| Objective:To explore the effects of sodium arsenic on Cell survival percentage;DNA damage;production of Metallothionein(MT) and its isoform genes expression; Method:Extracts the healthy persons blood aseptically, separates the lymphocyte, uses 2, 5, 10, 15, 30, 60μmol/L sodium arsenites (2, 5, 10, 15, 30, 60μmol/L groups) to affect separately in the lymphocyte.Cell survival percentage was determined by MTT reduction assay. DNA damage was observed by single cell gel electrophoresis (SCGE or Comet Assay);Ag/hemoglobin saturation Atomic absorption spectrometry was used to determine MT protein levels. Reverse transcriptase-polymerase chain reaction ( RT-PCR) was used to determine the MT isoform-specific mRNA expression. Results: The cell survival percentage induced by 2.0 and 5.0μmol/L sodium arsenites was significantly higher than other groups (P<0.05); compared with control group: DNA damage in 30,60μmol/L group was different all times we observed, In 15μmol/L group DNA damage was only observed in 72h (P<0.05); and repeated measurement data AVOVA analysis showed the difference of production of MT are significant between groups,and MT levels got its peak on 48 hours. MT levels of low dose groups(2,5μmol/L)are much higher than other groups. There is no significant difference on MT-1 expression after exposed to sodium arsenites for 72h(P>0.05) ;MT-2 gene was up regulated after 2,5μmol/L sodium arsenites expose for 72h(P<0.05). production of MT is related with cell survive in 48h, 72h treated groups (P<0.05)and not displayed the same situation in 24h treated group(P>0.05),and the MT level is not related with cell DNA damage in all time groups (P>0.05). Conclusion:The sodium arsenite can induce the hormesis of cell survive and MT production ;up regulated of MT might be one mechanism of the protective function of low dose arsenic, low dose sodium arsenites can not induce DNA damage, we can not say that MT up regulate could protect lymphocyte avoid DNA damage.
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