Influence of Paraquat on the System of Substantial Nigra and Striatum in C57BL Mice / 复旦学报（医学版）

ABSTRACT

Purpose To investigate the influence of paraquat on substantial nigra and doparine levels ofstriatum in C57BL mice. Methods 39 neonatal C57BL mice were randomly divided into 5 groups andwere given paraquat or 1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine(MPTP) orally in 10 th and 11 thdays 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 atages of 120 days, then the mice were decapitated and the contents of dopamine(DA), serotonin(5-HT), andtheir metabolites in striatum were analyzed. Meanwhile, the dopamine neuons at the mesencephalon vereobserved by the method of ABC immunohistochemistry. Results Mice given Paraquat 0.36 mg/kg andMPTP 20 rng/kg showed a marked bypoactive behavior and reduced the striatal contents of DA andmetabolites without affecting 5-HT. Immunohistochemical staining showed that the amount of dopamineneurons at the midbrain decreased. Conclusions C57BL mice exposed to great amount of paraquat duringthe neonatal period could yield the alterations of behavior and some pathological and biochemical changessimilar to parkinson disease.