The Influence Of Spinal Cord Injury On Rat`s Astrocytes And The Intervention Of Madecassoside On Astrocytes

Objective:(1) To observe the influence of spinal cord injury on rat`s asrocytes.(2) To observe the intervention of Madecassoside on rat`s asrocytes after SCI, and to prove that it could improve the physical function of spinal cord by inhibiting the proliferation of astrocytes.Methods:(1) SD rat model by modified Allen`s assay for SCI were adopt. 60 rats were divided randomly into two groups: sham-operative group and model group. At 24h,72h,7d,14d,28d after operation, the changes of Astrocyte`s morphology, number and secretion, motor function of the rat hind limb and the pathological state of spinal were be observed; the content of MDA, NSE, GDNF, iNOS and the activity of SOD were detected.(2) SD rat model by modified Allen`s assay for SCI were adopt. 150 rats were divided randomly into five groups: sham-operative group, model group, and the groups treated with madecassoside(60mg/kg and 20mg/kg)and methylprednisolon(30mg/kg). At 24h,72h,7d,14d,28d after operation, the changes of Astrocyte`s morphology, number , secretion, motor function of the rat hind limb and the pathological state of spinal were be observed; the content of MDA, NSE, GDNF, iNOS and the activity of SOD were detected.Results:(1) Compared with the sham-operative group, at each time point, the astrocytes showed reactive hyperplasia, bigger volume and thicker cell processes; motor function of the rat hind limbs about the spinal cord injury model group were decreased; HE staining of spinal cord showed hemorrhage, edema, nuclear condensation, neuronal apoptosis, lightly stained Nissl bodies; and the level of MDA, GDNF and iNOS were increased, the level of NSE and the activity of SOD were decreased in spinal cord tissue.(2) Treatments with MC(60 and 20mg/kg) could significantily inhibit the proliferation of astrocytes ,ameliorate the motor function of the rat hind limbs and pathological outcomes, markedly decrease the elevation of MDA and iNOS and increase the content of NSE,GDNF and the activity of SOD; and treatments with MC( 60 mg/kg ) was more effective. Conclusion: The astrocytes of rats proliferate obviously after spinal cord injury. Treatments with MC(60 and 20mg/kg) could significantily improve the physical function of spinal cord by inhibiting the proliferation of astrocytes, and the effect of MC was in dose-dependent manner.