• Journal of fish pathology
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• v.20 no.3
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• pp.291-297
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• 2007

The effect of aspirin on the recovery of nitrite-induced methemoglobinemia in cultured eels (Anguilla japonica) was studied. Methemoglobinemia was induced by exposing eels to nitrite (120 ㎎ NO2-N/ℓ) for 24 hr. The nitrite exposed eels were bathed in 20 ppm aspirin solution (Aspirin), 0.8 % NaCl solution (NaCl), 20 ppm aspirin plus 0.8% NaCl solution (NaCl + Aspirin) and 50% nitrite free water(control) for 24 hr to recover from nitrite toxicity. Peripheral blood was taken from the arterious bulb from all groups to analyse hematocrit value, hemoglobin concentration, and nitrite concentration of the blood. Histopathological features of gill were also observed. Aspirin and control groups were more effective than NaCl and NaCl + Aspirin groups in recovery of hematocrit value and hemoglobin concentration, methemoglobin rate and nitrite concentration. The histopathological features on the gill of aspirin group were similar to those of normal eels, but other groups showed focal hyperemia in the lamellar carpillaries, epithelial hyperplasia. These results suggested that aspirin was very effective to recover from methemoglobinemia in nitrite-induced cultured eels.

• Journal of fish pathology
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• v.26 no.1
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• pp.1-9
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• 2013

The acute toxicity and sublethal effects of nitrite on the dark-banded rockfish, Sebastes inermis (mean body weight: $83.3{\pm}7.2$ g), were studied under static conditions for a period of 96 h. The acute toxicity of nitrite was at the 50% lethal concentration ($LC_{50}$) of 700 mg/L. The sublethal effects on selected hematological parameters of the dark-banded rockfish, such as its osmolality, hematocrit, cortisol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST), were measured after 0, 6, 12, 24, 48, 72, and 96 h of exposure to 0, 50, 100, 200, 400, or 700 mg/L nitrite. Sublethal nitrite caused a progressive reduction in the hematocrit of the fish, depending on the nitrite concentration and the exposure period. Exposure to 100-700 mg/L nitrite for 96 h caused a reduction in the hematocrit and an increase in cortisol, ALT, and AST compared with the control levels. Abnormal ultrastructural changes in the gills and liver tissues were observed in fish exposed to 700 mg/L nitrite for up to 96 h compared with the control tissues. Ultrastructural changes included atrophic gill mitochondria and hepatocytes that developed smooth endoplasmic reticulum and atrophic mitochondria. Although no rockfish mortality occurred at 500 mg/L nitrite, all the hematological parameters examined responded adversely to a nitrite dose of 200 mg/L for 96 h. These results show that although the acute toxic concentration of nitrite for the dark-banded rockfish is > 700 mg/L, sublethal concentrations of nitrite also negatively affect its hematological parameters.

• Journal of fish pathology
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• v.17 no.3
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• pp.199-205
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• 2004

Effects of nitrite, ammonia and hydrogen sulfide on survival of the early developmental stages of Fenneropenaeus chinensis were determined under continuous flow-through system. The 96hr-$LC_{50}$ values of mysis stage were 18.4 mg/L, 0.69 mg/L and 13.5 $\mu{g}/L$ for nitrite, ammonia and hydrogen sulfide, respectively; 28.3 mg/L, 1.23 mg/L and 20.7 $\mu{g}/L$ for post larva stage and 39.8 mg/L, 1.73 mg/L and 28.5 $\mu{g}/L$ for juvenile stage, respectively. The Fenneropenaeus chinensis sensitivity for the three pollutants was in the order of hydrogen sulfide>ammonia>nitrite. The mysis/post larva, mysis/juvenile and post larva/juvenile ratios of nitrite, ammonia and hydrogen sulfide toxicity were >1.5, >2.0 and <1.5 times, respectively, and mysis were found to be more sensitive to pollutants than juvenile in all cases.

• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.211-219
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• 1996

The inhibitory effect of cyclosporin A (CsA) on nitric oxide production is not related to the immunosuppressive action of the drug, but to the renal toxicity and arterial hyper-tension. In this study the experimental interventions to reverse the inhibition of nitric oxide production by cyclosporin A in rat aortic smooth muscle cells were examined. CsA inhibited the accumulation of nitrite, the stable end product of nitric oxide, in culture media in a concentration $(0.1{\sim}100{\mu}g/ml)-dependent$ manner. The inhibitory effect of CsA on nitrite accumulation were not antagonized by arginine (10 mM), a substrate of nitric oxide synthase, nor by calcium ionophore A23187 $(7{\mu}M)$. Forskolin, an activator of adenylate cyclase, which enhanced iNOS induction at transcriptional level, completely reversed the inhibitory action of CsA on nitrite accumulation. However, PMA (2 nM) and PDB (50 nM), PKC activators, increased the inhibitory action of CsA on nitrite accumulalion. From these results, it is suggested that cyclic AMP-elevating agents may be candidates of therapeutic agents in prevention and treatment of renal toxicity and arterial hypertension induced by CsA. Among conventional antihypertensive drugs, calcium channel blockers and ${\alpha}-blockers$ are preferred to ${\beta}-blockers$.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.494-498
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• 2016

Cold plasma has been developed to reduce microbial contamination and to improve safety of food and medical products. In addition, the technology can be used in the manufacture of sausages without addition of nitrite. To be applied in food industry commercially, the new technology should be safe and efficient. However, toxicological test of plasma-treated food is limited. Therefore, the purpose of this study was to determine the mutagenicity and immune toxicity of the meat products cured with plasma-treated water (PTW) as a nitrite source. Emulsion sausages were prepared with no nitrite (control), sodium nitrite (SCS), and PTW (SCP). For a mutagenicity test, the Ames test was performed with the sausage samples. For immune toxicity test, 8-wk-old female Balb/c mice were given free access to the sausages in order to evaluate the tumor necrosis factor (TNF)-α level. As a result, no mutagenicity was detected in the sausages by the Ames test. The serum TNF-α values were less than 10 pg/mL in mice after feeding control and treated samples for 32 d, indicating that no inflammatory response was occurred by feeding the sausages made by PTW. Therefore, the present study opens the possibility of using plasma-treated water as a nitrite source without any toxicity.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.367-372
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• 2004

Nitrite, a curing agent of meat products, is precursors of carcinogenic N-nitrosamines during processing of meat products or under human stomach conditions as well as having its own toxicity. Some researches have been conducted to evaluate the effects of ionizing radiation on the reduction of residual nitrite and N-nitrosamines in an aqueous model system and cured meat products with different packaging methods during storage. These results showed that the gamma irradiation was effective in reducing the residual nitrite and N-nitrosamines in an aqueous model system as well as meat products. Especially, irradiation combined with vacuum or modified atmosphere packaging was more effective in nitrite and N-nitrosamines reduction than aerobic packaging during storage. The objective of this review is to introduce the irradiation technology for the application of reducing the residual nitrite and N-nitrosamine contents in meat products.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.314-320
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• 2014

BACKGROUND: Run off from agricultural sites contaminates water bodies with nitrogen which is toxic and causes eutrophication when excessively accumulated. Hence, the interest in monitoring nitrogen toxicity in aquatic environment has been continuously increasing. METHODS AND RESULTS: To detect a real time toxicity of various nitrogen compounds, we applied biomonitoring method (biosensor) based on sulfur-oxidizing bacteria (SOB). The toxicity biomonitoring test was conducted in semi-continuous mode in a reactor filled with sulfur particles (2~4 mm diameter) under aerobic condition. Relative toxicity was simply determined by measuring the change in electrical conductivity (EC). Various nitrogenous compounds at different concentrations were evaluated as a potential toxic substance. Nitrite was found to be very toxic to SOB with a 90% inhibition even when the concentration as low as 3 mg/L. However, nitrate and ammonia have any inhibitory effect on SOB's activity. CONCLUSION: The biosensor based on SOB responded sensitively to nitrite even at substantially low concentrations. Therefore, it can be used as a reliable biological alarm system for rapid detection of contaminants due to its simplicity and sensitive nature.

