• Toxicological Research
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• v.9 no.2
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• pp.217-224
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• 1993

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a well-known dopamine neuron-specific toxin. But the involvement of oxidative damage in the pathogenesis of MPTP-induced parkinsonism is still uncertain. In this study, by using 2',7',-dichlorofluorescin diacetate(DCFH-DA) that detects intracellular oxidative processes, the effect of MPTP on dichlorofluorescein fluorescence in dissociated cells from fetal rat mesencephalon in culture was investigated. At 7th day in culture, cells were loaded with DCFH-DA, and exposed to 1 mM MPTP or MPP+. MPTP induced dichlorofluorescein-fluorescence which was peaked at 3 min and mostly faded away 30 min after MPTP treatment.

• Animal cells and systems
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• v.1 no.3
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• pp.497-505
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• 1997

Dopamine plays diverse roles in the fetal brain development and differentiation. However, the development of the dopaminergic neurons and its receptors has not been fully understood. In our studies, in situ hybridization and immunohistochemical methods were used to investigate the ontogeny of dopaminergic neurons and its receptor subtypes during the fetal development of the rat. In situ hybridization data showed that dopamine $D_1$ and $D_2$ receptor mRNAs were expressed in the ventricular and subventricular zones of ganglionic eminence, thalamus, hypothalamus, and cortical neuroepithelium on gestational day 13. Expression of dopamine $D_1$ and $D_2$ receptors during gestational days 17 and 19 reached the same or similar level of that in the adult brain. Expression of $D_1$ receptor mRNA preceded that of $D_2$ receptor mRNA in the early developmental stage, although this pattern was reversed with the sharp increase of $D_2$ receptor mRNA soon after. $D_2$ receptor mRNA was expressed in substantia nigra of mesencephalon of the fetal rat brain. However, $D_1$ receptor mRNA was not detected in substantia nigra. Our results indicate that dopamine might function in the fetal brain during the early gestational period.