PARENT SESSION
72 - Mutagenicity and Genotoxicity
8:00 AM to 6:30 PM, Wednesday, 15 May 2002
Exhibition Area

(72-02) Detection of genotoxicity by RAPDs on fish cells after acute and chronic exposure to B(a)P.

Castaño, Argelia¹, Becerril, Concepción^*,2, García, Patricia¹, Acevedo, Helda², ¹ INIA- centro de Investigación en Sanidad Animal. Valdeolmos, MADRID, SPAIN, SPAIN² Centro de Alimentación y Nutricion. I.S. Carlos III.Majadahonda, Madrid, SPAIN

ABSTRACT- Environmental genotoxins are often associated with the decline or disappearance of populations. Sensitive and specific tests are required to safely establish the security levels of chemicals prior to their use, or in the hazard assessment. In vitro tests, with controlled environment and genetic homogeneity, represent an advantageous technique in the first phases of genotoxicity studies. On the other hand, recent advances in molecular technology have opened a new chapter in the evaluation of a wide range of genetic effects and in species conservation efforts. The joint use of those newly developed molecular techniques and established cell lines from representative species, allow us to circumvent the problems associated to in vivo testing providing a new tool for the detection, by looking directly at the level of DNA sequence and the structure of populations. This works shows the genomic alterations after the exposure of a known pro-mutagen, benzo(a) pyrene, detected by Random Amplified Polymorphic DNA (RAPD) in vitro, on the fish derived cell line RTG-2 and in vivo, on peripheral blood cells of rainbow trout individuals. RTG-2 cells were exposed to 0.01,0.05, 0.1,0.5 ppm for 24, 48 and 72h and to 0.05 ppm for 15 and 30 days. The genetic alterations were established comparing exposed versus unexposed cell fingerprint: a) band intensity percentage (quantitative analyses) and b) absence/presence of new bands (qualitative analyses). The concentration and length of exposure are inversely related, confirming the results previously observed using the same cell line, chemical and exposure periods, but measuring the increase of micronuclei frequency. In vitro results were compared with those obtained on peripheral blood cells of rainbow trout individuals which have been treated with a single i.p injection of B(a)P. This study shows that the RAPD technique presents a high level of sensibility in the early detection of DNA damage produced by this relevant environmental chemical.

Key words: genotoxicity, RTG-2 cells, in vivo/in vitro, RAPD