In vivo electrochemical detection of 5-hydroxyindoles in the dorsal hippocampus of anesthetized rats treated with idebenone (CV-2619).

The effect of idebenone (CV-2619), 6-(10-hydroxydecyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone, on 5-hydroxyindoles in the dorsal hippocampus of rats was investigated by using in vivo differential pulse voltammetry. CV-2619 (100 mg/kg, i.p.) produced a large increase in oxidation current at 280 mV (peak 2) in the dorsal hippocampus. The increase was statistically significant at 20 and 30 min after the administration. 5-Hydroxytryptophan (150 mg/kg, i.p.) also caused a marked increase in peak 2, which was clearly inhibited by the treatment with pargyline (50 mg/kg, i.p.). Thus, the increase in peak 2 induced by CV-2619 seems to be associated with an increase in the 5-HT metabolite 5-hydroxyindoleacetic acid and also partly with an increase in 5-HT.