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Öğe A comparative toxicity study between small and large size zinc oxide nanoparticles in tilapia (Oreochromis niloticus): Organ pathologies, osmoregulatory responses and immunological parameters(Pergamon-Elsevier Science Ltd, 2016) Kaya, Hasan; Aydin, Fatih; Gurkan, Mert; Yılmaz, Sevdan; Ates, Mehmet; Demir, Veysel; Arslan, ZikriTilapia (Oreochromis niloticus) was exposed to different sizes of zinc oxide nanoparticles (ZnO-NPs) to evaluate their organ pathologies (kidney, liver, gill, and intestine), osmoregulatory responses and immunological parameters. Sub-chronic exposure was conducted in fresh water with 1 and 10 mg/L concentrations of the small (10-30 nm) and large-size ZnO (100 nm) particles for 7 and 14 days. In this study, it is found that small and large forms of ZnO-NPs cause various pathologic findings in the target organs at all concentrations. These findings are increased of melanomacrophage aggregates, tubular deformations, necrosis and cytoplasmic vacuolations in the kidney, oedema, mononuclear cell infiltrations, fatty changes, pyknotic nuclei and hepatocellular vacuolations in the liver, hyperplasia, aneurysms, and epithelial liftings in the gills, and hyperplasia, swelled of goblet cells, villus deformations in the intestine. Results showed that respiratory burst and potential killing activity at the small-size ZnO concentration significantly increased compared to the control group (p < 0.05) but significant reductions of these parameters at the large-size ZnO concentrations compared to control (p < 0.05) were measured. These findings demonstrate the potential of each particle size to cause significant damage to the immune system. Moreover, because ZnO NPs inhibit the Na, K-F-ATPase activity at all concentrations and increase serum Ca2+ and Cl- levels especially in gill, these particles are osmoregulatory and toxicant for tilapia fish. As a summary, both sizes of the particles have led to organ damage, osmoregulatory changes and immune disorder in tilapia fish. (C) 2015 Elsevier Ltd. All rights reserved.Öğe Chronic exposure of tilapia (Oreochromis niloticus) to iron oxide nanoparticles: Effects of particle morphology on accumulation, elimination, hematology and immune responses(Elsevier Science Bv, 2016) Ates, Mehmet; Demir, Veysel; Arslan, Zikri; Kaya, Hasan; Yılmaz, Sevdan; Camas, MustafaEffects of chronic exposure to alpha and gamma iron oxide nanoparticles (alpha-Fe2O3 and gamma-Fe2O3 NPs) were investigated through exposure of tilapia (Oreochromis niloticus) to 0.1, 0.5 and 1.0 mg/L (9.2 x 10(-4), 4.6 x 10(-3) and 9.2 x 10(-3) mM) aqueous suspensions for 60 days. Fish were then transferred to NP-free freshwater and allowed to eliminate ingested NPs for 30 days. The organs, including gills, liver, kidney, intestine, brain, spleen, and muscle tissue of the fish were analyzed to determine the accumulation, physiological distribution and elimination of the Fe2O3 NPs. Largest accumulation occurred in spleen followed by intestine, kidney, liver, gills, brain and muscle tissue. Fish exposed to gamma-Fe2O3 NPs possessed significantly higher Fe in all organs. Accumulation in spleen was fast and independent of NP concentration reaching to maximum levels by the end of the first sampling period (30th day). Dissolved Fe levels in water were very negligible ranging at 4-6 mu g/L for alpha-Fe2O3 and 17-21 mu g/L for gamma-Fe2O3 NPs (for 1 mg/L suspensions). Despite that, Fe levels in gills and brain reflect more dissolved Fe accumulation from metastable gamma-Fe2O3 polymorph. Ingested NPs cleared from the organs completely within 30-day elimination period, except the liver and spleen. Liver contained about 31% of alpha- and 46% of gamma-Fe2O3, while spleen retained about 62% of alpha- and 35% of the gamma-polymorph. No significant disturbances were observed in hematological parameters, including hemoglobin, hematocrit, red blood cell and white blood cell counts (p > 0.05). Serum glucose (GLU) levels decreased in treatments exposed to 1.0 mg/L of gamma-Fe2O3 NPs at day 30 (p < 0.05). In contrast, GLU levels increased during the elimination period for 1.0 mg/L alpha-Fe2O3 NPs treatments (p < 0.05). Transient increases occurred in glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and lactate dehydrogenase (LDH). Serum Fe levels did not change during exposure (p > 0.05), but increased significantly within elimination period due to mobilization of ingested NPs from liver and spleen to blood. Though respiratory burst activity was not affected (p > 0.05), lysozyme activity (LA) was suppressed suggesting an immunosuppressive effects from both Fe2O3 NPs (p < 0.05). In contrast, myeloperoxidase (MPO) levels increased significantly in treatments exposed to alpha-Fe2O3 NPs (p < 0.05), and the effect from gamma-polymorph was marginal (p > 0.05). The results indicate that morphological differences of Fe2O3 NPs could induce differential uptake, assimilation and immunotoxic effects on O. niloticus under chronic exposure. (C) 2016 Elsevier B.V. All rights reserved.