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Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR
Published on: February 23, 2016
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Free Radical Imaging Using In Vivo Dynamic Nuclear Polarization-MRI
Hideo Utsumi1, Fuminori Hyodo1
1Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka, Japan.
Methods in Enzymology
|October 20, 2015
Summary
Dynamic nuclear polarization magnetic resonance imaging (DNP-MRI) noninvasively measures free radicals in vivo. This technique reflects redox status and aids in studying oxidative stress and antioxidant drug efficacy.
Area of Science:
- Biomedical Imaging
- Free Radical Chemistry
- Oxidative Stress Research
Background:
- Redox reactions are vital for metabolism but can generate reactive oxygen species, contributing to oxidative stress-related diseases.
- In vivo electron spin resonance (ESR) imaging allows direct, noninvasive measurement of free radical reactions.
- Dynamic nuclear polarization magnetic resonance imaging (DNP-MRI) is an emerging technique for visualizing free radical species within living organisms.
Purpose of the Study:
- To introduce and evaluate dynamic nuclear polarization magnetic resonance imaging (DNP-MRI) as a tool for in vivo free radical detection.
- To demonstrate the capability of DNP-MRI in assessing redox status and oxidative stress.
- To explore the potential of DNP-MRI in evaluating the efficacy of antioxidants.
Main Methods:
- Development and application of an in vivo electron spin resonance (ESR) spectrometer and imaging system.
- Utilizing dynamic nuclear polarization magnetic resonance imaging (DNP-MRI), also known as PEDRI or OMRI.
- Employing stable nitroxyl radicals as spin probes to detect in vivo redox reactions.
- Analyzing signal decay of nitroxyl probes using DNP-MRI to assess redox status.
Main Results:
- DNP-MRI provides spatiotemporal resolution comparable to conventional MRI for free radical imaging.
- Different radical species can be distinguished spectroscopically by adjusting ESR irradiation parameters.
- Signal decay of nitroxyl probes, measured by DNP-MRI, correlates with the redox status under oxidative stress.
- Antioxidant administration was shown to suppress the signal decay of nitroxyl probes.
Conclusions:
- In vivo DNP-MRI is a powerful noninvasive tool for observing free radical species and redox reactions.
- This technique can visualize intrinsic intermediate free radicals from biological molecules.
- DNP-MRI holds significant promise for investigating oxidative injury mechanisms in disease models and assessing in vivo antioxidant effects.
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