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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.
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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
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Uchida T, Togashi H, Kuroda Y, Haga K, Sadahiro M, Kayama T. In vivo visualization of redox status by high-resolution whole body magnetic resonance imaging using nitroxide radicals. J Clin Biochem Nutr 2018; 63:192-196. [PMID: 30487668 PMCID: PMC6252305 DOI: 10.3164/jcbn.18-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/13/2018] [Indexed: 11/30/2022] Open
Abstract
Various diseases are known to be associated with an imbalance of the redox state, but in vivo detection of free radicals is difficult. The purpose of this study is to establish a method for in vivo visualization of redox status by high-resolution whole-body MRI using nitroxide radicals. A redox-sensitive nitroxide probe, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (carbamoyl-PROXYL), was administered to rats intravenously, and in vivo T1-weighted MRI was performed to virtually visualize the redox status of various organs. In experiments using phantoms, a linear relationship between the MRI signal and the carbamoyl-PROXYL concentration persisted up to 80 mM. Among the phantoms, a sample containing 1 mM carbamoyl-PROXYL was readily identifiable. After intravenous injection of carbamoyl-PROXYL, whole-body T1-weighted MRI of the rat provided clear images with good spatial and temporal resolution. The signal intensities of four selected organs (heart, liver, kidney, and intestine) were analyzed quantitatively. The carbamoyl-PROXYL signal peaked and gradually declined due to reduction after intravenous injection. Among the four organs, the organ-specific reduction rate of carbamoyl-PROXYL was highest in the heart, followed by (in order) the liver, kidney, and intestine, and statistical analysis showed that the inter-organ differences were significant. In conclusion, T1-weighted carbamoyl-PROXYL-enhanced MRI provides excellent spatial and temporal imaging of carbamoyl-PROXYL distribution. Furthermore, it provides important functional information pertaining to blood flow and tissue redox activity in individual organs. MRI in combination with carbamoyl-PROXYL has potential clinical application for evaluation of redox activity in whole organs.
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Affiliation(s)
- Tetsuro Uchida
- Second Department of Surgery, Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
| | - Hitoshi Togashi
- Health Administration Center, Yamagata University, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
| | - Yoshinori Kuroda
- Second Department of Surgery, Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
| | - Kazuyuki Haga
- Radiation Department, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
| | - Mitsuaki Sadahiro
- Second Department of Surgery, Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
| | - Takamasa Kayama
- Department of Advanced Cancer Science, Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan
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Togashi H, Aoyama M, Oikawa K. Imaging of reactive oxygen species generated in vivo. Magn Reson Med 2015; 75:1375-9. [PMID: 25885107 DOI: 10.1002/mrm.25582] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 10/18/2014] [Accepted: 11/21/2014] [Indexed: 11/10/2022]
Abstract
PURPOSE We sought to image the biodistribution of reactive oxygen species (ROS) within the living body using an in vivo electron spin resonance (ESR) imaging system using a spin probe, 1-acetoxy-3-carbamoyl-2,2,5,5-tetramethylpyrroline (ACP) that produces ESR-detectable nitroxide upon reaction with ROS. METHODS Acute hepatic injury was induced in mice by priming with heat-killed Corynebacterium parvum followed by injection of a low dose of lipopolysaccharide. ACP was administered intravenously and an in vivo ESR imaging system was used to visualize hepatic oxidative stress. RESULTS In this immune-mediated hepatic injury model, significant oxidative stress was evident at 3 h after lipopolysaccharide administration before the onset of massive hepatic injury. ACP was administered intravenously at 3 h after lipopolysaccharide injection when significant hepatic oxidative stress had been observed, and the ESR imaging system detected a high signal for 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine (carbamoyl-PROXYL), which had originated from the ACP-derived hydroxylamine and produced large amount of ROS within the living body. Using the ESR imaging system with ACP, we were able to visualize ROS in the abdomen before onset of hepatic injury. CONCLUSION We have succeeded in visualizing ROS within the body before onset of organ damage, representing a significant development in imaging for toxic molecules.
