TEMPORAL BRAIN IMAGING BY A RAPID SCAN ESR-CT SYSTEM IN RATS RECEIVING INTRAPERITONEAL INJECTION OF A METHYL-ESTER NITROXIDE RADICAL

We performed in vivo ESR-CT (electron spin resonance-computed tomograp hy) on rats' heads, in which the blood-brain barrier-permeable nitroxi de radical, hoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCAM) was injected intraperitoneally, using a rapid scan ESR-CT system opera ting at 700 MHz. In a spatiotemporal study we found that different reg ions of the brain showed differences in the rate of decay of the radic al, Repeated injection of PCAM gave clear ESR-CT images of the brain. We think that the present method is useful for evaluating the capacity to eliminate exogenous free radicals in some parts of the brain. (C) 1997 Elsevier Science Inc.