Inconsistent results among reports on
cadmium genotoxicity revealed that certain confounding factors might significantly influence the outcomes of assessment. In Chinese hamster ovary (CHO-W8) cells,
chromosome aberration induced by six different
cadmium compounds was found positively associated with intracellular
cadmium concentration. A parallel association was also observed among different CHO strains treated with same
cadmium compound, the
cadmium acetate. Both the
cadmium-induced
chromosome aberration and
cadmium uptake were influenced by the presence of
fetal calf serum (FCS). The presence of 10% FCS during the 2h treatment period greatly retarded the cellular
cadmium uptake, and concurrently reduced the
chromosome aberration induction. Other factors such as specific
cadmium anion involved and the duration of
cadmium treatment period in the investigation also influenced the assessment results of
cadmium-induced
chromosome aberration. In the protocol with a 2h pulse treatment,
cadmium acetate,
chloride and
sulfate induced more
chromosome aberration than
cadmium nitrate,
carbonate and
oxide. When
cadmium was present in the culture of the entire treatment period for 18 h, the results went the opposite way.
Cadmium nitrate,
carbonate and
oxide induced significant
chromosome aberration, while other three
cadmium compounds gave negative results.
Cadmium compounds did not induce significant SCE at the same dose level that yielded significant
chromosome aberration induction, either in the protocol with the short pulse or long treatment period.