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Affiliation(s)
- Hitoshi Togashi
- Yamagata University Health Administration Center, Yamagata, Japan
| | - Masaaki Aoyama
- Institute for Life Support Technology, Yamagata Public Corporation for Development of Industry, Yamagata, Japan
| | - Kazuo Oikawa
- Yamagata Research Institute of Technology, Yamagata, Japan
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Tomizawa A, Hadjidekov G, Ishii I, Bakalova R, Zhelev Z, Aoki I, Saga T, Kitada M. Nitroxide derivatives for imaging of hypercholesterolemia-induced kidney dysfunction and assessing the effectiveness of antilipidemic drugs. Mol Pharm 2011; 8:1962-9. [PMID: 21744874 DOI: 10.1021/mp200087v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The present study was designed to clarify the possibility for application of nitroxide derivatives in magnetic resonance imaging (MRI) of hypercholesterolemia-mediated renal dysfunction in mice, as well as to assess the effectiveness of antilipidemic drugs (cholestyramine and ezetimibe). The mice were separated in four groups: (i) on a normal diet (ND) without medication (control); (ii) on a high cholesterol diet (CD) without medication; (iii) CD mice receiving cholestyramine; and (iv) CD mice receiving ezetimibe. In CD mice without medication, a hypercholesterolemia was developed, detected by the increasing of total plasma cholesterol and non-HDL cholesterol, and decreasing of HDL cholesterol. The hypercholesterolemia compromised renal function: blood urea nitrogen, creatine and uric acid increased significantly, accompanied with development of glomerulosclerosis, enhancement of the amount of neutrophils and overexpression of metalloproteinase-9. The mice were subjected to anesthesia and MR imaging was performed on 7 T magnet (T1-weighted incoherent gradient-echo sequence; fast low-angle shot). The region-of-interest was selected within the kidney. The images were obtained before and after injection of contrast probe [carbamoyl-PROXYL (CMP) or Gd-DTPA]. In the kidney of ND mice, the MRI signal intensity increased after injection of CMP, reached a maximum (very well-defined renal filtration peak) and decreased to the baseline level within 14 min. In kidney of CD mice, the CMP-mediated enhancement of MRI signal was not detected. Antilipidemic drugs patially abolished the effect of hypercholesterolemia on CMP-enhanced MRI in the kidney. The kinetic curves of Gd-enhanced MRI signal had also different profiles in the kidney of ND and CD mice. They were similar to the profiles of the kinetic curves, obtained from MR urography of healthy human and human with renal pathology, respectively. The present study suggests that CMP is a suitable MRI contrast probe for visualization of hypercholesterolemia-induced renal dysfunction in intact animals and the assessment of the efficacy of antilipidemic drugs. The probe was applied at a concentration that was 3 times lower than the LD50 for intravenous administration in mice. Since the probe is excreted by the kidney, it could be considered harmless for mammalians in the selected dose and appropriate candidate for translational research.
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Affiliation(s)
- Atsuyuki Tomizawa
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
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Ito S, Mori T, Kanazawa H, Sawaguchi T. Estimation of the postmortem duration of mouse tissue by electron spin resonance spectroscopy. J Toxicol 2011; 2011:973172. [PMID: 21776268 PMCID: PMC3135332 DOI: 10.1155/2011/973172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/29/2011] [Accepted: 04/12/2011] [Indexed: 11/25/2022] Open
Abstract
Electron spin resonance (ESR) method is a simple method for detecting various free radicals simultaneously and directly. However, ESR spin trap method is unsuited to analyze weak ESR signals in organs because of water-induced dielectric loss (WIDL). To minimize WIDL occurring in biotissues and to improve detection sensitivity to free radicals in tissues, ESR cuvette was modified and used with 5,5-dimethtyl-1-pyrroline N-oxide (DMPO). The tissue samples were mouse brain, hart, lung, liver, kidney, pancreas, muscle, skin, and whole blood, where various ESR spin adduct signals including DMPO-ascorbyl radical (AsA(∗)), DMPO-superoxide anion radical (OOH), and DMPO-hydrogen radical (H) signal were detected. Postmortem changes in DMPO-AsA(∗) and DMPO-OOH were observed in various tissues of mouse. The signal peak of spin adduct was monitored until the 205th day postmortem. DMPO-AsA(∗) in liver (y = 113.8-40.7 log (day), R1 = -0.779, R2 = 0.6, P < .001) was found to linearly decrease with the logarithm of postmortem duration days. Therefore, DMPO-AsA(∗) signal may be suitable for detecting an oxidation stress tracer from tissue in comparison with other spin adduct signal on ESR spin trap method.
