Resumo

IZAGUIRRE, María F. et al. Anuran experimental models to study pyrethroid effects. Cienc. docencia tecnol. [online]. 2006, n.32, pp.181-206. ISSN 1851-1716.

Aquatic ecosystems are increasingly exposed to numerous environmental contaminants, as agrochemicals. In recent years it has been observed that toxicity tests only span short time effects (mortality) but are not sufficient to evaluate the ecosystems risk. For that reason, long time estimations are very important as reference to estimate the incidence of those changes over the biodiversity and also on human health. In the present report we statistically analyzed, under laboratory conditions, the acute effect (mortality - survival) and subchronic doses (growth rate and development), as well as the alterations at histological and subcellular level produced by the cypermethrin pesticide. Bioassays on toxicity were carried out with embryos and tadpoles of critical stages of two regional anuran species: Physalaemus biligonigerus and Bufo arenarum. These species were chosen due to their biocides sensibility and ecological importance. Additionally, a morphological analysis of the target organs by optic and electron microscopy was carried on, to determine the development of adaptative mechanisms to the new adverse condition. Complementary studies of  in situ TUNEL and morphometry were made.

Palavras-chave : Cypermethrin; Anurans; Apoptosis; Histology; Ultrastructure.

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