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(W/MF146) Cytotoxic effects of Cd, Pb and Zn in shrews and BALB/c mouse cells in vitro. Chapman, Alétia1, Reinecke, Sophié1, Reinecke, Adriaan1, 1 ABSTRACT- Organisms exposed to heavy metals in the environment can absorb and accumulate these substances. Small mammals form an important link in the terrestrial food chain and by studying effects of toxicants on their cells, possible damage can be determined at an early stage. Shrews were studied as bioindicators of environmentals exposure and kept in the laboratory for cytotoxicity tests. BALB/c mice were also used due to the small numbers of shrews available. Splenocytes of shrews and laboratory mice as well as mice whole blood cells (WBC's) were studied in vitro, using primary cell cultures. The cells were exposed to different concentrations of CdCl2, PbCl2 and ZnCl2. After splenocytes and WBC's were incubated with the metals, the LDH (lactate dehydrogenase) activity was measured to determine membrane damage. The rate of [3H] Thymidine incorporation, an indication of DNA synthesis, into WBC's ,was measured to determine chemically induced damage to the nucleic acids, and the Trypan blue exclusion assay performed to assess cell viability. No LDH activity was observed but this might have been influenced by the presence of heparin in the medium. Results of the DNA synthesis assay were also negative but the Trypan blue tests indicated that exposure to Cd and Pb decreases cell viability with increasing exposure concentrations and that Zn increases this viability by stabilising cell membranes. Key words: bioindicator, heavy metals, membrane damage, cell viability |
