Paraquat tolerance and alteration of internal gill structure of Scinax nasica tadpoles (Anura: Hylidae).
Arch Environ Contam Toxicol
; 34(4): 364-9, 1998 May.
Article
em En
| MEDLINE
| ID: mdl-9543506
Paraquat acute tolerance, and histological and ultrastructural response analysis of gills were evaluated in Scinax nasica tadpoles at stages 25-26. The treated tadpoles were able to survive with a mortality rate similar to the controls in media containing 6.48 to 10.80 mg PQ/L. At 18.00 mg PQ/L survival rate was about 85%; at 30.00 and 50.00 mg PQ/L an incremented mortality rate was detected. Their internal gills appear to have a critical role in adaptation to exposure to PQ. The LC-50 values found helped us conclude that increasing time of exposure to PQ produces a decrease of tadpole survival rate. With light microscopy, the apical ramification gill tufts exhibited a dose response increase of the total volume. At the ultrastructural level, an increase in the intercellular spaces and alteration in gill epithelium organization were the most notable changes. Furthermore, the capillaries showed enlarged endothelial cells, irregular nuclei, and numerous cytoplasmatic projections.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Paraquat
/
Brânquias
/
Herbicidas
Limite:
Animals
Idioma:
En
Revista:
Arch Environ Contam Toxicol
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Estados Unidos