Evaluation of lactate dehydrogenase and malate dehydrogenase of Astyanax bimaculatus (lambari) from Una River basin as biomarker of enviromental impact

Abstract

The fish spend their whole life cycle in water and receive the influence of its physico-chemical and biological components over time. The activities of lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) of aquatic organisms can be altered by pollutants in the water. The aim of this study was to determine whether the activities of LDH and MDH in the gills and liver of Astyanax bimaculatus (lambari do rabo amarelo), can be used as biomarkers of environmental impact in the Una River (SP) basin. For these studies the lambaris were collected from three water bodies of this basin named p1 (Itaim River), p2 (stream located on the edge of city road Remédios) and p3 (lake in the city road Dr. José Luiz Cembranelli). The gills and liver were homogenized and next, this material was centrifuged and the supernatant was used for LDH and MDH activity assays by spectrophotometric method, which determined oxidation rate of NADH. The activities of hepatic LDH and MDH and gill MDH were not statistically different in the lambaris collected at the three sites. In the gill tissue, LDH activity of lambaris from p3 was lower than that from p1.This inhibition of LDH in lambaris from p3, as well as the water of inferior quality there, suggest the occurrence of pollutants in this water. It is concluded that LDH of lambari gills has potential for use as a biochemical marker of environmental impact at Una River.