Induction of Micronucleus in Tadpoles of Odontophrynus americanus (Amphibia: Leptodactylidae) by the Pyrethroid Insecticide Cypermethrin

CABAGNA, M; LAJMANOVICH, R.C; PELTZER, P.M; ATTADEMO, M.; ALE, E

Toxicology Environmental and Chemistry

Taylor Francis

Año: 2006 vol. 88 p. 729 - 737

1029-0486

Cypermethrin (CY) is an active cyano pyrethroid effective against a wide range of pests encounteredin agriculture and forestry. Although CY is not mutagenic in in vitro assays for gene mutation, in vivoassays showed conflicting results. In vivo genotoxicity of the synthetic pyrethroid CY in erythrocytes ofOdontophrynus americanus tadpoles was examined. The frequency of micronuclei (MN) was recordedin blood smears obtained from tadpoles exposed in vivo to four different nominal concentrations5, 10, 20 or 40 mgL
1 of the compound and fixed at two sampling times 48 and 96 h. As a positivecontrol larvae were exposed to 40mgL
1 of cyclophosphamide (CP). Tadpoles exposed to all CYtreatments showed a significant increase in single small MN compared to the negative control groupafter 48 h and at 5 and 10 mgL
1 of CY at 96 h. Results obtained here demonstrated the genotoxiceffects of the commercial formulation CY in the anuran larvae analyzed. Thus, data suggest thatmeasurements of MN and other erythrocytes morphological aberrations performed in circulatingblood samples of O. americanus tadpoles is a method for detecting cytogenetic damage in other nativespecies.