Influence of Paraquat on the System of Substantial Nigra and Striatum in C57BL Mice

Purpose To investigate the influence of paraquat on substantial nigra and dopamine levels of striatum in C57BL mice. Methods 39 neonatal C57BL mice were randomly divided into 5 groups and were given paraquat or 1 methyl 4 phenyl 1,2,3,6 tetra hydropyridine(MPTP) orally in 10 th and 11 th days odl;(1) MPTP 0.3 mg/kg, n=8 ;(2) MPTP 20 mg/kg, n=8 ;(3) paraquat 0.07 mg/kg, n=8 ;(4) paraquat 0.36 mg/kg, n=8 ;(5) normal saline, n=7 .Adult spontaneous motor activity was observed at ages of 120 days,then the mice were decapitated and the contents of dopamine(DA),serotonin(5?HT),and their metabolites in striatum were analyzed.Meanwhile,the dopamine neuons at the mesencephalon were observed by the method of ABC immunohistochemistry. Results Mice given Paraquat 0.36 mg/kg and MPTP 20 mg/kg showed a marked bypoactive behavior and reduced the striatal contents of DA and metabolites without affecting 5?HT.Immunohistochemical staining showed that the amount of dopamine neurons at the midbrain decreased. Conclusions C57BL mice exposed to great amount of paraquat during the neonatal period could yield the alterations of behavior and some pathological and biochemical changes similar to parkinson disease.