Mechanisms of immunotoxic effects of nanomaterial in fish

• Main Author: Costa, Leonor Coutinho
• Other Authors: Ahmad, Iqbal, Pereira, Maria Eduarda da Cunha
• Format: Master Thesis
• Language: English
• Published: Universidade de Aveiro 2013
• Subjects: Química analítica; Toxicologia ambiental - Ecossistemas aquáticos; Nanomateriais; Mercúrio - Toxicidade; Immunotoxicity; Reactive oxygen species; Antioxidants; Anguilla anguilla L; Nanomaterials; Mercury; Anguilla anguilla; European eel
• Online Access: http://hdl.handle.net/10773/12616

Mestrado em Química - Química Analítica e Qualidade Information and knowledge related to nanotechnology raise new challenges to the scientific community mainly in terms of human health risks and environmental implications associated to nanomaterials. In this perspective, the contamination of aquatic environments cannot be overlooked since it is an ultimate repository of the contaminants where this emerging appears as part of a cocktail of different classes of contaminants. Thus, the major task of this work was to connect gaps in current knowledge with a comprehensive sequence of biological responses toward environmentally relevant concentrations of engineered nanomaterials (IONM - silica coated iron oxide nanomaterial functionalized with dithiocarbamate group) and their interaction with other conventional anthropogenic contaminant (Hg - mercury), outlining the interaction with the innate immune system of fish. The research was divided into following steps: i) phagocytes macrophages were isolated from peritoneum (P-phagocytes), gill (G-phagocytes), head kidney (HK-phagocytes) and spleen (S-phagocytes) of European eel Anguilla anguilla L. in order to evaluate whether, and how can IONM and its co-exposure to Hg modulate phagocytes status and function; ii) determine the changes in phagocytes activation and their association to peroxidative damage (OBA - oxidative burst activity; LPO - lipid peroxidation); iii) to assess the impact of IONM on phagocytes enzymatic (CAT - catalase; GPX - glutathione peroxidase; GR - glutathione reductase; and GST - glutathione S-transferase) and non-enzymatic (NP-SH - non-protein thiols; and TGSH - total glutathione) antioxidants protection overtime. It was hypothesized that IONM can cause measurable changes in fish immune response and oxidative stress modulation. A period of exposure-dependency was exhibited by IONM alone and IONM+Hg joint exposures accrued impacts on A. anguilla phagocytes. IONM exposure alone lead to an acute response in terms of viability increase in P-phagocytes ...