation, Kyushu University
| |
Collapse
|
15
|
Ichikawa K, Yasukawa K. Imagingin vivoredox status in high spatial resolution with OMRI. Free Radic Res 2012; 46:1004-10. [DOI: 10.3109/10715762.2012.670874] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
16
|
Elas M, Ichikawa K, Halpern HJ. Oxidative stress imaging in live animals with techniques based on electron paramagnetic resonance. Radiat Res 2012; 177:514-23. [PMID: 22348251 DOI: 10.1667/rr2668.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Oxidative stress has been the object of considerable biological and biochemical investigation. Quantification has been difficult although the quantitative level of products of biological oxidations in tissues and tissue products has emerged as a widely used technique. The relationship between these products and the amount of oxidative stress is less clear. Imaging oxidative stress with electron paramagnetic resonance related magnetic resonance imaging, while not addressing the specific issue of quantification of initiating events, focuses on the anatomic specific location of the oxidative stress. Moreover, the relative quantification of oxidative stress of one location against another is possible, sharpening our understanding of oxidative stress. This promises to improve our understanding of oxidative stress and its deleterious consequences and enhance our understanding of the effectiveness of interventions to modulate oxidative stress and its consequences.
Collapse
Affiliation(s)
- Martyna Elas
- Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
| | | | | |
Collapse
|
17
|
Ueda A, Hirayama A, Nagase S, Inoue M, Oteki T, Aoyama M, Yokoyama H. In vivodetection of intrinsic reactive oxygen species using acyl-protected hydroxylamine in puromycin nephrosis. Free Radic Res 2009; 41:823-8. [PMID: 17577743 DOI: 10.1080/10715760701411161] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Intrinsic reactive oxygen species (ROS) in a rat model of human minimal change nephropathy were detected directly using an in vivo electron paramagnetic resonance (EPR) method with 1-acetoxy-3-carbamoyl-2,2,5,5-tetramethylpyrrolidine (ACP) in real time. The nephrosis was induced by the intravenous administration of 75 mg/kg of puromycin aminonucleoside (PAN). It was found that ROS in the kidney were increased 1 h after the administration of PAN. This increased oxidative stress declined at 24 h and returned to a normal level 3 days after PAN administration. This is the first non-invasive in vivo detection and quantification of specific ROS in an experimental nephrosis model.
Collapse
Affiliation(s)
- Atsushi Ueda
- Department of Internal Medicine, Namegata District General Hospital, Ibaraki, Japan
| | | | | | | | | | | | | |
Collapse
|
18
|
ICHIKAWA K, YAMADA KI, YASUKAWA K, UTSUMI H. Analysis of In vivo Redox Status with Magnetic Resonance Technique. YAKUGAKU ZASSHI 2009; 129:273-8. [DOI: 10.1248/yakushi.129.273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kazuhiro ICHIKAWA
- Department of Bio-function Science, Faculty of Pharmaceutical Sciences, Kyushu University
| | - Ken-ichi YAMADA
- Department of Bio-function Science, Faculty of Pharmaceutical Sciences, Kyushu University
| | - Keiji YASUKAWA
- Department of Bio-function Science, Faculty of Pharmaceutical Sciences, Kyushu University
| | - Hideo UTSUMI
- Department of Bio-function Science, Faculty of Pharmaceutical Sciences, Kyushu University
| |
Collapse
|
19
|
Yan G, Peng L, Jian S, Li L, Bottle SE. Spin probes for electron paramagnetic resonance imaging. Sci Bull (Beijing) 2008. [DOI: 10.1007/s11434-008-0520-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
20
|
Serrander L, Cartier L, Bedard K, Banfi B, Lardy B, Plastre O, Sienkiewicz A, Fórró L, Schlegel W, Krause KH. NOX4 activity is determined by mRNA levels and reveals a unique pattern of ROS generation. Biochem J 2007; 406:105-14. [PMID: 17501721 PMCID: PMC1948990 DOI: 10.1042/bj20061903] [Citation(s) in RCA: 503] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
NOX4 is an enigmatic member of the NOX (NADPH oxidase) family of ROS (reactive oxygen species)-generating NADPH oxidases. NOX4 has a wide tissue distribution, but the physiological function and activation mechanisms are largely unknown, and its pharmacology is poorly understood. We have generated cell lines expressing NOX4 upon tetracycline induction. Tetracycline induced a rapid increase in NOX4 mRNA (1 h) followed closely (2 h) by a release of ROS. Upon tetracycline withdrawal, NOX4 mRNA levels and ROS release decreased rapidly (<24 h). In membrane preparations, NOX4 activity was selective for NADPH over NADH and did not require the addition of cytosol. The pharmacological profile of NOX4 was distinct from other NOX isoforms: DPI (diphenyleneiodonium chloride) and thioridazine inhibited the enzyme efficiently, whereas apocynin and gliotoxin did not (IC(50)>100 muM). The pattern of NOX4-dependent ROS generation was unique: (i) ROS release upon NOX4 induction was spontaneous without need for a stimulus, and (ii) the type of ROS released from NOX4-expressing cells was H(2)O(2), whereas superoxide (O(2)(-)) was almost undetectable. Probes that allow detection of intracellular O(2)(-) generation yielded differential results: DHE (dihydroethidium) fluorescence and ACP (1-acetoxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine) ESR measurements did not detect any NOX4 signal, whereas a robust signal was observed with NBT. Thus NOX4 probably generates O(2)(-) within an intracellular compartment that is accessible to NBT (Nitro Blue Tetrazolium), but not to DHE or ACP. In conclusion, NOX4 has a distinct pharmacology and pattern of ROS generation. The close correlation between NOX4 mRNA and ROS generation might hint towards a function as an inducible NOX isoform.
