Dissertation > Excellent graduate degree dissertation topics show

Toxicity of the Brominated Flame Retardant Tri (2,3-Dibropropyl) Isocyanurate (TBC) in Zebrafish

Author: ZhangXu
Tutor: ZhangJie；LiangYong
School: Huazhong Agricultural University
Course: Soil
Keywords: Persistent Organic Pollutants 3 - ( 2,3 - dibromopropyl ) isocyanurate Zebrafish Vitellogenin Endocrine disrupting effects
CLC: X174
Type: Master's thesis
Year: 2011
Downloads: 70
Quote: 0
Read: Download Dissertation

Abstract

3 - (2,3 - dibromopropyl) iso cyanurate (TBC) is a new in our natural environment detected the hexabromodiphenyl heterocyclic brominated flame retardants. TBC semi-volatile and fat-soluble, but its toxic effects on aquatic organisms is still unclear. Adult zebrafish (Danio rerio) as a model animal to study the TBC single composite of the TBC with 17β-estradiol exposure case, TBC zebrafish adult fish toxicity and toxic mechanism to explore TBC ecological potential environmental hazards. Of 0.25,1 and 4 mg / L the TBC were exposed to 28 days of zebrafish, detection zebra fish mortality, biopsy, hormone levels, enzyme activity, gene expression, and other indicators. The results showed TBC zebra fish mortality, body length, and body weight had no significant effect, but TBC can cause zebrafish gills, liver, gonads, and intestinal lesions varying degrees, including edema and fatty degeneration of the liver cells, gill wire cell proliferation and intestinal goblet cell hyperplasia. Meanwhile, TBC exposed zebrafish free triiodo thyroxine, free thyroxine, testosterone and estradiol levels had no effect; exposed group of female liver superoxide dismutase activity was significantly increased, but no difference in the male liver; TBC no effect on the exposure of fish brain cholinesterase activity; unable to induce CYP1A gene expression in zebrafish liver, but TBC exposure significantly inhibited the expression of vitellogenin (VTG) gene in zebrafish liver. Conducted TBC and 17p-estradiol (E2) composite exposure experiments to study the the TBC potential toxic mechanism. Showed that TBC can significantly with suppression E2 caused the zebra fish fertilizer full degree index rose, and can improve the E2 exposure caused zebrafish sperm cells in proportion to reduce and gonadal development retardation; E2 can cause zebrafish liver tissue fat-like lesions, liver MDA content increase in the activity of SOD did not significantly change; TBC composite after exposure, the content of MDA presented a downward trend, but the fish liver still apparent fat-like lesions, liver SOD vitality also not significant with impact; more important is, TBC can be significant with Inhibition of vitellogenin gene expression in the E2 single exposure induced male liver. To TBC, reproductive toxicity, female zebrafish exposed TBC 14 days after spawning experimental study results show that: the TBC can cause zebra fish spawning capacity change affects the F1 zebrafish hatching rate, increased juvenile Maw malformation , lower the swim bladders area. But these effects gradually disappear with the prolonged recovery time. Implied transferred from the mother to the offspring is one of the major metabolite of TBC in female zebrafish. In addition, clean water is restored, the zebrafish brain SOD activity of the control group was significantly increased, TBC exposed zebrafish SOD activity in the brain without significant changes in the TBC reduces stress capacity of the fish brain, suggesting TBC might be cause irreversible brain tissue. The TBC may affect VTG in zebrafish liver gene expression due to inhibition of E2-induced obesity and E2-induced expression of VTG, combined TBC zebra fish into fish gonads, show that TBC potential endocrine disrupting effects, TBC such heterocyclic bromine of flame retardants on the aquatic environment need further attention.

Related Dissertations

CLC: > Environmental science, safety science > The basic theory for the Environment and Science > Environmental Biology > Environmental zoology
© 2012 www.DissertationTopic.Net Mobile