An analysis of the intracerebral ability to eliminate a nitroxide radical in the rat after administration of idebenone by an in vivo rapid scan electron spin resonance spectrometer.

Electron spin resonance (ESR) measurements after intracerebroventricular injection of a nitroxide radical were carried out in rats (n = 6) that received oral idebenone for 2 weeks and in control rats (n = 5), using an in vivo rapid scan ESR spectrometer. The half-life of nitroxide, which was estimated from the change in the peak height (delta M = +1) of the ESR signals from the head, was used as a marker for the elimination of the nitroxide radical. The half-life in the rats treated with idebenone was significantly shorter than it was in the controls (p < 0.05). This finding indicates that the treatment with idebenone can enhance the intracerebral-eliminating ability of the nitroxide radical.