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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

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

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Leite, Patricia Zazeri [1] ; Stefani Margarido, Tatiana Cristina [1] ; de Lima, Daina [1] ; Rossa-Feres, Denise de Cerqueira [2] ; de Almeida, Eduardo Alves [1]
Total Authors: 5
[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
Total Affiliations: 2
Document type: Journal article
Source: Environmental Science and Pollution Research; v. 17, n. 8, p. 1411-1421, SEP 2010.
Web of Science Citations: 15

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)

FAPESP's process: 04/04820-3 - Fauna and flora from forest fragments in the northwest region of São Paulo State: the basis to biodiversity conservational studies
Grantee:Orlando Necchi Junior
Support type: BIOTA-FAPESP Program - Thematic Grants