Öğe Effects of subchronic exposure to zinc nanoparticles on tissue accumulation, serum biochemistry, and histopathological changes in tilapia (Oreochromis niloticus)(Wiley, 2017) Kaya, Hasan; Duysak, Muge; Akbulut, Mehmet; Yılmaz, Sevdan; Guerkan, Mert; Arslan, Zikri; Demir, VeyselZinc nanoparticles (ZnNPs) are among the least investigated NPs and thus their toxicological effects are not known. In this study, tilapia (Oreochromis niloticus) were exposed to 1 and 10 mg/L suspensions of small size (SS, 40-60 nm) and large size (LS, 80-100 nm) ZnNPs for 14 days under semi-static conditions. Total Zn levels in the intestine, liver, kidney, gill, muscle tissue, and brain were measured. Blood serum glucose (GLU), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and lactate dehydrogenase (LDH) were examined to elucidate the physiological disturbances induced by ZnNPs. Organ pathologies were examined for the gills, liver, and kidney to identify injuries associated with exposure. Significant accumulation was observed in the order of intestine, liver, kidney, and gills. Zn levels exhibited time- and concentration-dependent increase in the organs. Accumulation in kidney was also dependent on particle size; NPs SS-ZnNPs were trapped more effectively than LS-ZnNPs. No significant accumulation occurred in the brain (p>0.05) while Zn levels in muscle tissue increased only marginally (p0.05). Significant disturbances were noted in serum GOT and LDH (p<0.05). The GPT levels fluctuated and were not statistically different from those of controls (p>0.05). Histopathological tubular deformations and mononuclear cell infiltrations were observed in kidney sections. In addition, an increase in melano-macrophage aggregation intensity was identified on the 7th day in treatments exposed to LS-ZnNPs. Mononuclear cell infiltrations were identified in liver sections for all treatments. Both ZnNPs caused basal hyperplasia in gill sections. Fusions appeared in the gills after the 7th day in fish treated with 10 mg/L suspensions of SS-ZnNPs. In addition, separations in the secondary lamella epithelia were observed. The results indicated that exposure to ZnNPs could lead to disturbances in blood biochemistry and cause histopathological injuries in the tissues of O. niloticus. (c) 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1213-1225, 2017.Öğe Effects of zinc oxide nanoparticles on bioaccumulation and oxidative stress in different organs of tilapia (Oreochromis niloticus)(Elsevier Science Bv, 2015) Kaya, Hasan; Aydin, Fatih; Gurkan, Mert; Yılmaz, Sevdan; Ates, Mehmet; Demir, Veysel; Arslan, ZikriNano-size zinc oxide particles (ZnO NPs) are used in diverse industrial and commercial fields. However, the information from existing studies is not sufficient in evaluating the potential toxic effects of ZnO NPs. In this study, tilapia fish (Oreochromis niloticus) were exposed to different concentrations of small and large ZnO NPs in vivo. Accumulation in various organs/tissues (liver, gill, intestine, kidney, brain and muscle) and possible oxidative stress mechanisms were investigated comparatively. Fish were exposed to 1 and 10 mg/L concentrations of small (10-30 nm) and large (100 nm) ZnO NPs semi-statically for 14 days. Both small and large ZnO NPs accumulated substantially in the tissues. Accumulation for the small ZnO NPs was significantly higher compared to larger NPs under same exposure regimes. Significant fluctuations were observed in antioxidant defense system biomarkers, including Superoxide dismutase (SOD), Catalase (CAT) and Glutathione (GSH) levels depending on particle size, exposure time and concentration. Lipid peroxidation measured with TBARS levels were higher in groups exposed to the suspensions of small ZnO NPs than that of large ZnO NPs and controls. These results imply that colloidal suspensions of small ZnO NPs induce elevated oxidative stress and toxic effects on tilapia compared to the larger NPs. (C) 2015 Elsevier B.V. All rights reserved.
