Atividades de lactato desidrogenase e malato desidrogenase de Astyanax bimaculatus (lambari) da bacia hidrográfica do rio Una como biomarcadoras de impacto ambiental

Abstract

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 or Two Spots Astyanax in English), can be used as biomarkers of environmental impact in the Una River (SP) Basin. The lambaris for these studies were collected from three water bodies of this basin designated as p1 (Itaim River), p2 (stream by the road to the Municipality of Remédios) and p3 (lake on the road to the Municipality of Dr. José Luiz Cembranelli). The gills and liver were homogenized and this material was then centrifuged and the supernatant was used for LDH and MDH activity assays using the 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 inferior quality of water there, suggest the occurrence of pollutants in this water. It is concluded that the LDH of lambari gills has potential for use as a biochemical marker of environmental impact in the Una River.

Enzymes from kidney, gill and brain tissues of Astyanax bimaculatus (lambari) as biomarkers of environmental impact in the Una River basin

“…These results indicate that only SOD was sensible to environmental conditions present in P2. The physicochemical analysis of the water of sites P1, P2 and P3 at the time of fish capture has already been published, as well as the map with the location of these sites (Batista et al, 2014, Ribeiro et al, 2015. These data from the physicochemical analyses indicated that: (1) the less impacted site was P1, although its total phosphate level (0.3 mg L -1 ) was slightly elevated in relation to reference values (0.1 mg L -1 ); (2) the conductivity of the P2 aquatic environment (198.7 S cm -1 ) was 1.9 times higher than in P1, and 1.6 times higher than in P3, showing that P2 fish were exposed to high levels of electrolytes from an impacted environment (CETESB, 2009); (3) P3 presented the highest values of chemical oxygen demand (COD), indicating abundance of organic matter in the water.…”

“…Other suitable biomarkers are MDH from brain because the activity of brain MDH was elevated in fish from P3, as well as muscle MDH in fish from P2 (de Almeida et al, 2016). LDH from gills could also be a biomarker because the activity of gill LDH was lower in fish from P3, in comparison to those of P1 (Ribeiro et al, 2015).…”

“…The fish collection sites were: (1) Fazenda Piloto (P1) in the Itaim stream located on the property of Fazenda Piloto (an experimental farm) of the University of Taubaté (S 23º01' 38.3" W 45º30'31.6"); (2) Remédios (P2), a stream which flows to the Una River, located along the Remédios municipal road (S 23°03'26.4" W 45°30'23.5"), close to rice cultivation; (3) Ipiranga (P3), a lake near a pasture for cattle and close to the Dr. José Luiz Cembranelli municipal road (23º01'49.4" S and 45º30'16.7" W). The map of sampling sites was published in previous studies (Batista et al, 2014;Ribeiro et al, 2015). The specimen sampling was approved by MMA -SISBIO (authorization No.…”

“…The specimens of the fish Astyanax bimaculatus were collected at each of the three locations between December 2013 and March 2014. A size 20 nylon fishing net, as well as line and hook were used for collection as described by Batista et al (2014) and Ribeiro et al (2015). The fish were anesthetized with benzocaine 0.1%, dissected on an ice tray, and the tissues were stored at -86°C for further analysis.…”

“…The fish feeds on zooplankton, detritus, higher plants and sometimes fish scales, being an opportunistic feeder (Honorio and Martins, 2018). Levels of enzymatic activity of SOD and CAT of liver, and MDH and LDH of hepatic, muscular and branchial tissues of A. bimaculatus were previously investigated as candidate biomarkers of environmental changes in the Una River basin (Batista et al, 2014;Ribeiro et al, 2015;de Almeida et al, 2016). In this context, this work investigated the activity of SOD and CAT of renal and branchial tissues, MDH and LDH of renal and cerebral tissues, as well as brain AChE of A. bimaculatus.…”