Adult C57b1 Mice Could Develop Symptoms Similar to Parkinson′s Disease after the Exposure to Paraquat

Aim:To observe the influence of paraquat on the nigro striatal system in the adult C57b1 mice chronically exposed to paraquat. Methods:48 adult C57b1 mice were randomly divided into 3 groups and exposed to MPTP 20 mg·kg -1 body weight ( n =16), paraquat 10 mg·kg -1 body weight ( n =16) or the same amount normal saline ( n =16) taken respectively by oral administration every day for 2 months. Spontaneous motor activities were observed during the process, at the end point of the study,these mice were decapitated and the contents of dopamine (DA),serotonin (5 HT), and metabolites in striatum were analyzed,meanwhile,the dopamine neurons at the mesencephalon were observed by the method of ABC immunohistochemistry. Results:In the paraquat (10 mg·kg -1 ) and MPTP(20 mg·kg -1 ) treated mice, a marked hypoactive behavior was observed, the striatal content of DA and metabolites were reduced without affecting 5 HT, and the number of dopaminergic neurons at the midbrain was decreased. Conclusion:C57b1 mice chronically exposed to the great amount of paraquat could yield the alterations of behavior and pathology and biochemistry similar to PD.