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Affiliation(s)
- Shinobu Ito
- I.T.O. Provitamin Research Center, 1-6-7-3F Nakamachi, Musashino, Tokyo, Japan
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan
| | - Tomohisa Mori
- Department of Pharmacology and Experimental Neuroscience, College of Medicine, University of Nebraska at Omaha, Omaha, NE 68182, USA
| | - Hideko Kanazawa
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan
| | - Toshiko Sawaguchi
- Department of Occupational Therapy, Faculty of Regional Health Therapy, Teikyo Heisei University, 4-1 Uruido-minami, Ichihara, Chiba, Japan
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Quine RW, Czechowski T, Eaton GR. A Linear Magnetic Field Scan Driver. CONCEPTS IN MAGNETIC RESONANCE. PART B, MAGNETIC RESONANCE ENGINEERING 2009; 35B:44-58. [PMID: 19838315 PMCID: PMC2762224 DOI: 10.1002/cmr.b.20128] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A linear magnetic field scan driver was developed to provide a rapidly scanning magnetic field for use in electron paramagnetic resonance (EPR) spectroscopy. The driver consists of two parts: a digitally synthesized ramp waveform generator and a power amplifier to drive the magnetic field coils. Additionally, the driver provides a trigger signal to a data collection digitizer that is synchronized to the ramp waveform. The driver can also drive an arbitrary current waveform supplied from an external source. The waveform generator is computer controlled through a serial data interface. Additional functions are controlled by the user from the driver front panel. The frequency and amplitude of the waveform are each separately controlled with 12-bit resolution (one part in 4,096). Several versions of the driver have been built with different frequency and amplitude ranges. Frequencies range from 500 to 20,000 Hz. Field sweep amplitudes range up to 80 G(pp). This article also gives a brief description of the field coils that are driven by the driver.
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Affiliation(s)
- Richard W Quine
- Department of Engineering, University of Denver, Denver, CO 80208
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Hirayama A, Ueda A, Oteki T, Nagase S, Aoyagi K, Koyama A. In vivo imaging of renal redox status during azelnidipine treatment. Hypertens Res 2008; 31:1643-50. [PMID: 18971540 DOI: 10.1291/hypres.31.1643] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The effect of the calcium channel blocker azelnidipine on the redox status of a murine hypertension model was analyzed and imaged using in vivo low frequency electron paramagnetic resonance (EPR). A murine two kidney-one clip (2K1C) hypertension model was produced by a clipping of the right renal artery. The resulting hypertensive mice were treated with low-dose azelnidipine (1 mg/kg/d), with high-dose azelnidipine (3 mg/kg/d) or without azelnidipine (HT group). An EPR system equipped with a loop-gap resonator and an imaging system was employed. Redox status was evaluated as organ reducing activity measured by means of the decay rate (half-lives) of the spin probe 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (Carbamoyl-PROXYL). Four weeks after clipping the mice demonstrated hypertension as expected. After the additional 2 weeks of azelnidipine treatments, the Carbamoyl-PROXYL half-lives of the Low and High azelnidipine groups measured in the upper abdominal area were significantly shorter than those of the HT group, suggesting improvements in the reducing activity. The blood pressures of the three groups showed no significant differences at this time, and there was no correlation between the renal reducing activity and either blood pressure or serum creatinine values. EPR imaging studies revealed that the improvement in abdominal reducing activity was mainly recognized in the kidney but not in the liver. These results indicate that azelnidipine ameliorates renal redox status through an improvement in reducing activity independent of blood pressure control.
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Affiliation(s)
- Aki Hirayama
- Center for Integrative Medicine, Tsukuba University of Technology, Tsukuba, Japan.
