Esterase inhibition in tadpoles of Scinax fuscovarius (Anura, Hylidae) as a biomarker for exposure to organophosphate pesticides

Autor(es)

Leite, Patricia Zazeri ^[1] ; Stefani Margarido, Tatiana Cristina ^[1] ; de Lima, Daina ^[1] ; Rossa-Feres, Denise de Cerqueira ^[2] ; de Almeida, Eduardo Alves ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Dept Quim & Ciencias Ambientais, Inst Biociencias Letras & Ciencias Exatas, BR-15054000 Sao Jose Do Rio Preto - Brazil

^[2] Univ Estadual Paulista, Dept Bot & Zool, Inst Biociencias Letras & Ciencias Exatas, BR-15054000 Sao Jose Do Rio Preto - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 17, n. 8, p. 1411-1421, SEP 2010.
• Citações Web of Science: 15

Resumo

Organophosphate pesticides (OPs) are among the most used insecticides in agriculture, causing the inhibition of esterases like acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and carboxylesterase (CbE). Pesticides can reach the aquatic environment, posing risks to non-target organisms, including tadpoles. In this work, we characterized the activities of AChE, BChE and CbE in tadpoles of the snouted treefrog Scinax fuscovarius, and verified their in vitro sensibility to different inhibitors {[}phenylmethane sulfonyl fluoride (PMSF), tetra-isopropylpyrophosphamide (iso-OMPA) and the OP diazinon]. In vivo effects of diazinon and esterase recovery after 2-pyridine-aldoxime (2-PAM) treatment of the protein extract were also studied in tadpoles with distinct stages of development exposed to 1 and 3 mg/l for 2 and 7 days. Optimal conditions were established for AChE and CbE; BChE activity was negligible. PMSF affected esterase activities and is not recommended for homogenization buffers. Iso-OMPA treatment caused no changes in AChE and CbE activities, but diazinon inhibited these enzymes in a dose-responsive manner. In vivo, CbE activity was insensitive to diazinon in younger tadpoles, but inhibited after 2 days of exposure in more developed tadpoles. AChE activity was inhibited after 2 and 7 days of exposure, in a dose-responsive manner. Esterase reactivation by 2-PAM was obtained both in vitro and in vivo. (1) Tadpoles can be adequate sentinel organisms in biomonitoring studies of OP contamination; (2) AChE was more sensitive than CbE to diazinon; (3) tadpoles from earlier developmental stages seems to be less responsive to OPs; (4) AChE activity was sensitive to diazinon in both development stages, being a better OP biomarker. (AU)

• Processo FAPESP: 04/04820-3 - Fauna e flora de fragmentos florestais remanescentes no noroeste paulista: base para estudos de conservação da biodiversidade
• Beneficiário: Orlando Necchi Junior
• Linha de fomento: Auxílio à Pesquisa - Programa BIOTA - Temático
• Processo FAPESP: 06/03873-1 - Estudo de variações bioquímicas em tilápias, como biomarcadores de contaminação ambiental
• Beneficiário: Eduardo Alves de Almeida
• Linha de fomento: Auxílio à Pesquisa - Apoio a Jovens Pesquisadores