Effects of nitrite on antioxidants defenses of shrimp Pleoticus muelleri (Crustacea, Solenoceridae)

ESPINO, M.L.; VELURTAS, S.M.; DIAZ, A.C.

BIOCELL

INST HISTOL EMBRIOL-CONICET

Lugar: Mendoza; Año: 2013 vol. 37 p. 86 - 86

0327-9545

The shrimp Pleoticus muelleri is a commercially important species in Argentina and presents a great potential to aquaculture activity. Therefore, studies on the effects of the nitrogenous compounds present in the water are necessary, since it can affect the overall physiology and lead to increased mortality of organisms. An imbalance in the generation of free radicals is considered a physiological stress factor, so the measurement of total antioxidant capacity (AT) can be used to estimate the antioxidant defenses effects in these animals. The objectives of this study were to determine the median lethal concentration (LC50) to nitrite and to characterize their effects on total antioxidant defenses in the shrimp. Short-term LC50 toxicity tests were carried out at ten concentrations from 0 to 1500mg/l of nitrite. Free radical scavenging properties of hepatopancreas extracts of P. muelleri were evaluated by electron paramagnetic spin resonance spectrometry methods against the stable 1,1-diphenyl-2-picrylhydrazyl radical. The LC50 determined at 96hs was of 170,56mg/l. AT capacity was measured in individuals exposed to 100, 200, 400 and 500mg/l of nitrite. All treatments tested showed radical scavenging ability, but the percentage of decay with time was greater in shrimp exposed to concentrations of nitrite close to the LC50, showing higher antioxidant activity. However, in all cases signifi cant differences respect of control were determined. From the results it can be concluded that of measurement of AT can be proposed as a biomarker of pollution by nitrites.