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Studies on toxicological effects of lead in animals for evaluation of worldwide environmental lead pollution
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| Title: | Studies on toxicological effects of lead in animals for evaluation of worldwide environmental lead pollution |
| Other Titles: | 環境中の鉛汚染評価のための生物における鉛の毒性影響に関する研究 |
| Authors: | Kataba, Andrew Browse this author |
| Keywords: | fish | | lead | | heart rate | | gene expression | | apoptosis | | spasm |
| Issue Date: | 25-Mar-2021 |
| Publisher: | Hokkaido University |
| Abstract: | Ubiquitous environmental lead (Pb) contamination is related to human activities with mining as one of the major contributors. A long history of lead-zinc mining in Kabwe, Zambia extensively polluted the environment and some isolated water bodies with lead. To this end, I explored the negative effects of the current Kabwe lead water levels on aquatic life using 2.5 hours post fertilization (hpf) old embryos zebrafish (Danio rerio) exposed to a wide range of Pb concentrations (1-5000 μg/L Pb) until 96 hpf. Exposure negatively impacted the development and survival of zebrafish embryos by inducing embryo coagulation mortalities, reduced hatching rates, lack of embryo hatching in a concentration dependant manner. At 24 hpf, elevated embryo burst activity at lowest level of exposure (1 μg/L Pb) and decreased burst count per minute beginning at 500 μg/L were recorded. At 100 – 500 μg/L Pb, exposure induced cardiovascular toxicity by reducing heart rate and increasing blood flow activity concurrently. At 72 hpf involuntary muscular twitching that increased in number and duration were recorded at 50-500 μg/L Pb. The Pb toxicity dysregulation of the oxidative stress system evidenced by downregulation of catalase, and upregulation of heme oxyeganse-1, glutathione-S-transferase, cytochrome c oxidase subunit I mRNA gene expressions. The proapoptotic gene, tumour protein 53 expression level were downregulated across exposed groups. In contrast, the antiapoptotic gene, B-cell lymphoma 2 were upregulated at the lowest exposure spectrum (1-25 μg/L) and downregulated from 50-500 μg/L Pb. The findings suggest that the developmental Pb exposure in zebrafish may be accompanied with deleterious effects within environmentally and regulatory Pb levels. |
| Conffering University: | 北海道大学 |
| Degree Report Number: | 甲第14541号 |
| Degree Level: | 博士 |
| Degree Discipline: | 獣医学 |
| Examination Committee Members: | (主査) 教授 坪田 敏男, 教授 石塚 真由美, 教授 齋藤 健（保健科学研究院）, 助教 中山 翔太 |
| Degree Affiliation: | 獣医学院（獣医学専攻） |
| Type: | theses (doctoral) |
| URI: | http://hdl.handle.net/2115/81709 |
| Appears in Collections: | 課程博士 (Doctorate by way of Advanced Course) > 獣医学院(Graduate School of Veterinary Medicine)
学位論文 (Theses) > 博士 （獣医学）
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