Electron Irradiation Of The Contusion Site Improves Locomotor Recovery In Spinal Cord Injured Rats

Part I Electron irradiation of the contusion site improves locomotor recovery in spinal cord injured ratsObjective To explore the effect of electron irradiation on the locomotor recovery of spinal cord injured rats.Methods 36 SD female rats were divided randomly into sham-operation group, spinal cord injury group and electron irradiation group. SCI model was made according to modified Allen's method. Rats were given electron irradiation 1d after SCI. Rats were given BBB scale score 1d, 1w, 2w.3w, 4w after spinal cord injury. Expression level of GAP-43 protein was semi-quantified by western blot analysis.Results: BBB score of SCI group 4w after injury was 8.6±0.57, while in electron irradiation group it was 11.5±0.9. Western blot results show that electron irradiation group had increased expression of growth-associated proteins-43 (GAP-43). Part II: Effect of Electron Irradiation on Microglia and Expression of Pro-inflammatory cytokine in the Acute Phase of Spinal Cord InjuryObjective: To investigate the effect of electron irradiation on microglia and expression of pro-inflammatory cytokine in the acute phase of spinal cord injury.Methods: 36 SD female rats were divided randomly into sham-operation group, spinal cord injury group and electron irradiation group. SCI model was made according to modified Allen's method. Rats were given electron irradiation 1d after SCI. Microglia was tested by immunohistochemistry method 3d after spinal cord injury. Expression of pro-inflammatory cytokine and proliferation cell nuclear antigen(PCNA) was measured by Western blot.Results: Immunohistochemistry results show that in sham-operation group microglia cells were resident and have small cell body ,while 3 day after spinal cord injury microglia were activated and become amenoid-shaped and the number of microglia was increased greatly. In electron irradiation group a significant reduction of activated microglia was observed. Western blot results show that the expression level of IL-1βand PCNA was remarkably attenuated in electron irradiation group.Conclusion: Electron irradiation could attenuate microglia proliferation and ameoliate expression of pro-inflammatory cytokine. Objective: To explore the effect of electron irradiation on glia scar formation after rat spinal cord injury.Methods: 24 SD female rats were divided randomly into sham-operation group, spinal cord injury group and electron irradiation group. SCI model was made according to modified Allen's method. Rats were given electron irradiation 1d after SCI. Expression of GFAP and NG2 were tested by immunohistochemistry and expression of GFAP were also measured by western blot.Results: In the sham-operation group, immunohistochemistry revealed scarce GFAP and NG2 expression; while in the SCI group, astrocytes became hypertrophic, proliferative, and form a dense network of astroglial processes as well as the production of NG2 surrounding the cavity site of lesion 4w post injury. Meanwhile, electron irradiation remarkably reduced astroglial proliferation and accumulation of NG2. Also decreased expression level of GFAP,Conclusion: Electron irradiation could inhibit formation of glia scar after rat spinal cord injury.