Effects of different concentrations of dimethylsulfoxide on development of zebrafish embryos and dopamine neurons

Abstract

bjective To study the effect of exposures to different concentrations of dimethyl sulfoxide (DMSO) on the development of zebrafish embryos and dopaminergic (DA) neurons. Methods Tg(Vmat2 :GFP) zebrafish embryos of the same generation were randomized into 10 groups at 6 h post-fertilization for exposures to 9 concentrations (0.1%, 0.3%, 0.5%, 0.8%, 1.0%, 1.5%, 2.0%, 2.5%, and 3.0%; V/V) of DMSO for 72 h or without any exposure (blank control group). The survival rate, deformity rate, hatching rate and behavioral changes of the embryos were analyzed. The development of DA neurons was observed using laser confocal microscopy, and the cell proliferation and apoptosis were detected using PH3 antibody and an apoptosis detection kit, respectively. Results Exposure to 2.5% DMSO significantly decreased the survival rate of the zebrafish embryos (P < 0.01); at the concentration of 2.0%, DMSO exposure caused an obvious increase in the malformation rate (P < 0.01) and a decrease in the hatching rate of the embryos (P < 0.05); DMSO at 2.5% significantly decreased the frequency of tail swing of the zebrafish embryos (P < 0.05). Zebrafish embryos exposed to 0.5% DMSO showed a significantly reduced number of DA neurons (P < 0.05). Exposure of the zebrafish embryos to DMSO at a concentration above 0.3% significantly reduced the proliferation of the diencephalon cells (P < 0.01), and a DMSO concentration above 0.8% could obviously increase apoptosis of the dopaminergic neurons. Conclusion DMSO exposure causes developmental disorders in zebrafish embryos, and its neurotoxicity can result in loss of dopaminergic neurons in the diencephalon and suppress the cell proliferation