Collapse
Affiliation(s)
- Lena Serrander
- Foundation for Medical Research, University of Geneva, 64 av de la Roseraie, 1205, Geneva, Switzerland.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
Brain function depends exquisitely on oxygen for energy metabolism. Measurements of brain tissue oxygen tension, by a variety of quantitative and qualitative techniques, going back for >50 years, have led to a number of significant conclusions. These conclusions have important consequences for understanding brain physiology as it is now being explored by techniques such as blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD fMRI) and near-infrared spectroscopy (NIRS). It has been known for some time that most of the measured oxygen tensions are less than venous pO2 and are distributed in a spatially and temporally heterogeneous manner on a microregional scale. Although certain large-scale methods can provide reproducible average brain pO2 measurements, no useful concept of a characteristic oxygen tension or meaningful average value for brain tissue oxygen can be known on a microregional level. Only an oxygen field exists with large local gradients due to local tissue respiration, and the most useful way to express this is with a pO2 distribution curve or histogram. The neurons of the brain cortex normally exist in a low-oxygen environment and on activation are oxygenated by increases in local capillary blood flow that lead to increases in hemoglobin saturation and tissue oxygen.
Collapse
Affiliation(s)
- Obinna Ndubuizu
- Department of Physiology and Anatomy, Case Western Reserve University, Cleveland, Ohio 44106-4930, USA
| | | |
Collapse
|
22
|
Affiliation(s)
- Stephen A Hitchcock
- Chemistry Research & Discovery, Amgen, One Amgen Center Drive, Thousand Oaks, CA 91320-1799, USA.
| | | |
Collapse
|
23
|
Bobko AA, Kirilyuk IA, Grigor'ev IA, Zweier JL, Khramtsov VV. Reversible reduction of nitroxides to hydroxylamines: roles for ascorbate and glutathione. Free Radic Biol Med 2007; 42:404-12. [PMID: 17210453 PMCID: PMC1829321 DOI: 10.1016/j.freeradbiomed.2006.11.007] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Revised: 10/24/2006] [Accepted: 11/06/2006] [Indexed: 11/21/2022]
Abstract
Biological applications of stable nitroxyl radicals, NR, include their use as contrast agents for magnetic resonance imaging, spin labels, superoxide dismutase mimics, and antioxidants. The rapid reduction of NR in biological samples into hydroxylamines (HA) significantly limits their application. In turn, reoxidation of HA back to the NR has been used for detection of reactive oxygen species (ROS). In this work comparative studies of the reduction of pyrrolidine, imidazoline, and imidazolidine NR by ascorbate were performed taking advantage of recently synthesized tetraethyl-substituted NR with much higher stability toward reduction both in vitro and in vivo. Surprisingly, these NR kept 10-50% of initial intensity of electron paramagnetic resonance signal for about 1 h in the presence of 100-fold excess of ascorbate. To explain these data, reoxidation of the corresponding HA by ascorbate radical and dehydroascorbic acid back to the NR was proposed. This hypothesis was supported by direct measurement of the NR appearance from the HA on ascorbate radical generation by ascorbate oxidase, or in the presence of the dehydroascorbic acid. The reversible reaction between NR and ascorbate was observed for the various types of NR, and the rate constants for direct and reverse reactions were determined. The equilibrium constants for one-electron reduction of the tetraethyl-substituted NR by ascorbate were found to be in the range from 2.65x10(-6) to 10(-5) which is significantly lower than corresponding values for the tetramethyl-substituted NR (more or about 10(-4)). This explains the establishment of an EPR-detectable quasi-equilibrium level of tetraethyl-substituted NR in the presence of an excess of ascorbate. The redox reactions of the NR-HA couple in ascorbate-containing media were found to be significantly affected by glutathione (GSH). This effect was attributed to the reduction of ascorbate radicals by GSH, and the rate constant of this reaction was found to be equal to 10 M-1 s-1. In summary, the data provide new insight into the redox chemistry of NR and HA, and significantly affect interpretation and strategy of their use as redox- and ROS-sensitive probes, or as antioxidants.
