Immunohistochemical Study On Expression Of BDNF In Paraquat Poisoning Rats’ Brain And The Therapeutic Effects Of Cyclosporine-A

Objective:To study the expression of BDNF and NOS in chronic paraquat poisoning rats’ brain through setting up the model by small doses of paraquat intraperitoneal injection to C57 BL rats,and the therapeutic effects of cyclosporine-A to paraquat.Methods:Thirty-five seven-week C57 BL rats were randomly divided into three groups:7 rats for control group,14 rats for experimental group,and the last 14 rats for cyclosporine-A treatment group.The control group,experimental group and the treatment group were respectively given 0.9% normal saline 10mg/Kg,20% paraquat 10mg/Kg,20% paraquat 10mg/Kg by intraperitoneal injection, for twice a week,and last to six weeks.Then the treatment group were given cyclosporine-A for therapy.In the process of setting up the models,gave continuous observation on rats’ behavioral changes in three groups,including suspending experiment and automatic activities counting. All rats were decapitated and the brain tissue were collected and fixed for paraffin embedding、section and immumohistochemical study.Results:1..C57 BL rats with small doses paraquat intraperitoneal injection in a long term have poor nutrition status and decrease significantly in automatic activities,suspension time and the respond to the outside.2.The expression of BDNF and iNOS are significantly enhanced in experimental group,mainly distribute in striatum and substantial nigra.3.The behavioral changes of treatment group are not significantly different with the experimental group.4.The expression of iNOS are less than experimental group in the same parts.However,the result indicate that the expression of BDNF has been enhanced.Conclusion:1.The expression of BDNF and iNOS will be enhanced in paraquat poisoning rats’ brain and be found mainly in substantial nigra.The mechanism of paraquat poisoning to brain may be relation to neuron apoptosis and lipid peroxidation.2..Treated with cyclosporine-A, iNOS immunohistochemical expression decreased in the brain while the behavioral changes cannot be improved.Cyclosporine-A has a good effect on inhibition of lipid peroxidation.3..Chronic exposure to paraquat will affect the nutrition status of rats, produce the same symptoms with Parkinson’s disease.