Effects of heme oxygenase-1 preconditioning on oxidative damage in alveolar epithefial type II cells in rats

Objective To investigate the effects of heme oxygenase-1 （HO-1） preconditioning on oxidative damage in alveolar epithelial type Ⅱ （AE- Ⅱ） cells in rats. Methods The primarily cultured AE- Ⅱ cells isolated from male SD rats were randomly assigned to one of 6 groups （n = 8 each）： control group （group C）,H2O2 group and 4 different concentrations of HO-1 preconditioning group （group H1-4）. The cells were continuously incubated for 5 h in group C. H2O2 0.5 mmol/L was added and the cells were incubated for3 h in group H2O2.In group H1-4, HO-1 0.01, 0.10, 1.00 and 10.00 μmol/L were added and the cells were incubated for2 h, then H2O2 0.5 mmol/L was added and the cells were incubated for 3 h. After the end of incubation, the cell morphology was observed under inverted phase contrast microscope, the AE- Ⅱ cells were counted, and the cell viability was determincd. Results The most AE- Ⅱ cells were adherent and round, had homogeneous cytoplasm, and the cytoplasm contains granular materials in group C and H2-4, while the vacuoles appeared in AE- Ⅱ cells and the cell debris appearecd in the supernatant in group H2 O2 and H1 . Compared with group C, the cell count and cell viability were significantly decreased in group H2 O2 and H1 （P 〈 0.05）. Compared with group H2 O2 and H1, the cell count and cell viability were significantly increased in group H2-4 （P 〈 0.05）. There was no significant difference in the cell count and cell viability between group H2O2 and H1, and among group H2～4（P 〉 0.05） .Conclusion Preconditioning with 0.10-10.00 μmol/L HO-1 can reduce oxidative damage in rat AE- Ⅱ cells. Key words: Heme oxygenase-1; .Epithelial cells; Hydrogen peroxide