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Improved Sensitivity for Imaging Spin Trapped Hydroxyl Radical at 250 MHz
Author(s) -
Biller Joshua R.,
Tseitlin Mark,
Mitchell Deborah G.,
Yu Zhelin,
Buchanan Laura A.,
Elajaili Hanan,
Rosen Gerald M.,
Kao Joseph P. Y.,
Eaton Sandra S.,
Eaton Gareth R.
Publication year - 2015
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201402835
Subject(s) - electron paramagnetic resonance , radical , chemistry , pulsed epr , adduct , spin trapping , spin (aerodynamics) , nuclear magnetic resonance , photochemistry , paramagnetism , analytical chemistry (journal) , magnetic resonance imaging , spin echo , physics , organic chemistry , thermodynamics , medicine , quantum mechanics , radiology
Radicals, including hydroxyl, superoxide, and nitric oxide, play key signaling roles in vivo. Reaction of these free radicals with a spin trap affords more stable paramagnetic nitroxides, but concentrations in vivo still are so low that detection by electron paramagnetic resonance (EPR) is challenging. Three innovative enabling technologies have been combined to substantially improve sensitivity for imaging spin‐trapped radicals at 250 MHz. 1) Spin‐trapped adducts of BMPO have lifetimes that are long enough to make imaging by EPR at 250 MHz feasible. 2) The signal‐to‐noise ratio of rapid‐scan EPR is substantially higher than for conventional continuous‐wave EPR. 3) An improved algorithm permits image reconstruction with a spectral dimension that encompasses the full 50 G spectrum of the BMPO–OH spin adduct without requiring the wide sweeps that would be needed for filtered backprojection. A 2D spectral–spatial image is shown for a phantom containing ca. 5 μ M BMPO–OH.