[Brain distribution of idebenone (CV-2619) and its effect on local cerebral glucose utilization in rats]

To investigate the possible action-sites of a cerebral metabolism activator, idebenone (CV-2619), its distribution in the brain and effect on local cerebral glucose utilization (LCGU) were studied both in normal rats (WKY) and in stroke-prone spontaneously hypertensive rats (SHRSP) with cerebrovascular lesions. At 5 min after intravenous administration of [14C] CV-2619 (10 mg/kg), the distribution ratio in the brain was 0.45-0.56% of the dosage. Autoradiographic study showed that 14C levels were higher in the white matter than in the grey matter. When [14C] CV-2619 was administered orally (100 mg/kg) and intraperitoneally (30 mg/kg), 14C levels in eleven brain regions (15 min after administration) were 0.22-0.39 microgram/g (CV-2619 equivalent) and 1.11-1.30 micrograms/g, respectively, in WKY and 0.17-0.28 microgram/g and 1.66-1.87 microgram/g, respectively, in SHRSP. Total 14C levels were not markedly different among the brain regions of the rats. The analysis of unchanged CV-2619 and its metabolites revealed that unchanged CV-2619 in the cerebral cortex, thalamus and cerebellum was relatively higher than that in the other brain regions. Studies on LCGU demonstrated that CV-2619 (30 mg/kg/day, i.p., for 3 days) improved the decrement of LCGU in the temporal cortex, thalamus dorsomedial nucleus, subthalamic nucleus, mamillary body, hippocampus dentate gyrus, caudate-putamen, inferior colliculus and cerebellar nucleus of SHRSP with stroke. Based on these results, the possible action-sites of CV-2619 for its main pharmacological effects were discussed.