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Watanabe T, Oowada S, Kobayashi HP, Kamibayashi M, Ishiuchi A, Jinnouchi Y, Koizumi S, Asano T, Shimamura T, Asakura T, Nakano H, Kubota S, Otsubo T. The Role of the New Ca2+ Antagonist, CV159, in Hepatic I/R Injury—The Evaluation of Hepatic Organ Reducing Activity Using In Vivo and Ex Vivo EPR. J Surg Res 2008; 145:49-56. [DOI: 10.1016/j.jss.2006.12.559] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Revised: 12/19/2006] [Accepted: 12/21/2006] [Indexed: 10/22/2022]
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Hirayama A, Nagase S. Electron paramagnetic resonance imaging of oxidative stress in renal disease. Nephron Clin Pract 2006; 103:c71-6. [PMID: 16543759 DOI: 10.1159/000090612] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The importance of analyzing the kinetics of reactive oxygen species or related substances in vivo is increasing. Electron paramagnetic resonance (EPR) is currently a powerful method for in vivo, non-invasive analysis of oxidative stress. We have applied EPR imaging for murine renal ischemia-reperfusion injury, as a model of acute renal damage, and NF-E2-related factor 2 (Nrf2)-deficient mice, a model for chronic progressive renal disease. In the ischemia-reperfusion model, EPR imaging revealed that the renal radical-reducing activity showed only partial recovery when serum creatinine and BUN have recovered. In the Nrf2-deficient mice, we have revealed that the impaired antioxidant activity is brought by both Nrf2 deficiency and the aging process and may play a key role in the onset of autoimmune nephritis in this model. In addition, EPR imaging is recently being applied to the redox analysis of several nephrosis models, hypertensive rats and streptozotocin-induced diabetic rats. This article summarizes the nephrological application of EPR imaging and in vivo EPR.
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Affiliation(s)
- Aki Hirayama
- Department of Nephrology, Medical Sciences for Control of Pathological Processes, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan.
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Uwayama J, Hirayama A, Yanagawa T, Warabi E, Sugimoto R, Itoh K, Yamamoto M, Yoshida H, Koyama A, Ishii T. Tissue Prx I in the protection against Fe-NTA and the reduction of nitroxyl radicals. Biochem Biophys Res Commun 2005; 339:226-31. [PMID: 16297875 DOI: 10.1016/j.bbrc.2005.10.192] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Accepted: 10/28/2005] [Indexed: 11/25/2022]
Abstract
Peroxiredoxin I (Prx I) is a key cytoplasmic peroxidase that reduces intracellular hydroperoxides in concert with thioredoxin. To study the role of tissue Prx I in protection from oxidative stress, we generated Prx I-/- mice by gene trapping. We then evaluated the acute-phase tissue damage caused by ferric-nitrilotriacetate (Fe-NTA). Increases in serum aspartate aminotransferase and alanine aminotransferase levels were significantly greater in Prx I-/- than wild-type mice, 4 and 12 h after the injection of Fe-NTA. Using real-time EPR imaging, we examined the reduction of the stable paramagnetic nitroxyl radical 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl in vivo, and found that the half-life of this spin probe in the liver and kidney was significantly prolonged in the Prx I-/- mice. These results demonstrate that Prx I-/- mice have less reducing activity and are more susceptible to the damage mediated by reactive oxygen species in vivo than wild-type mice.
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Affiliation(s)
- Junya Uwayama
- Biomolecular and Integrated Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
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Rohn S, Kroh LW. Electron spin resonance - A spectroscopic method for determining the antioxidative activity. Mol Nutr Food Res 2005; 49:898-907. [PMID: 15945117 DOI: 10.1002/mnfr.200400102] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sascha Rohn
- Institute of Food Technology and Food Chemistry, Department of Food Analysis, Technical University of Berlin, Gustav-Meyer-Allee 25, D-13355 Berlin, Germany.
