ANALYSIS OF CYTOGENETIC DAMAGE INDUCED IN CHO CELLS BY THE PYRETHROIDINSECTICIDE FENVALERATE

A synthetic pyrethroid insecticide, fenvalerate, was tested for its ab ility to induce chromosome aberrations (CA) and sister chromatid excha nges (SCE) in CHO cells. Fenvalerate was assayed both in the presence and in the absence of a rat liver activation system (S9-mix). Our resu lts indicate that fenvalerate in the presence of S9-mix is able signif icantly to increase the frequency of CA, while in the SCE test this in crease occurred both in the presence and in the absence of S9-mix. In addition, fenvalerate affected the cell cycle, causing a decrease in t he mitotic index (MI) and in the proliferative rate index (PRI).