ZFET (Zebrafish embryo toxicity test) as a model test for determination of heavy metals embryo toxicity

Анотація

ZFET (Zebrafish embryo toxicity test) is established by OECD as a mandatory step for testing the toxicity of water pollutants and manufacturing sewage waters. Test is based on 72 h exposure of Danio rerio embryos in vitro to testing chemical (heavy metals in current study) and subsequent analysis of embryos mortality and malformations. As the result of present investigation it was shown the dose-dependent embryolethal but not teratogenic effect of CdSO4. Concentration of 3,5х10-5М CdSO4 may be considered as minimal 100% lethal concentration for 3 h exposition. Maximum embryos death by 24 hpf was the result of deep life-incompatible malformations and subsequent embryos coagulation. Survived embryos showed no significant signs of abnormality and developed normally. At the same time Pb(CH3COO)2 in studied concentrations acted as disruptor of normal embryogenesis, however there was no embryo lethal effect observed. Approximately 80% of embryos exposed to 8,125х10-3М and 812,5х10-3М Pb(CH3COO)2 showed signs of scoliosis, accompanied by tail tip malformations covering an average 40% of exposed embryos. It is also possible that observed negative effects of lead are the result of increased chorion permeability and alteration of water and salt balance in embryo. Based on the results of experiments it was concluded that cadmium is considered to be highly toxic to zebrafish embryos, dose comparison testify the threefold degree cadmium toxicity to zebrafish embryos comparing with lead.