A novel lipophilic spin probe for the measurement of radiation damage in mouse brain using in vivo electron spin resonance (ESR)
As a possible lipophilic spin probe of in vivo electron spin resonance (ESR), 3-methoxy carbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-yloxy (MCPROXYL) was examined. The permeability of the blood-brain barrier to this compound was evaluated with a brain uptake index and autoradiography, with result that this probe is well distributed in the brain. The in vivo ESR spectra were measured in the head and the abdomen of MCPROXYL-injected living mice. The rate of signal decay of MCPROXYL in the head measured at one hour after X-irradiation was about 75% of that of the controls. The decrease in the head seems to be related to the early response of the brain to X-irradiation. This is the first report that the behavior of free radical such as MCPROXYL in the brain is influenced by X-irradiation. MCPROXYL is thus useful as a novel spin probe for in vivo ESR to monitor the radiation damage in the brain.
Miura
Y
Y
Department of Bioregulation Research, National Institute of Radiological Sciences, Chiba-shi, Japan.
Anzai
K
K
Takahashi
S
S
Ozawa
T
T
D000818:Animals; D001812:Blood-Brain Barrier / Q000502:physiology*; D001921:Brain / Q000378:metabolism* / Q000528:radiation effects; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005260:Female; D008297:Male; D051379:Mice; D011759:Pyrrolidines / Q000138:chemical synthesis / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D013113:Spin Labels / Q000138:chemical synthesis
D003497:Cyclic N-Oxides; C109806:MCPROXYL; D011759:Pyrrolidines; D013113:Spin Labels