Enhancement of UV and chromate mutagenesis by nickel ions in the Chinese hamster HGPRT Assay^†

Presented January 21, 1986 at the 2nd IAEAC Workshop on Carcinogenic and/or Mutagenic Metal Compounds in CH‐1884 Villars‐sur‐Ollon.

1. The HGPRT (Hypoxanthine‐Guanine‐Phospho‐Ribosyl‐Transferase) assay with Chinese Hamster V79 cells was used to measure the mutagenic effects of UV irradiation, potassium dichromate and nickel chloride. The agents were tested separately and in the combinations of UV plus nickel and dichromate plus nickel.

2. UV, Cr(VI) and Ni(II) were confirmed to be mutagenic in the V79 cell assay. The combination of UV(5J/m²) and Ni(II) (0.5 mM) caused a mutation rate 11.2 times above that corresponding to the sum of the individual mutation rates of these agents. The combined action of Cr(VI) (0.1 mM) and Ni(II) (0.5 mM) produced a mutation rate 2.8 fold above that corresponding to the sum of the individual rates of the separate agents.

3. The enhancing effect of nickel chloride on the mutagenicity of UV or Cr(VI) is interpreted by an interference of Ni(II) with the repair of DNA lesions.

Key words:

• Welding
• mutagenicity testing
• hamster V 79 cells
• synergistic effects
• DNA repair
• UV radiation
• chromate
• nickel chloride

Notes

Presented January 21, 1986 at the 2nd IAEAC Workshop on Carcinogenic and/or Mutagenic Metal Compounds in CH‐1884 Villars‐sur‐Ollon.