Collapse
Affiliation(s)
- Andrey A Bobko
- Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
| | | | | | | | | |
Collapse
|
24
|
Manda S, Nakanishi I, Ohkubo K, Yakumaru H, Matsumoto KI, Ozawa T, Ikota N, Fukuzumi S, Anzai K. Nitroxyl radicals: electrochemical redox behaviour and structure–activity relationships. Org Biomol Chem 2007; 5:3951-5. [DOI: 10.1039/b714765a] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
25
|
Sato S, Nemoto M, Kumazawa T, Matsuba S, Onodera JI, Aoyama M, Obara H, Kamada H. Synthesis and enzyme-catalyzed hydrolysis of a radical-masked glycosylated spin-label reagent. Carbohydr Res 2005; 339:2425-32. [PMID: 15388357 DOI: 10.1016/j.carres.2004.07.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Accepted: 07/14/2004] [Indexed: 11/24/2022]
Abstract
N1-Acetoxy-2,2,6,6-tetramethylpiperidin-4-yl 2,3,4,6-tetra-O-benzyl-alpha- and -beta-D-glucopyranosides (3-alpha, beta) and N1-acetoxy-2,2,5,5-tetramethylpyrrolin-3-oyl 2,3,4,6-tetra-O-benzyl-alpha- and -beta-D-glucopyranosylamines (9-alpha, beta) were synthesized in good yield by Schmidt's glycosylation method. Their subsequent O-debenzylation was proceeded successfully to give the desired products 1-alpha, and 1-beta in good yield, and 2-alpha in a low yield, without 2-beta by only short-timed hydrogenolysis in the presence of palladium-on-carbon (Pd-C) in a CHCl3-MeOH solvent system that included concentrated HCl. Upon enzyme-catalyzed hydrolysis, only 2-alpha was hydrolyzed by the esterase, while both of 1-alpha and 1-beta were not hydrolyzed by any other enzyme such as lipase. These 2-alpha can likely be used as a new water-soluble radical-masked glycosylated spin-label reagent.
Collapse
Affiliation(s)
- Shingo Sato
- Department of Chemistry and Chemical Engineering, Faculty of Engineering, Yamagata University, 4-3-16 Jonan, Yamagata, Yonezawa 992-8510, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Takeshita K, Ozawa T. Recent progress in in vivo ESR spectroscopy. JOURNAL OF RADIATION RESEARCH 2004; 45:373-384. [PMID: 15613782 DOI: 10.1269/jrr.45.373] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The generation of free radicals and redox status is related to various diseases and injuries that are related to radiation, aging, ischemia-reperfusion, and other oxidative factors. In vivo electron spin resonance (ESR) spectroscopy is noninvasive and detects durable free radicals in live animals. ESR spectrometers for in vivo measurements operate at a lower frequency (approximately 3.5 GHz, approximately 1 GHz, 700 MHz, and approximately 300 MHz) than usual (9-10 GHz). Several types of resonators have been designed to minimize the dielectric loss of electromagnetic waves caused by water in animal bodies. In vivo ESR spectroscopy and its imaging have been used to analyze radical generation, redox status, partial pressure of oxygen and other conditions in various disease and injury models related to oxidative stress with probes, such as nitroxyl radicals. Through these applications, the clarification of the mechanisms related to oxidative diseases (injuries) and the accumulation of basic data for radiological cancer therapy are now ongoing. In vivo ESR measurement is performed in about 10 laboratories worldwide, including ours. To introduce in vivo ESR spectroscopy to life scientists, this article reviews the recent progress of in vivo ESR spectroscopy in instrumentation and its application to the life sciences.
