| Spinal cord ischemia-reperfusion injuryis(SCII) is one of the difficulties ofneuroscience research. SCII usually occurs after spinal cord injury, spinal cord againreceive blood perfusion after a certain period of ischemia and appearant dysfunction.In some cases, even resulting the phenomenon of irreversible spinal cord delayedneuronal death. The main damage caused by spinal cord ischemia-reperfusion injuryis secondary injury after reperfusion, which determined the prognosis of spinal cordischemia-reperfusion injury. Therefore, protecting the spinal cord neurons to avoidspinal cord edema, is the key to the treatment of spinal cord ischemia and reperfusioninjury.Aquaporin4is widely distributed in the spinal cord. The bi-directionaltransferation of water molecules specificity mediated by AQP4, which play a key rolein the maintenance of intracellular and extracellular osmotic pressure. Thepathogenesis of spinal cord ischemia-reperfusion injury is unclear, but earlypathological changes lead to tissue edema is the most important one of themechanisms. Thus, aquaporin4become a specific target for the treatment of spinalcord ischemia-reperfusion injury.Ginseng is a valuable medicine, which has extensive pharmacological effects andis mild in nature. Ginsenoside is the active ingredient extracted from the leaves andstems of ginseng. The Ginsenoside have more than50kinds of monomer have beenpurificated. In recent years, scholars tried to apply ginsenosides in nervous systemdisease and achieved a certain effects. However, the protective mechanism ofginsenosides on the central nervous system is still lack of in-depth research.Ginsenoside Rb1is a diol group ginsenosides, with the role of inhibition of the central nervous system, decreasing the intracellular calcium, antioxidant, remove free radicals,and reduction of myocardial ischemia and reperfusion injury. Therefore, we selectedginsenoside Rb1as the experimental drug.In this study, a spinal cord ischemia-reperfusion injury model of rats wasestablished. Application of BBB scoring system, HE staining, Nissl staining, the Tunelapoptosis detection evaluated neurological function of rats. Immunofluorescence,Western blot and Real-time PCR were applied to analysis the levels of AQP4proteinand mRNA, respectively. Observed above-mentioned changes after application ofginsenoside Rb1treatment, and offering new ideas for the exploitation of treatmentSCII drug.1. Effects of Ginsenoside Rb1on spinal cord ischemia-reperfusion injuryof ratsObjectives:Determined treatment effects of ginsenoside Rb1on SCII and finding the appropriatetreatment doseMethods:One handred and twenty Sprague–Dawley rats were randomly divided into fivegroups with twelve rats in each group. The groups were: blank group; SCII group;ginsenoside Rb1-treated group with5mg/kg·d; ginsenoside Rb1-treated group with10mg/kg·d; and ginsenoside Rb1-treated group with20mg/kg·d. Abdominal aorticclipping method establishes the SCII model, and given intraperitoneal injection ofdifferent doses of ginsenoside Rb1intervention. BBB scoring system to evaluate thenerve function, organizational structure and cell morphology were determined by HEstaining. The apoptosis was detected by Tunel.Results:Hind limb dysfunction appearant in all the following groups including SCII group;ginsenoside Rb1-treated with5mg/kg·d group; ginsenoside Rb1-treated with10mg/kg·d group; and ginsenoside Rb1-treated with20mg/kg·d group. But the degree of dysfunction is different. After10mg/kg·d ginsenoside Rb1-treated for1day, theBBB score was significantly higher than those of SCII group (P<0.05) and5mg/kg·dginsenoside Rb1-treated group (P<0.05). Interestingly,20mg/kg·d ginsenoside Rb1-treated for1day also could increase the BBB score compared to SCII group (P<0.05)and5mg/kg·d ginsenoside Rb1-treated group (P<0.05). However, we failed to detectany difference for20mg/kg·d ginsenoside Rb1-treated as compared to that of10mg/kg·d ginsenoside Rb1-treated (P>0.05). Cell morphology study found, in SCIIgroup, some neurons damaged, some neuron body swelling, structure of neuron isunclear, cell nucleus condensation, inter-organizational congestive. Given differentdoses of ginsenoside intervention can improve the cell morphology. Givenginsenoside (either10mg/kg·d or20mg/kg·d) interve for7days, cell structuresignificantly improved and nuclear structure becomes clear. Tunel study