EPR imaging to estimate the in vivo intracerebral reducing ability of mature rats after neonatal hypoxic-ischemic brain injury.
A rat model of neonatal hypoxic-ischemic encephalopathy (Rice's model) was obtained by unilateral ligation of the common carotid artery of 7-day-old rats with hypoxia (exposure to 8% oxygen). To estimate the in vivo intracerebral reducing ability of the mature rats (8 weeks old) of Rice's model, temporal electron paramagnetic resonance (EPR) imaging of the brain of a rat receiving a blood-brain barrier-permeable nitroxide radical, 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl, was performed. In this imaging technique, the decay rate of the EPR signal intensity in a selected region of the brain is indicative of region-specific reducing ability. The effect of neonatal treatment of an antioxidant agent, 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186), after a hypoxic-ischemic insult was also tested. It was found that the reducing ability had been depleted in the contralateral hemisphere of Rice's model rats; this depletion was suppressed by administering MCI-186.
Yokoyama
Hidekatsu
H
Institute for Life Support Technology, Yamagata Promotional Organization for Industrial Technology, Yamagata 990-2473, Japan. yokohide@fmu.ac.jp
Ueda
Yuto
Y
Itoh
Osamu
O
Ikeda
Tomoaki
T
Noor
Jesmin I
JI
Ikenoue
Tuyomu
T
D000818:Animals; D000831:Animals, Newborn; D000983:Antipyrine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D001812:Blood-Brain Barrier / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D017536:Carotid Artery, Common / Q000503:physiopathology; D003497:Cyclic N-Oxides / Q000493:pharmacokinetics; D004195:Disease Models, Animal; D000077553:Edaravone; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D016166:Free Radical Scavengers / Q000627:therapeutic use; D020925:Hypoxia-Ischemia, Brain / Q000209:etiology / Q000378:metabolism*; D008026:Ligation / Q000379:methods; D018696:Neuroprotective Agents / Q000493:pharmacokinetics; D010084:Oxidation-Reduction; D011759:Pyrrolidines; D051381:Rats; D017208:Rats, Wistar
D003497:Cyclic N-Oxides; D016166:Free Radical Scavengers; D018696:Neuroprotective Agents; D011759:Pyrrolidines; C050260:3-hydroxymethyl-2,2,5,5-tetramethylpyrroline-N-oxyl; D000077553:Edaravone; D000983:Antipyrine