Metabolic responses of matrinxã, Brycon amazonicus (Spix & Agassiz, 1829), exposed to environmental nitrite |
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| Authors: | Ive Marchioni Avilez Lucia Helena de Aguiar Tiago Silvestre Hori Gilberto Moraes |
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| Institution: | 1. Department of Genetics and Evolution, Federal University of S?o Carlos, , S?o Carlos, SP, Brazil;2. Unicep – Centro Universitário Central Paulista, Centro Universitário Central Paulista, , S?o Carlos, SP, Brazil;3. Ocean Science Center, Memorial University of New Foundland, , St John's, Canada |
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| Abstract: | Nitrite is usually found in aquatic environments where nitrification process occurs. This ion can cause several injuries to aquatic species, particularly fish. Nitrite reacts with haemoglobin yielding the non‐functional methaemoglobin, which leads to many physiological consequences such as functional anaemia and supposed hypoxia. Metabolism of the freshwater teleost matrinxã, Brycon amazonicus, exposed to environmental 0.6 mg L?1 of nitrite N‐NO2? for 96 h was studied, and the fermentative/oxidative preference was gauged. Concentrations of glycogen, glucose, lactate, pyruvate and ammonia, plus the activities of lactate, glutamate and malate dehydrogenase were assayed. The exposure resulted in a metabolic profile that allowed inferring the continuity of oxidative metabolism. Catabolism of amino acids prevailed or was apparently exacerbated by inferred branchial injury and consequent impairment of nitrogen excretion. Moreover, the studied enzymes glutamate dehydrogenase, lactate dehydrogenase and malate dehydrogenase from brain and heart were little affected by nitrite. The expected fermentative metabolism due to the high methaemoglobin formation was not observed. |
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| Keywords: | methaemoglobin metabolism fish functional anaemia
LDH
GDH
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