纳米TiO2对四膜虫多药耐药基因和热激蛋白基因的影响

为探讨纳米TiO2在分子水平对生物的影响，运用RT—PCR半定量法研究不同浓度纳米TiO2对四膜虫多耐药（MDR1）和热激蛋白70（HSP70）基因表达活性的影响，结果表明，处理组中MDR1基因表达均高于对照组，且差异极显著（p〈0．01）；HSP70表现为高浓度抑制、低浓度诱导，表达量在低浓处理组中高于对照组，差异显著（p〈0．05）。随着纳米TiO2浓度的升高，处理组中HSP70表达量不断下降，当纳米TiO2浓度为100mg·L-1和500mg·L-1时，HSP70的表达量显著低于对照组中的表达量（p〈0．05），因此，纳米TiO2颗粒可以从分子水平影响梨形四膜虫，但确切的毒理还需要进一步的研究探索及验证。

Influences of Nano-TiO2 on Multidrug Resistance Gene and Heatshock Protein of Tetrahymena Pyriformis

To investigation the influence of nano-TiO2 on organism at the molecular level, the RT-PCR semi-quantitative method was employed to study the effects of Nano-TiO2 with different concentration on multidrug resistance （MDR1） gene expression and heatshock protein 70 （HSPT0） of tetrahymena pyriformis. The results showed that the MDR1 genes expression of Tetrahymena pyriformis with treation are significantly higher than those of control group （with difference about p〈0.01）. ,which indicated that HSPTO has high suppression ability at high concentrations, and induced ability at low concentrations. The HSP70 genes expression of Tetrahymena pyriformis in the low concentrations of nano-TiO2 are significantly higher than those in the control group （p〈0.05）. However, with nano-TiO2 concentration increasing, the HSPT0 genes expression of Tetrahymena pyriformis were declined, and the genes expression of Tetrahymenapyriformis at high concentrations（ 100mg·L-1 and 500mg·L-1 of Nano-TiO2）groups were significantly lower than those of control group, respectively （p〈0.05）. Through this experiment, it is known that Tetrahymena pyriformis would be affected by nano-TiO2 at the molecular level, and further research and verification are needed to clarify the toxicological mechanism.