In vivo and in vitro inhibition of cholinesterase activity in Colossoma macropomum (tambaqui) fingerlings by the herbicide trifluralin
DOI:
https://doi.org/10.5132/eec.2015.01.04Palavras-chave:
Acetylcholinesterase, Biomarker, Brain, Muscle, Freshwater fish, HerbicidesResumo
The Amazonian fish Colossoma macropomum (tambaqui) is farmed intensively in rice paddies around the São Francisco River delta in northeast Brazil, where the herbicide trifluralin is regularly used. The aims of this study were to evaluate the inhibitory effects of trifluralin on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) of brain and muscle from C. macropomum in order to assess the value of this species as a sentinel for herbicide contamination. Trifluralin was highly toxic to fingerlings in vivo (96 h-LC50 = 0.42 mg L-1). Cholinesterase activity in cell-free extracts of brain was associated with two isoforms, AChE and BChE, although the former predominated. The specific activity of brain AChE was reduced significantly (p < 0.05) following 96.h exposure of fingerlings to trifluralin at 0.5 and 0.75 mg L-1, but increased by 30% after exposure to 1.0 mg L-1 of herbicide. Muscle AChE was not affected by exposure to trifluralin. Km and Vmax values of brain AChE were 0.043 ±.0.015 mmol L-1 and 0.301.±.0.014 mmol min-1 mg-1protein, respectively. Brain AChE was moderately sensitive to trifluralin (IC50 = 0.78 mg L-1), but was very sensitive to the anticholinesterase agent eserine (IC50 = 0.043 mg L-1). AChE inhibition in C. macropomum may be employed as a biomarker for biomonitoring trifluralin contamination in water bodies.
Downloads
Publicado
Como Citar
Edição
Seção
Licença
Copyright (c) 2015 Ecotoxicology and Environmental Contamination
Este trabalho está licenciado sob uma licença Creative Commons Attribution 4.0 International License.
Copyright © 2006 ECOTOX-Brasil
Copyright notice: It is a condition for publication that manuscripts submitted to this journal have not yet been published and will not be simultaneously submitted or published elsewhere. By submitting a manuscript, the authors agree that copyright for their article is transferred to the Sociedade Brasileira de Ecotoxicologia (ECOTOX-Brasil) if and when the article is accepted for publication. The copyright covers the exclusive rights to reproduce and distribute articles, including reprints, photographic reproductions or any other reproduction of a similar nature, including translations. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without permission of the publisher.
Notice: While every effort is made by the EEC, editors and editorial board to see that no inaccurate or misleading data, opinions or statements appear in this journal, they wish to make it clear that the contents of the articles and advertisements published herein are the sole responsibility of the contributors or advertisers concerned. Accordingly, the EEC, the editorial board and editors and their respective employees, officers and agents accept no responsibility or liability whatsoever for the consequences of any inaccurate or misleading data, opinion or statement.