• Journal of Plant Biotechnology
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• v.6 no.4
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• pp.259-264
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• 2004

The present study describes the ameliorating effect of $Ca^{++}\;on\;Cd^{++}$ toxicity on the germination, early growth of mungbean seedlings, nitrogen assimilation enzyme. s-nitrate reductase (NR), nitrite reductase (NIR), anti-oxidant enzymes (POD, CAT and SOD) and on the accumulation of hydrogen peroxide and sulphydryls. $Cd^{++}$ inhibited seed germination and root and shoot length of seedlings. While NR activity was down- regulated, the activities of NIR, POD and SOD were up- regulated with $Cd^{++}$ treatment. $Cd^{++}$ treatment also increased the accumulation of sulphydryls and peroxides, which is reflective of increased thiol rich proteins and oxidative stress. $Ca^{++}$ reversed the toxic effects of $Cd^{++}$ on germination and on early growth of seedlings as well as on the enzyme activities, which were in turn differentially inhibited with a combined treatment with calcium specific chelator EGTA. The results indicate that the external application of $Ca^{++}$ may increase the tolerance capacity of plants to environmental pollutants by both up and down regulating metabolic activities. Abbreviations: $Cd^{++}= cadmium,\;Ca^{++} = calcium$, NR= nitrate reductase, NIR=nitrite reductase, POD = peroxidse, SOD= superoxide dismutase, CAT= catalase, EGTA= ethylene glycol-bis( $\beta-aminoethyl ether$)-N,N,N,N-tetraacetic acid.

• Journal of fish pathology
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• v.34 no.2
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• pp.201-212
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• 2021

Olive flounder (Paralichthys olivaceus) (Weight 110.9±17.1 g, length 22.3±1.2 cm) were exposed to waterborne nitrite at 0, 30, 60, 120, 240, 480 and 960 mg NO₂^-/L according to water temperature at 20℃ and 25℃ for 96 hours. The lethal concentration 50 (LC₅₀) of olive flounder, P. olivaceus exposed to waterborne nitrite was 513.87 mg NO₂^-/L at 20℃ and 208.35 mg NO₂^-/L at 25℃, which means a significant difference in LC₅₀ by the water temperature. Hemoglobin and hematocrit were significantly decreased by waterborne nitrite exposure. The inorganic component, plasma calcium, was significantly decreased, and the organic components such as plasma glucose and cholesterol were significantly decreased showing a similar tendency with calcium. In enzymatic components, the AST and ALP were also significantly decreased by nitrite exposure. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of P. olivaceus, and the effect of exposure to nitrite had a significant effect on nitrite toxicity depending on the water temperature.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.90-95
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• 2009

This study investigates the oxidative degradation of N-nitrosodimethylamine (NDMA), a probable human carcinogen, by advanced oxidation process (i.e., UV process). The experiments were performed with various pH, initial concentration, UV intensity, and addition of $H_2O_2$ or $TiO_2$ on UV process. The results showed that the direct UV photolysis was the most effective treatment method. The lower pH, intial concentration and higher intensity of UV stimulated higher NDMA removal. However, addition of oxidant ($H_2O_2$, $TiO_2$) slows down photochemical treatment of NDMA since the oxidant can filter out the UV light and block it to reach the NDMA molecules. Dimethylamine (DMA) and nitrite were found to be a major byproduct from NDMA oxidation. To evaluate the chronic toxicity effects of UV-treated NDMA on the growth of microalgae, "Skeletonema costatum", was studied as long term experiments. Results demonstrated that after the 13 days exposure the chronic toxicity was decreased about 15% with application of UV process on NDMA degradation.