Thyroid disruption in the lizard Podarcis bocagei exposed to a mixture of herbicides: a field study
| Autor: | Maria José Amaral, Miguel A. Carretero, Deborah M. Power, Reinier M. Mann, Alexandra Rêma, Amadeu M.V.M. Soares, Rita C. Bicho, Augusto Faustino |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Male
Health Toxicology and Mutagenesis Thyroid Gland 010501 environmental sciences Toxicology 01 natural sciences Testis Acetamides Testosterone Testes 2. Zero hunger 0303 health sciences Receptors Thyroid Hormone Tests Thyroid Vertebrate Lizards Agriculture General Medicine Environmental exposure Seminiferous Tubules Up-Regulation medicine.anatomical_structure Seminiferous tubule endocrine system medicine.medical_specialty Terrestrial ecotoxicology Zoology Reptile Management Monitoring Policy and Law Biology 03 medical and health sciences biology.animal Internal medicine parasitic diseases medicine Animals Ecotoxicology 030304 developmental biology 0105 earth and related environmental sciences Thyroid hormone receptor Thyroid gland Portugal Herbicides Lizard Field study Environmental Exposure Endocrinology sense organs EDC |
| Zdroj: | Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP |
| Popis: | Pesticide exposure has been related with thyroid disrupting effects in different vertebrate species. However, very little is known about the effects of these compounds in reptiles. In the Mediterranean area, lacertid lizards are the most abundant vertebrate group in agroecosystems, and have been identified as potential model species for reptile ecotoxicology. The aim of this study was to understand if the herbicides applied in corn fields have thyroid disruptive effects in the lizard Podarcis bocagei. Adult male lizards were captured in north-western Portugal in corn fields treated with herbicides (exposed sites), and in organic agricultural fields (reference sites). Thyroid and male gonad morphology and functionality, and testosterone levels were investigated through histological, immunohistochemical and biochemical techniques. Lizards from exposed locations displayed thyroid follicular lumens with more reabsorption vacuoles and significantly larger follicular area than those from reference fields. Furthermore, testes of lizards from exposed locations had significantly larger seminiferous tubule diameters, significantly higher number of spermatogenic layers and displayed an up-regulation of thyroid hormone receptors when compared with lizards from reference areas. These findings strongly suggest that the complex mixture of herbicides that lizards are exposed to in agricultural areas have thyroid disrupting effects which ultimately affect the male reproductive system. Alachlor, which has demonstrated thyroid effects in mammals, may be largely responsible for the observed effects. We appreciate the assistance of Ricardo Valente and CIBIO members. All lizards were collected under a permit issued by the Instituto da Conservação da Natureza e Biodiversidade. This research and the technical position of R.C. Bicho was supported by FEDER through COMPETE-Programa Operacional Factores de Competitividade and National funding through FCT-Fundação para a Ciência e Tecnologia, within the research project LAB-PET—Lacertid Lizards as Bioindicators of Pesticide Exposure and Toxicity in intensive market garden agriculture (FCT PTDC/AMB/64497/2006). M. J. Amaral benefited from a doctoral grant from FCT (SFRH/BD/31470/2006). published |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|