Further evidence for the aneuploidogenic properties of chelating agents: induction of micronuclei in mouse male germ cells by EDTA.

A micronucleus assay based on cytogenetic analysis of early spermatids (Tates et al.; Mutation Research 121:131-138, 1983) was applied to determine if the chelating agent ethylenedinitrilotetraacetic acid (EDTA) may induce aneuploidy in mouse meiotic cells. Previous results indicated aneuploidogenic activity of EDTA in Drosophila female germ cells (induction of chromosome loss; Zordan et al.: Environ Mol Mutagen 15:205-213, 1990). In the same study, a standard aneuploidy test based on chromosome counting in mouse secondary spermatocytes failed however to show aneuploidogenic properties of EDTA in mouse somatic and germ cells. In the present study the effects of two clastogens, adriamycin (ADM) and mitomycin C (MMC), and of the aneuploidogenic agent chloral hydrate (CH) were also evaluated. All compounds were tested at a single dose level and at two time intervals corresponding to the treatment of diakinesis/metaphase I/metaphase II spermatocytes. The clastogenic potential of the compounds under study was also evaluated, by chromosomal aberration analysis in mouse spermatogonia, in an independent set of experiments. The results obtained indicate that ADM, CH and EDTA are able to induce micronuclei at meiosis. On the contrary, only ADM and MMC induced chromosomal aberrations in mouse spermatogonia. Therefore, the most probable origin of micronuclei produced by CH and EDTA is whole chromosome lagging. These results provide further evidence for the aneuploidogenic properties of these chelating agents.