ESR imaging investigations of two‐phase systems

Herrmann, W. M.; Stößer, Reinhard; Borchert, Hans-Hubert

doi:10.1002/mrc.1999

Cited by 14 publications

(5 citation statements)

References 28 publications

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“…Representative ESR tracings in Figure 6A show the 3 characteristic Tempol spectral signals 19 in plasma samples from Tempol-treated C57 and BPH/5 mice (no signals were detected in any samples from non-treated mice, data not shown). Analysis of the Tempol-associated spectral peak heights revealed the presence of significant amounts of Tempol in the plasma that were similar in C57 and BPH/5 (6 to 7 mol/L) ( Figure 5B).…”

Section: Plasma Tempol Levels Were Comparable In C57 and Bph/5 Mice Rmentioning

confidence: 99%

Chronic Tempol Prevents Hypertension, Proteinuria, and Poor Feto-Placental Outcomes in BPH/5 Mouse Model of Preeclampsia

et al. 2008

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Abstract-Recently we described a mouse model, BPH/5, that spontaneously develops the hallmark clinical features of preeclampsia. BPH/5 exhibit impaired placentation before the onset of hypertension and proteinuria, supporting a causal role for the placenta in the pathogenesis of preeclampsia. Here we tested the hypothesis that an increase in reactive oxygen species (ROS) early in pregnancy results in placental abnormalities leading to the maternal symptoms of preeclampsia. We further hypothesized that chronic antioxidant therapy would ameliorate both feto-placental abnormalities and maternal symptoms. ROS levels measured by dihydroethidium revealed significant increases in oxidative stress in BPH/5 placentas at midgestation compared with C57 controls. This increase in ROS was correlated with reduced expression and activity of cytoplasmic superoxide dismutase in early and midgestation BPH/5 placentas. These abnormalities in placental oxidant factors occurred before the onset of maternal symptoms, suggesting a possible causal link between increased ROS and maternal and feto-placental pathology in this model. In support of this, chronic treatment of BPH/5 with the superoxide dismutase-mimetic Tempol throughout gestation significantly improved fetal growth and survival. Furthermore, Tempol ameliorated pregnancy-induced increases in blood pressure and proteinuria in BPH/5 mothers. We confirmed that Tempol radical was present in plasma, and it normalized ROS levels in all placental zones in BPH/5. These data for the first time demonstrate an important causative role for increased ROS in the placenta in the pathogenesis of preeclampsia in a model that spontaneously develops the disease. The results also strongly suggest the potential utility of antioxidant therapy in treating preeclampsia. (Hypertension. 2008;51:1058-1065.)

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Section: Plasma Tempol Levels Were Comparable In C57 and Bph/5 Mice Rmentioning

confidence: 99%

Chronic Tempol Prevents Hypertension, Proteinuria, and Poor Feto-Placental Outcomes in BPH/5 Mouse Model of Preeclampsia

et al. 2008

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“…In particular, many groups have obtained both high oxygen and spatial resolution images of oxygen in the tumors of mice from cw ESR imaging (ESRI) at radiofrequency . ESRI is widely used to study the free radical distribution in biological systems in the USA, Japan and other countries (Sotgiu et al, 1998;He et al, 2002He et al, , 2004Utsumi and Yamada, 2003;Herrmann et al, 2007). However, there is no in vivo ESR system in Korea.…”

Section: Application Of In Vivo Esr and Imagingmentioning

confidence: 98%

In vivo electron spin resonance: An effective new tool for reactive oxygen species/reactive nitrogen species measurement

Han

Hong

2010

Arch. Pharm. Res.

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Reactive oxygen species are regarded as important factors in the initiation and progression of many diseases. Therefore, measurement of redox status would be helpful in understanding the "Redox Navigation" of such diseases. Because electron spin resonance (ESR) shows good signal responses to nitroxyl radical and various redox-related species, such as oxygen radicals and antioxidants, the in vivo ESR/nitroxyl probe technique can provide useful information on real-time redox status in a living body. ESR spectrometers for in vivo measurements can be operated at lower frequencies (approximately 3.5 GHz, 1 GHz, 700 MHz, and 300 MHz) than usual (9-10 GHz). Several types of resonators were also 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 diseases. In addition, ESR has been used to analyze injury models related to oxidative stresses, such as nitroxyl radicals. The application of in vivo ESR for diseases related to oxidative injuries currently being investigated and the accumulation of basic data for therapy is ongoing. Recent progress in the instrumentation for in vivo ESR spectroscopy and its application to the life sciences are reviewed, because measurement of redox status in vivo is considered necessary to understand the initiation and progression of diseases.

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“…The frequently determined “mean value” of ĝ mainly inform about the nature of the participating heavy atoms in the paramagnetic centre. For free electrons a value of g e = 2.0023 was determined, while nitroxyl spin probes have value around 2.05 [6,7,37], and for heavy ion like Cu 2+ it will be around 2.2 [38].…”

Section: Electron Spin Resonance (Esr) and Relations To Isotope Efmentioning

confidence: 99%

“…For that purpose 15 N-TEMPO was dissolved in Precirol ® , while 14 N-TEMPOL was dissolved in Miglyol ® and brought into contact within a capillary tube. The spectral-spatial images and the respective spectra in different depths show the progress of the distribution after 5 and 240 min [37], respectively, are displayed in Figure 14.…”

Section: Selected Examplesmentioning

confidence: 99%

Isotope Effects in ESR Spectroscopy

Stößer

Herrmann

2013

Molecules

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In order to present the relationship between ESR spectroscopy and isotope effects three levels are considered: (i) ESR spectroscopy is described on a general level up to the models for interpretation of the experimental spectra, which go beyond the usually used time and mass independent spin-Hamilton operator, (ii) the main characteristics of the generalized isotope effects are worked out, and finally (iii) the basic, mainly quantum mechanical effects are used to describe the coupling of electron spins with the degrees of freedom, which are accessible under the selected conditions, of the respective paramagnetic object under investigation. The ESR parameters and the respective models are formalized so far, that they include the time and mass depending influences and reflect the specific isotope effects. Relations will be established between the effects in ESR spectra to spin relaxation, to spin exchange, to the magnetic isotope effect, to the Jahn-Teller effects, as well as to the influence of zero-point vibrations. Examples will be presented which demonstrate the influence of isotopes as well as the kind of accessible information. It will be differentiated with respect to isotope effects in paramagnetic centres itself and in the respective matrices up to the technique of ESR imaging. It is shown that the use of isotope effects is indispensable in ESR spectroscopy.

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ESR imaging investigations of two‐phase systems

Cited by 14 publications

References 28 publications

Chronic Tempol Prevents Hypertension, Proteinuria, and Poor Feto-Placental Outcomes in BPH/5 Mouse Model of Preeclampsia

Chronic Tempol Prevents Hypertension, Proteinuria, and Poor Feto-Placental Outcomes in BPH/5 Mouse Model of Preeclampsia

In vivo electron spin resonance: An effective new tool for reactive oxygen species/reactive nitrogen species measurement

Isotope Effects in ESR Spectroscopy

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