Measuring brain tissue oxygenation under oxidative stress by ESR/MR dual imaging system.
The in vivo measurement of oxygen in tissues is of great interest because of oxygen's fundamental role in life. Many methods have been developed for such measurement, but all have been limited, especially with regard to repeated measurement, degree of invasiveness, and sensitivity. We describe electron spin resonance (ESR) oximetry with paramagnetic oxygen-sensing probe for in vivo measurement of oxygen in brain tissues by home-made ESR/MR dual imaging spectroscopy. Lithium 5, 9, 14, 18, 23, 27, 32, 36-octa-n-butoxy-2,3-naphthlocyanine (LiNc-BuO) radical was employed as the solid oxygen-sensing probe, and we confirmed its ability to report partial pressure of oxygen (pO(2)) in brain tissues of live animals under normal and pathological conditions for more than a month. pO(2) measurements could also be made repeatedly on the same animal and at the same location. The implantation site of LiNc-BuO in examined rats was verified by 0.5 T magnetic resonance (MR) imaging. Septic-shock rats were used to monitor tissue oxygenation during pathological state. A decline in pO(2) levels from severe hypotension during sepsis was detected, and generation of nitric oxide (NO) in brain tissues was confirmed by NO spin trapping. ESR oximetry using oxygen-sensing probe and NO spin-trapping can be used to monitor pO(2) change and NO production simultaneously and repeatedly at the same site in examined animals.
Fujii
Hirotada
H
School of Health Sciences, Sapporo Medical University, Sapporo, Japan. hfujii@sapmed.ac.jp
Itoh
Kouichi
K
Pandian
Ramasamy P
RP
Sakata
Motomichi
M
Kuppusamy
Periannan
P
Hirata
Hiroshi
H
D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage; D004195:Disease Models, Animal; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D019786:Gadolinium DTPA; D007022:Hypotension / Q000209:etiology; D021621:Imaging, Three-Dimensional / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008665:Metalloporphyrins; D009569:Nitric Oxide / Q000096:biosynthesis; D018384:Oxidative Stress; D010100:Oxygen / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000378:metabolism*; D019097:Spin Trapping / Q000379:methods
D003287:Contrast Media; D008665:Metalloporphyrins; C481390:lithium 5,9,14,18,23,27,32,36-octa-n-butoxy-2,3-naphthocyanine; D009569:Nitric Oxide; D019786:Gadolinium DTPA; D010100:Oxygen