In vitro toxicology of heavy metals using mammalian cells: an overview of collaborative research data.

The uptake and distribution of selected heavy metals were followed and related to cytotoxicity using various parameters of proliferation and viability of cultured cells. The effects of short-term lead exposure on DNA synthesis were reversible, indicating that lead does not significantly influence genetic cellular function. In contrast, nickel effects persisted, indicating that DNA is one of the main nickel targets.

Cell survival after the combined action of manganese (MnCl2) and X-rays in synchronized Chinese hamster cells.

The interactions between the effects of manganese chloride and X-rays were studied in synchronized populations of V79 Chinese hamster fibroblasts. The cells were selected by shaking off asynchronous cultures for detachment of mitotic cells which were plated in petri dishes and exposed to various treatments. Irradiation was carried out with a Philips RT-100 X-ray unit.

Cyclic nucleotides affect growth and differentiation of cultured rat embryonic shields.

The modified organ culture of rat embryonic shields provides favorable conditions during 2 weeks for the differentiation of main tissue types. Since the terminal differentiation in explants is inferior to that obtained in the homografts of the same shields under the kidney capsule, we tried to improve the culture medium by adding some known regulatory molecules: db-cAMP, db-cGMP, ATP, AMP, and butyric acid. These agents were added to the liquid medium in the concentration of 1 mM.

Toxicity of nickel for mammalian cells in culture.

The effects of nickel chloride were studied in two human cell lines, HeLa and diploid embryonic fibroblasts, as well as in V79 Chinese hamster cells and in L-A mouse fibroblasts. NiCl2 produces a dose-dependent depression of proliferation and mitotic rate. Effects on viability are accompanied by an increasing release of the intracellular enzyme lactic dehydrogenase.

The rate of DNA synthesis in HeLa cells during combined long-term and acute exposures to lead.

Asynchronous populations of HeLa cells growing as monolayers were incubated in a nutritive medium supplemented with a low concentration of 10(-5) M lead chloride for several months. At various time intervals the [3H]thymidine uptake was measured in the DNA of the cells by a scintillation counting technique. During the first 2 weeks of incubation, the rate of DNA synthesis was slightly reduced.

Cytotoxicity of manganese for mammalian cells in vitro--comparisons with lead, mercury and cadmium.

The effects of manganese chloride were studied in two human cell lines HeLa and human embryonic diploid fibroblasts in V79 Chinese hamster lung cells, and L-A mouse fibroblasts. Manganese produces a dose-dependent depression of proliferation along with a decrease of the mitotic rate. Effects on viability are accompanied by increased release of the intracellular enzyme lactic dehydrogenase.

[Lead and cadmium toxicity in established mammalian cell lines].

Lead and cadmium toxicity was evaluated in three mammalian cell lines (tumour : HeLa, transformed : XC and normal : NRK) by means of the modifications of the 3H-TdR incorporation rate in the nucleus of the treated cells. The three cell lines showed different degrees of sensitivity. Sensitivity depended on the line, metal, its concentration and duration of incubation.

Reversible inhibition of DNA, RNA and protein synthesis in human cells by lead chloride.

An acute intoxication by lead chloride (conc. 2.5 - 10(-4)M) produces a temporary reduction of macromolecular syntheses in HeLa cells growing asynchronously.