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Yoshida M, Saegusa Y, Fukuda A, Akama Y, Owada S. Measurement of radical-scavenging ability in hepatic metallothionein of rat using in vivo electron spin resonance spectroscopy. Toxicology 2005; 213:74-80. [PMID: 15993999 DOI: 10.1016/j.tox.2005.05.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2005] [Accepted: 05/16/2005] [Indexed: 11/21/2022]
Abstract
In this study, the ability of metallothionein (MT) to scavenge free radicals was determined by in vivo electron spin resonance (ESR) spectroscopy using a carbamoyl-PROXYL, nitroxyl radical, as a spin probe. Production of metallothionein was induced in the liver of rats with ZnSO(4) (0.2 mol/kg, ip) and the intensity of the carbamoyl-PROXYL ESR signal was measured at the upper abdominal level which is a position of the liver. After the injection of carbamoyl-PROXYL, the peak of ESR signal gradually decreased and showed a linear decay curve. The rate of decay of carbamoyl-PROXYL, the spin clearance rate, was determined over the first 3 min. The spin clearance rate did not differ significantly between ZnSO(4)-treated and control rats. When rats were fasted for 24 h, hepatic glutathione (GSH) concentrations decreased significantly and the spin clearance rate was significantly lower than non-fasted rats. However, the spin clearance rate of the fasted rats treated with Zn returned to the control level. To reduce GSH concentrations in the liver, buthionine sulfoximine (BSO, 2 mmol/kg, ip) was injected into the rats. The spin clearance rate of rats treated with BSO was significantly decreased as compared with that of control rats without BSO treatment. In rats treated with Zn, the decay rate of carbamoyl-PROXYL increased significantly in spite of the depletion of the hepatic GSH caused by BSO treatment, and returned to the control level. These results indicate that when the hepatic GSH concentration was significantly decreased by fasting and the administration of BSO, hepatic MT acted as a scavenger of free radicals. We suggest that GSH and MT act cooperatively as antioxidants to scavenge free radicals produced in response to various forms of stress, and MT serves as a second rather than the first line of defense.
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Affiliation(s)
- Minoru Yoshida
- Department of Biochemistry, Division of Chemistry, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki 261-8511, Japan.
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Hirayama A, Nagase S, Ueda A, Oteki T, Takada K, Obara M, Inoue M, Yoh K, Hirayama K, Koyama A. In vivo imaging of oxidative stress in ischemia-reperfusion renal injury using electron paramagnetic resonance. Am J Physiol Renal Physiol 2005; 288:F597-603. [PMID: 15536173 DOI: 10.1152/ajprenal.00020.2004] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Oxidative stress during ischemia-reperfusion acute renal failure (IR-ARF) was noninvasively evaluated with in vivo electron paramagnetic resonance (EPR) imaging. Female ICR mice underwent left nephrectomy and 30-min ischemia-reperfusion of the right kidney. Oxidative stress was evaluated as organ reducing activity with the half-lives of the spin probe 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (carbamoyl-PROXYL) using 1) conventional L-band EPR, which showed organ-reducing activity in the whole abdominal area; and 2) EPR imaging, which showed semiquantitative but organ-specific reducing activity. The results were compared with the reducing activity of organ homogenate and phosphatidylcholine hydroperoxide (PC-OOH) concentrations. Half-lives of carbamoyl-PROXYL in the whole upper abdominal area, measured by L-band EPR, were prolonged on day 3 after ischemia-reperfusion and recovered to the level of nontreated mice on day 7. This trend resembled closely that of serum creatinine and blood urea nitrogen concentration. The EPR imaging-measured carbamoyl-PROXYL half-life was also prolonged on day 3 in both the kidney and the liver. However, in the kidney this showed only partial recovery on day 7. In the liver, this convalescence was more remarkable. The ex vivo studies of organ reducing activity and PC-OOH agreed with the results from EPRI, but not with those from L-band EPR. These results indicate that renal reducing activity shows only partial recovery on day 7 after ischemia-reperfusion, when serum creatinine and blood urea nitrogen have recovered. EPR imaging is an appropriate and useful method for the noninvasive evaluation of oxidative stress in the presence of renal injury.
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Affiliation(s)
- Aki Hirayama
- Dept. of Nephrology, Institute of Clinical Medicine, Univ. of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan 305-8575.