showedapoptosis was significantly increased of SCII group compared to blank group at5dand7d (P<0.05). Apoptosis rate of different ginsenoside Rb1dose groups comparedto the blank group had no significant difference. Apoptosis rate of ginsenoside Rb1group was markedly lower than that of SCII group (P<0.05). At the same time, furtherstudies showed that apoptosis rate of Rb1-treated with10mg/kg·d group wassignificantly lower than that of Rb1-treated with5mg/kg·d group (P<0.05). However,the apoptosis rate have no significant difference between Rb1-treated with10mg/kg·dgroup and Rb1-treated with20mg/kg·d group (P>0.05).Conclusion:Ginsenoside Rb1has therapeutic effect on SCII, and the appropriate dose is10mg/kg·d. 2. Expression of AQP4on spinal cord ischemia-reperfusion injury of rats Objectives:To establish a rats model of spinal cord ischemia-reperfusion injury, to explore theeffect of AQP4on spinal cord ischemia-reperfusion injury, and its possiblemechanism.Methods:Sprague–Dawley rats were randomly divided into three groups with twenty-four ratsin each group. The groups were: sham operation; blank group; and spinal cordischemia-reperfusion injury at1,3,5, or7days after reperfusion started, six rats ofevery group were then killed, and the spinal cords were quickly removed, and theexpression of AQP4was determined by western-blot and immunofluorescence.Results:The scores of spinal cord injury was determined by BBB system. At different time,the BBB score of blank group and sham operation have no fluctuations, and has nosignificant differences. In spinal cord ischemia-reperfusion injury group, the BBBscore has a dynamic change, with a significant increasing at1d～7d, going to thehighest level at5d and7d, and the acore at5d and7d have no significant differences.The AQP4protein production were markedly lower than those of blank group at1d,3d,5d and7d, respectively. At the same time, the AQP4measured also byimmunofluorescence, the expression of AQP4in spinal cord ischemia-reperfusioninjury group significant decreased compared to another two groups from1d, thengradually increased, but until7d, the AQP4expression still lowed than those of shamoperation group and blank group (P<0.05).Conclusion:The AQP4level was significantly decreased in the SCII early phase, AQP4expressiongradually recovery with time tration, indicating that the low expression of AQP4might play an important role in the mechanisms of SCII neurological dysfunction. 3. Effects of ginsenoside Rb1on spinal cord ischemia-reperfusion injuryand its mechanism.Objectives:To investigate the effect of ginsenoside Rb1on spinal cord ischemia-reperfusioninjury of rats and its mechanism.Methods:Ninety-six Sprague–Dawley rats were randomly divided into four groups withtwenty-four rats in each group. The groups were: blank group; sham operation; SCIIgroup; and ginsenoside Rb1-treated group. In ginsenoside Rb1-treated group,intraperitoneal injection with ginsenoside Rb110mg/kg·d for7days. At1,3,5, or7days after reperfusion started, six rats of every group were then killed, and thefollowing studies were performed: the scores of spinal cord injury was determined byBBB system, the organizational structure were analyzed by HE staining, Nisslstaining, and the apoptosis rate was measured by Tunel. The AQP4expression wasdetected with immunofluorescence, Western blot and Real-time PCR.Results:The BBB score of ginsenoside Rb1-treated group was higher than that of SCII group.Ginsenoside Rb1had protect effects on the morphous of neurone, and compared withthe SCII group, the congestion of tissue space and cellular swelling were signifficantreduced. Nissl staining showed, the structure of Nissl body was obscure, presentinggranular, surface loosening in SCII group, and the impairment was significantlyinhibited by ginsenoside Rb1. Tunel also found ginsenoside Rb1treatment cansignificantly reduced apoptosis compared with SCII group. The dynamic changes ofAQP4in SCII was significantly decreased from1d to7d, especially in1d. Withginsenoside Rb1treatment, AQP4expression could notably been up-regulated. Theseresults indicate that ginsenoside Rb1could partly block the AQP4reduction causingby SCII.Conclusion:Ginsenoside Rb1had treatment effects on SCII. The possible mechanism may be involved with up-regulation AQP4expression, reduction nerve adema and apoptosis. |
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