Premium
In vivo oximetry using a nitroxide‐liposome system
Author(s) -
Glockner James F.,
Chan HsiaoChang,
Swartz Harold M.
Publication year - 1991
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910200113
Subject(s) - nitroxide mediated radical polymerization , liposome , chemistry , electron paramagnetic resonance , spin probe , oxygen , in vivo , aqueous solution , limiting oxygen concentration , nuclear magnetic resonance , analytical chemistry (journal) , chromatography , biochemistry , polymerization , radical polymerization , physics , microbiology and biotechnology , organic chemistry , biology , polymer
Liposomes containing the deuterated, charged, aqueous soluble nitroxide 4‐trimethylammonium‐2,2,6,6‐tetramethylpiperidine‐d 16 ‐1‐oxyl (d‐Cat 1 ) were used as probes to measure oxygen concentrations in vivo . Following intramuscular or intraperitoneal injection of the liposome suspension, ICR mice were placed over the surface probe of a low frequency (1.1 GHz) electron paramagnetic resonance (EPR) spectrometer. The linewidth of the deuterated nitroxide is sensitive to changes in the dissolved oxygen concentration: this parameter was calibrated separately so that linewidths measured in the injected mice could be converted into oxygen tensions. This technique detected substantial changes in pO 2 as the oxygen content of the breathing gas was changed from 21 to 85 to 0%. Intravenous injection of the liposomes also is possible, and the liposomes accumulate in the liver and spleen, where detectable, oxygen‐sensitive EPR signals can be measured. © 1991 Academic Press, Inc.