Oxidation of nitrite to nitrate in isolated erythrocytes: a possible mechanism for adaptation to environmental nitrite
| Autor: | C. Doblander, Reinhard Lackner |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
biology
chemistry.chemical_element Aquatic Science biology.organism_classification Oxygen Anoxic waters Methemoglobin chemistry.chemical_compound Red blood cell medicine.anatomical_structure Nitrate chemistry Biochemistry medicine Rainbow trout Food science Nitrite Ecology Evolution Behavior and Systematics Salmonidae |
| Zdroj: | Canadian Journal of Fisheries and Aquatic Sciences. 54:157-161 |
| ISSN: | 1205-7533 0706-652X |
| Popis: | Rainbow trout (Oncorhynchus mykiss) were exposed to nitrite (0.007 mmol NO2-· L-1) for 48 days. During the first 14 days, the methaemoglobin concentration in the blood as well as the NO2-and NO3-concentrations in the plasma increased whereas further days of exposure led to a decrease in the nitrite, nitrate, and methaemoglobin concentrations in the blood. Isolated erythrocytes from rainbow trout have the ability to detoxify nitrite by oxidation to nitrate, thus removing this compound from the blood. This process is dependent on oxygen loading of haemoglobin and on the nitrite concentration in the medium. In anoxic erythrocytes the oxidation of nitrite to nitrate is drastically reduced. Assuming Michaelis-Menten kinetics, the uptake for nitrite in our investigation was estimated between 1.06 and 2.21 µmol NO2-· h-1· kg fish-1. After 14 days of exposure approximately 20% of the total NO2-taken up will be detoxified by erythrocytes in fish. We hypothesize that rainbow trout have the capacity for adapting to nitrite exposure by increasing the rate of oxidation to nitrate. |
| Databáze: | OpenAIRE |
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