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Hirayama A, Yoh K, Nagase S, Ueda A, Itoh K, Morito N, Hirayama K, Takahashi S, Yamamoto M, Koyama A. EPR imaging of reducing activity in Nrf2 transcriptional factor-deficient mice. Free Radic Biol Med 2003; 34:1236-42. [PMID: 12726911 DOI: 10.1016/s0891-5849(03)00073-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Mice that lack the Nrf2 (NF-E2-related factor 2) transcription factor develop a lupus-like autoimmune nephritis. The tissue-reducing activity of Nrf2-deficient mice was evaluated using a combination of real-time EPR imaging and spin probe kinetic analysis. Substantial delay in the spin probe 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (Carbamoyl-PROXYL) disappearance in the liver and kidneys of Nrf2-deficient mice was observed by EPR imaging. The half-life of the spin probe in the upper abdominal area was prolonged in both the Nrf2-deficient mice and in aged mice. The combination of Nrf2 deficiency and aging in female mice resulted in the most prolonged half-life of disappearance, which was four times longer than that of juvenile female mice with a wild-type genotype. These results indicate that the low reducing activity in these organs is brought about by both Nrf2 deficiency and the aging process, and it may play a key role in the onset of autoimmune nephritis. This combination of the EPR imaging and half-life analysis appears to be a very powerful tool in the real-time analysis of reducing activity.
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Affiliation(s)
- Aki Hirayama
- Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
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Yamada KI, Kuppusamy P, English S, Yoo J, Irie A, Subramanian S, Mitchell JB, Krishna MC. Feasibility and assessment of non-invasive in vivo redox status using electron paramagnetic resonance imaging. Acta Radiol 2002. [PMID: 12225490 DOI: 10.1034/j.1600-0455.2002.430418.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE To test the feasibility of electron paramagnetic resonance imaging (EPRI) to provide non-invasive images of tissue redox status using redox-sensitive paramagnetic contrast agents. MATERIAL AND METHODS Nitroxide free radicals were used as paramagnetic agents and a custom-built 300 MHz EPR spectrometer/imager was used for all studies. A phantom was constructed consisting of four tubes containing equal concentrations of a nitroxide. Varying concentrations of hypoxanthine/xanthine oxidase were added to each tube and reduction of the nitroxide was monitored by EPR as a function of time. Tumor-bearing mice were intravenously infused with a nitroxide and the corresponding reduction rate was monitored on a pixel-by-pixel basis using 2D EPR of the tumor-bearing leg and normal leg serving as control. For animal studies, nitroxides were injected intravenously (1.25 mmol/kg) and EPR projections were collected every 3 min after injection using a magnetic field gradient of 2.5 G/cm. The reduction rates of signal intensity on a pixel-by-pixel basis were calculated and plotted as a redox map. Redox maps were also collected from the mice treated with diethylmaleate (DEM), which depletes tissue thiols and alters the global redox status. RESULTS Redox maps obtained from the phantoms were in agreement with the intensity change in each of the tubes where the signals were decreasing as a function of the enzymatic activity, validating the ability of EPRI to accurately access changes in nitroxide reduction. Redox imaging capability of EPR was next evaluated in vivo. EPR images of the nitroxide distribution and reduction rates in tumor-bearing leg of mice exhibited more heterogeneity than in the normal tissue. Reduction rates were found to be significantly decreased in tumors of mice treated with DEM, consistent with the depletion of thiols and the consequent alteration of the redox status. CONCLUSION Using redox-sensitive paramagnetic contrast agents, EPRI can non-invasively discriminate redox status differences between normal tissue and tumors.
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Affiliation(s)
- K-I Yamada
- Radiation Biology Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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Hecke PV. Current awareness. NMR IN BIOMEDICINE 2000; 13:314-319. [PMID: 10960923 DOI: 10.1002/1099-1492(200008)13:5<314::aid-nbm627>3.0.co;2-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [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.
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Affiliation(s)
- PV Hecke
- Katholicke Universiteit Leuven, Facultiet der Geneeskunde, Biomedische NMR Eenheid, Onderwijs en Navorsing, Gasthuisberg, B-3000 Leuven, Belgium
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