Research Paper Volume 8, Issue 11 pp 2713—2733

Figure 1. SkQ1 is predominantly localized to (and accumulates in) neuronal mitochondria. Four-month-old OXYS rats were treated with SkQR1 (250 nmol/kg) for 7 or 14 days (n = 4) to assess localization and accumulation of SkQ1. (A) High intensity of fluorescence signals of fluorescence signals of rhodamine-labeled of SkQ1 (red fluorescence) in neurons of the hippocampus in SkQR1-treated OXYS rats and the absence of specific signals in untreated (control) OXYS rats. The SkQR1 signal increased depending on the duration of treatment with the antioxidant (7 days < 14 day). (B) An example of accumulation of SkQR1 (in red) in hippocampal neurons of an OXYS rat. (C and D) Immunolabeling with an anti-COX-IV antibody (mitochondrial loading control; in green) shows that SkQR1 (in red) is localized to neuronal mitochondria. The arrows show colocalization of SkQR1 and COX-IV. Cell nuclei are stained with DAPI (in blue). The scale bars are 20 µm (A and B) and 5 µm (C and D).