Nitrite Toxicity to Danio rerio: Effects of Subchronic Exposure on Fish Growth

Guo

et al. 2018

Toxins

Hazardous contaminants, such as nitrite and microcystin-leucine arginine (MC-LR), are released into water bodies during cyanobacterial blooms and may adversely influence the normal physiological function of hydrobiontes. The combined effects of nitrite and MC-LR on the antioxidant defense and innate immunity were evaluated through an orthogonal experimental design (nitrite: 0, 29, 290 μM; MC-LR: 0, 3, 30 nM). Remarkable increases in malondialdehyde (MDA) levels have suggested that nitrite and/or MC-LR exposures induce oxidative stress in fish spleen, which were indirectly confirmed by significant downregulations of total antioxidant capacity (T-AOC), glutathione (GSH) contents, as well as transcriptional levels of antioxidant enzyme genes cat1, sod1 and gpx1a. Simultaneously, nitrite and MC-LR significantly decreased serum complement C3 levels as well as the transcriptional levels of splenic c3b, lyz, il1β, ifnγ and tnfα, and indicated that they could jointly impact the innate immunity of fish. The severity and extent of splenic lesions were aggravated by increased concentration of nitrite or MC-LR and became more serious in combined groups. The damages of mitochondria and pseudopodia in splenic macrophages suggest that oxidative stress exerted by nitrite and MC-LR aimed at the membrane structure of immune cells and ultimately disrupted immune function. Our results clearly demonstrate that nitrite and MC-LR exert synergistic suppressive effects on fish innate immunity via interfering antioxidant responses, and their joint toxicity should not be underestimated in eutrophic lakes.

Section: Methodsmentioning

confidence: 99%

Nitrite Enhances MC-LR-Induced Changes on Splenic Oxidation Resistance and Innate Immunity in Male Zebrafish

Guo

et al. 2018

Toxins

“…Nitrites are considered to be toxic to fish after acute (Pištěková et al 2005;Weirich and Riche 2006;Park et al 2007;Rodrigues et al 2007;Costa et al 2008;Ozcan et al 2010) as well as chronic exposure (Siikavuopio and Saether 2006;Kroupová et al 2008;Voslářová et al 2008;Kroupová et al 2010). The toxicity of nitrites for fish differs in dependence of many internal and external factors such as water quality, fish species, their size and individual sensitivity (Lewis and Morris 1986;Jensen 2003;Voslářová et al 2006).…”

mentioning

confidence: 99%

Nitrite toxicity assessment in Danio rerio and Poecilia reticulata

et al. 2011

Nitrite is a natural component of the nitrogen cycle in the environment. Although it usually occurs in low concentrations, elevated concentrations caused by effluents or affected nitrification process can lead to serious health deterioration of fish. Two aquarium fish zebrafish (Danio rerio) and guppy (Poecilia reticulata) are recommended to use as model organisms in toxicity tests. However, their sensitivity to nitrite can differ. The aim of this study was to define acute toxicity of nitrite by the semistatic method according to OECD No. 203 (Fish, Acute toxicity test). The series of 4 acute toxicity tests was performed, with 10 fish of both species used for each concentration and for the control. The 96hLC50 NO 2 -value for D. rerio and P. reticulata was 242.55 ± 15.79 mg·l -1 and 30.2 ± 8.74 mg·l -1 , respectively. We have proved significant difference (p < 0.05) in sensitivity between D. rerio and P. reticulata. The results showed different sensitivities to nitrites in tested fish species, which could be related to species-specific branchial chloride uptake mechanism. This is the first study on this fish species. Acute toxicity, NO 2 -

“…Generally, salmonid fish are the most sensitive freshwater fish species to aqueous aluminium (Howells et al 1990). The aquarium fish Danio rerio, which was chosen for the toxicity tests performed during our study, is often used for the assessment of the toxic effects of chemicals (Jurčíková et al 2007;Voslářová et al 2008;Mikula et al 2009). …”

mentioning

confidence: 99%

Acute Toxicity of the Preparation PAX-18 for Juvenile and Embryonic Stages of Zebrafish (Danio rerio)

et al. 2010

The preparation PAX-18 is a coagulation agent, which is used in water and wastewater treatment facilities and for the treatment of natural waters. The active compound is polyaluminium chloride (9% of Al). The application to the water environment could present a potential risk to different developmental stages of fish. The aim of this study was to assess and compare the toxicity of the preparation PAX-18 for embryonic and juvenile developmental stages of zebrafish (Danio rerio). The acute toxicity tests with juvenile fish aged 2-3 months were conducted according to the method OECD No. 203 in 5 series. For embryo toxicity test the method OECD No. 212 was used in 5 series. The semistatic methods were selected. The results of toxicity tests (the number of dead individuals at particular test concentrations) were subjected to probit analysis using the EKO-TOX 5.2 programme to determine LC50 values of PAX. The LC50 mean value of PAX for juvenile D. rerio was 749.7 ± 30.6 mg·l -1 (67.5 ± 2.8 mg·l -1 of Al) and 731.5 ± 94.1 mg·l -1 (65.8 ± 8.5 mg·l -1 of Al) for embryonic stages of D. rerio. The sensitivity of juvenile and embryonic stages to PAX were comparable (p > 0.01). The acute toxicity values of PAX-18 found in tests on D. rerio were 6-13 × higher than the concentration which is usually applied to waters (5-10 mg·l -1 of Al). Therefore, the acute toxicity effect on fish can be considered minimal. Polyaluminium chloride, zebrafish, danio, developmental stagesThe preparation PAX-18 is used as one of the possible methods in the restoration of eutrophic lakes. High loads of nutrients, mainly phosphorus, that enter surface waters, cause the eutrophication and intensive development of the phytoplankton with a negative effect on the water quality and species diversity (Holz and Hoagland 1999;Klouček and Vaverová 2005). The active compound of the preparation PAX-18 is polyaluminium chloride (9% of Al). Polyaluminium chloride is one of the most effective coagulant agents in water and wastewater treatment facilities and for the treatment of natural waters. It is used as an eliminator of colloids and suspended particles, organic matter, metal ions and phosphates (Pitter 2009; Zouboulis and Tzoupanos 2010).Aluminium treatment was found to be effective in lowering phosphorus concentration in water. Aluminium binds phosphorus and forms complexes that permanently attach this element to the bottom sediments. Furthermore, during the sedimentation of these complexes, floccules remove plankton from the water column and the water transparency improves (Holz and Hoagland 1999;Klouček and Vaverová 2005). Direct application of PAX-18 into the water (usually at doses of 5-10 mg of Al per one litre) or to the sediments (in tens of grams per 1 m 2 of surface of the bottom sediments) is possible (Pitter 2009). The application of PAX-18 to the natural waters could present a potential danger to fish and other water non target organisms due to the presence and accumulation of aluminium.Aluminium is a ubiquitous element in natural water...