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Effects of cadmium chromium and mercury alone and in combination of lung tussue of Sprague-Dawley rats

Dissertation (MSc)--University of Pretoria, 2019.

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Other Authors: Oberholzer, Hester Magdalena [
Format: Thesis
Language:English
Published: University of Pretoria 2019
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access_status_str Open Access
author2 Oberholzer, Hester Magdalena [
author_browse Oberholzer, Hester Magdalena [
author_facet Oberholzer, Hester Magdalena [
collection Thesis
dc_rights_str_mv © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MSc)--University of Pretoria, 2019.
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:40:03.959Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2019
publishDateRange 2019
publishDateSort 2019
publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/72655 Effects of cadmium chromium and mercury alone and in combination of lung tussue of Sprague-Dawley rats Oberholzer, Hester Magdalena [ naidoosirasha@gmail.com Bester, Megan J. Naidoo, Sirasha Venketsamy Koopsamy UCTD Cadmium Chromium Mercury Toxicological effects Heavy metal toxicity Health sciences theses SDG-03 SDG-03: Good health and well-being Dissertation (MSc)--University of Pretoria, 2019. Heavy metals are widely used in numerous applications and enviromental exposure has increased. The prevalence of respiratory disease worldwide has also increased dramatically and research has linked heavy metal exposure via inhalation to diseases of the respiratory system, particularly pulmonary fibrosis. The lungs are often overlooked when the toxicity of heavy metals after oral exposure is being investigated. Enviromental exposure is not limited to a single metal but as part of mixtures of metals. In the South African milieu cadmium, chromium and mercury are common metal contaminants in water. Therefore, the aim of this study was to investigate the effects of exposure to 1000 times the World Health Organization’s limits of cadmium, chromium and mercury alone and in combination on the lung tissue of Sprague-Dawley rats. Sprague-Dawley rats (6 rats per group including controls) were daily orally gavaged with dosages equivalent to a 1000 times, the World Heatlh Organisation’s limits for cadmium, chromium and mecruy alone and in combinations (Cd, Cr , Hg, Cd + Cr, Cd + Hg, Cr + Hg and Cd + Cr + Hg) for 28 days. After exposure the controls and exposed rats were terminated and the tissue and cellular structure of the bronchioles and lungs were evaluated. Tissue structure was evaluated using specific stains. Transmission electron microscopy was used to evaluate the ultrastructural changes in type I and II alveolar cells as well as the distribution of collagen and elastic fibers. In the exposed groups, thickening of the intra-alveolar space, desquamation of epithelial cells of the bronchioles with increase in cellular debris was observed. Additionally, the presence of bronchus-assoicated lymphoid tissue was observed, with increased displacement and distribution of collagen type III to type I. Elastin fibres appeared more fragmented along the basement membrane of the exposed groups compared to the control. Ultrastructural analyses revealed the detachment of the nuclear membrane of alveolar type II cells, with a prominent increase in collagen and elastin bundles and the presence of mast cells near injured alveolar type II cells. Mercury alone and the combinations containing mercury, (Cr + Hg, Cd + Hg and Cd + Cr + Hg) were the most toxic. In conclusion, this study identified, that following oral exposure to metals such as cadmium, chromium and mercury, the lungs are a specific target of toxicity. Therefore, in addition to aerosol heavy metal exposure, oral exposure can also contribute to lung damage and the development of lung fibrosis. em2025 Anatomy MSc Unrestricted SDG-03: Good health and well-being 2019-12-13T08:07:20Z 2019-12-13T08:07:20Z 19/09/06 2019 Dissertation Naidoo, SVK 2019, Effects of cadmium chromium and mercury alone and in combination of lung tussue of Sprague-Dawley rats, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/72655> S2019 http://hdl.handle.net/2263/72655 en © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Cadmium
Chromium
Mercury
Toxicological effects
Heavy metal toxicity
Health sciences theses SDG-03
SDG-03: Good health and well-being
Effects of cadmium chromium and mercury alone and in combination of lung tussue of Sprague-Dawley rats
title Effects of cadmium chromium and mercury alone and in combination of lung tussue of Sprague-Dawley rats
title_full Effects of cadmium chromium and mercury alone and in combination of lung tussue of Sprague-Dawley rats
title_fullStr Effects of cadmium chromium and mercury alone and in combination of lung tussue of Sprague-Dawley rats
title_full_unstemmed Effects of cadmium chromium and mercury alone and in combination of lung tussue of Sprague-Dawley rats
title_short Effects of cadmium chromium and mercury alone and in combination of lung tussue of Sprague-Dawley rats
title_sort effects of cadmium chromium and mercury alone and in combination of lung tussue of sprague dawley rats
topic UCTD
Cadmium
Chromium
Mercury
Toxicological effects
Heavy metal toxicity
Health sciences theses SDG-03
SDG-03: Good health and well-being
url http://hdl.handle.net/2263/72655