Objective      To study the effect of high concentration of glucose on the early development of embryos and dopaminergic neurons in zebrafish.       Methods      Vmat-GFP transgenic zebrafish was used. After fertilization

the embryos were divided into control

mannitol group (25 mmol/L) and glucose group (25 mmol/L). In 3 d after fertilization

the morphology of embryonic dopaminergic neurons was visualized under laser scanning confocal microscope (LSCM). The expression of PD (Parkinson’s disease)-related genes was measured using fluorescent quantitative polymerase chain reaction (PCR).       Results      Compared with control and mannitol group

the embryonic development in glucose group was retarded with cardiac abnormalities. Enhanced fluorescent intensity of Vmat-GFP and increased number of dopaminergic neurons in the telencephalon were also observed. In glucose group the expression of PD-related genes was upregulated

and particularly

upregulation of PARKIN was significant (P0.05).       Conclusion      High concentration of glucose (25 mmol/L) is toxic to embryonic development

but neurotrophic for dopaminergic neurons at the early stage of embryos in zebrafish.