Table 4.
Total GSH, GSSG, ratio of GSSG/total GSH and MDA in the lung of mice at 14 days after exposure to zinc oxide nanoparticles by pharyngeal aspiration
| Amount of ZnO-NPs administered (μg) | Simple regression | Multiple regression | ||||||
|---|---|---|---|---|---|---|---|---|
| Genotype | 0 | 10 | 30 | Effect of ZnO-NPs | Interaction of ZnO-NPs and Nrf2 deletion | Effect of ZnO-NPs | Effect of Nrf2 deletion | |
|
Total glutathione (GSH + GSSG, nmol / g lung tissue) |
Wild type Nrf2−/− |
47.9 ± 6.5 42.9 ± 10.4 |
41.4 ± 7.3 44.9 ± 7.5 |
45.4 ± 7.8 51.5 ± 5.2 |
−0.041 (p = 0.71) 0.29 (p = 0.032) |
0.17 (p = 0.053) |
0.11 (p = 0.22) | 0.78 (p = 0.48) |
| Glutathione disulfide (GSSG, nmol / g lung tissue) |
Wild type Nrf2−/− |
5.8 ± 2.6 8.0 ± 2.2 |
5.1 ± 1.1 8.2 ± 2.0 |
6.2 ± 2.2 4.9 ± 2.0* |
0.020 (p = 0.52) − 0.11 (p = 0.0036) |
− 0.066 (p = 0.0057) | – | – |
| Ratio of GSSG/GSH (×10−1) |
Wild type Nrf2−/− |
1.48 ± 0.37 2.37 ± 0.67 |
1.45 ± 0.30 2.22 ± 4.41 |
1.62 ± 0.67 1.08 ± 0.54* |
0.00052(p = 0.47) −0.0045 (p < 0.0001) |
−0.0025 (p < 0.0001) | – | – |
|
MDA (nmol / mg protein) |
Wild type Nrf2−/− |
2.34 ± 0.37 1.42 ± 0.18 |
2.27 ± 0.27 1.38 ± 0.47 |
1.27 ± 0.19* 1.97 ± 0.67 |
−0.038 (p < 0.0001) 0.020 (p = 0.019) |
0.029 (p < 0.0001) |
– | – |
Mean ± SD. * p < 0.05compared to the corresponding genotype control by Dunnett’s multiple comparison following ANOVA. Simple regression analysis in each genotype and multiple regression analysis in a model with interaction was conducted. As the interaction was not significant for total glutathione, multiple regression in a model without interaction was finally conducted to estimate effect of ZnO-NPs and Nrf2 deletion