Collapse
Affiliation(s)
- Keizo Takeshita
- Redox Regulation Research Group, National Institute of Radiological Sciences, Chiba, Japan.
| | | |
Collapse
|
27
|
Saito K, Takeshita K, Anzai K, Ozawa T. Pharmacokinetic study of acyl-protected hydroxylamine probe, 1-acetoxy-3-carbamoyl-2,2,5,5-tetramethylpyrrolidine, for in vivo measurements of reactive oxygen species. Free Radic Biol Med 2004; 36:517-25. [PMID: 14975454 DOI: 10.1016/j.freeradbiomed.2003.11.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2003] [Revised: 10/29/2003] [Accepted: 11/14/2003] [Indexed: 11/22/2022]
Abstract
1-Acetoxy-3-carbamoyl-2,2,5,5-tetramethylpyrrolidine (ACP) is a unique probe for in vivo measurements of reactive oxygen species (ROS), because it is hydrolyzed by esterase to a hydroxylamine form (CP-H), which is oxidized to an electron spin resonance-detectable nitroxyl radical (CP) by a reaction with superoxide anion radical, etc. Although a knowledge of pharmacokinetics is essential for the use of ACP in vivo, such information is limited. We investigated the pharmacokinetics of ACP in mice by examining the time course of the tissue distribution of ACP, CP-H, and CP after intravenous or intraperitoneal injection of ACP. Esterase activity for ACP in tissue homogenates was also measured. The concentration of ACP decreased in all tissues obeying a one-compartment model. ACP was hydrolyzed to CP-H in the liver and kidney predominantly, and the first-pass effect of liver on the hydrolysis of ACP was very large. A homogeneous biodistribution of CP-H was obtained 10 min after the injection of ACP regardless of the injection route, and concentrations remained stable over at least 20 min. Because of these pharmacokinetic properties, ACP should be suitable for the imaging of ROS in animals.
Collapse
Affiliation(s)
- Keita Saito
- Redox Regulation Research Group, National Institute of Radiological Sciences, 9-1, Anagawa-4, Inage-ku, Chiba 263-8555, Japan
| | | | | | | |
Collapse
|
28
|
Yordanov AT, Yamada KI, Krishna MC, Russo A, Yoo J, English S, Mitchell JB, Brechbiel MW. Acyl-protected hydroxylamines as spin label generators for EPR brain imaging. J Med Chem 2002; 45:2283-8. [PMID: 12014966 DOI: 10.1021/jm0105169] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In a search for novel electron paramagnetic resonance (EPR) brain imaging agents, we have designed and synthesized the acyl-protected hydroxylamines 1-acetoxy-4-methoxycarbonyl-2,2,6,6-tetramethylpiperidine (AMCPe), 1-acetoxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine (AMCPy), and 1-acetoxy-3-(acetoxymethoxy)carbonyl-2,2,5,5-tetramethylpyrrolidine (DACPy), in which both the ring size and the number of ester functions were varied. In all of them, the nitroxide was first reduced and the resultant hydroxylamine was then protected with an acetyl group. These compounds are lipophilic, which is a major prerequisite for blood-brain barrier penetration. Once in the brain, esterases and oxidants quickly convert these derivatives into ionic, water-soluble radicals and thus EPR detectable species that then reside in the central nervous system for periods of time sufficient for detection and imaging. The biological relevancy of these new compounds in mice has been assessed, and their biodistribution patterns have been compared. The five-membered ring derivative AMCPy emerged as a potent EPR brain imaging agent while the other two derivatives, AMCPe and DACPy, were quite ineffective.
Collapse
Affiliation(s)
- Alexander T Yordanov
- Radioimmune & Inorganic Chemistry Section, Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Wennerberg AB, Jonsson T, Forssberg H, Li TQ. Current awareness in NMR in biomedicine. NMR IN BIOMEDICINE 2001; 14:48-53. [PMID: 11252040 DOI: 10.1002/nbm.667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of NMR in biomedicine. Each bibliography is divided into 9 sections: 1 Books, Reviews ' Symposia; 2 General; 3 Technology; 4 Brain and Nerves; 5 Neuropathology; 6 Cancer; 7 Cardiac, Vascular and Respiratory Systems; 8 Liver, Kidney and Other Organs; 9 Muscle and Orthopaedic. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.
Collapse
Affiliation(s)
- A B Wennerberg
- Department of KARO, Division of Diagnostic Radiology, Karolinska Institutet, Huddinge University Hospital, SE-141 86 Stockholm, Sweden
| | | | | | | |
Collapse
|