Environmental genotoxicity evaluation using cytogenetic end points in wildrodents

We analyzed cytogenetic end points in three populations of two species of w ild rodents-Akodon montensis and Oryzomys nigripes-living in an industrial, an agricultural, and a preservation area at the Itajai Valley, state of Sa nta Catarina, Brazil. Our purpose was to evaluate the performance of the fo llowing end points in the establishment of a genotoxic profile of each area : the polychromatic/normochromatic cell ratio; the mitotic index; the frequ ency of micronucleated cells both in the bone marrow and peripheral blood; and the frequency of cells with chromosome aberrations in the bone marrow. Preparations were obtained using conventional cytogenetic techniques. The r esults showed a) the role of the end points used as biomarkers in the early detection of genotoxic agents and in the identification of species and pop ulations at higher risk; b) the difference in sensitivity of the species se lected as bioindicators in relation to the cytogenetic end points analyzed; c) the need to use at least two sympatric species to detect the presence o f genotoxins in each locality; and d) the need to use several end points wh en trying to establish a genotoxic profile of an area.