Minocycline Inhibits Mitochondrial Cytochrome C Release, Reduces Cell Death And Improves Functional Recovery After Spinal Cord Injury In Ratset

Objectives: To investigate the effect of minocycline on expression of mitochondrial Cytochrome C, apoptosis and functional recovery after spinal cord injury (SCI) in ratset.Methods:Fifty six adult SD rats with received a mild, weight-drop contusion injury to the spinal cord were divided randomly into two groups and were treated with the vehicle(groupB) or minocycline(groupA) at a dose of 90 mg/kg immediately after SCI and then twice at a dose of 45 mg/kg every 12h.The rats were sacrificed at 4h,8 h, ld,3d,7d,14d after surgery, and then the tissue sections of injured spinal cord were stained and evaluated with hematoxylin and eosin (HE),immunohistoehemistry and the flow cytometry (AnnexinV/PI).Injecting minocycline after SCI improved hind limb motor function was determined by the Basso-Beattie-Bresnahan (BBB) locomotor open field behavioral rating test, 3 days to 28 days after SCI.Results:The histopathological changes in injured spinal cord tissue observed with HE staining microscopic examination in group B was worse than that in group A. Expression of cytochrome c and apoptotic cells were observed both in two groups, and the apoptotie index and expression of cytochrome c in group B was higher than that in group A (P<0.01). 3 days to 28 days after SCI, BBB scores were significantly higher in minocycline-treate rats as compared with those in vehicle-treated rats.Conclusions:These data suggest that, after SCI, minocycline treatment modulated expression of cytochrome c, attenuated cell death and improved functional recovery in the injured rat. This approach may provide a therapeutic intervention enabling us to reduce cell death and improve functional recovery after SCI.