Role of mitochondrial calcium homeostasis in hyperoxia-induced injury to alveolar epithelial cells typeⅡ in rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of mitochondrial calcium homeostasis in hyperoxia-induced injury to alveolar epithelial cells typeⅡ(AECⅡ) in rats.Methods:Rat AECⅡcell lines (RLE-6TN) were randomly divided into 3 groups ( n=18 each) using a random number table method: nomoxia group (group C), hyperoxia group (group H), and hyperoxia plus ruthenium red group (group HR). The cell lines were cultured in a conventional incubator for 4 h in group C. The cell lines were incubated in an incubator with 90% O 2 for 4 h in group H. In group HR, ruthenium red 2 μmol/L was added first, and then the cell lines were incubated in an incubator with 90% O 2 for 4 h. After the treatment, the Ca 2+ concentrations in mitochondria were measured using the mitochondrial Ca 2+ specific fluorescent probe Rhod-2-AM, the ROS level was measured using the fluorescent probe DCFH-DA, and the cell morphology and mitochondrial ultrastructure were observed. Results:Compared with group C, the Ca 2+ concentrations in mitochondria and ROS level were significantly increased in H and HR groups ( P<0.05). Compared with group H, the Ca 2+ concentrations in mitochondria and ROS level were significantly decreased in group HR ( P<0.05). Compared group C, the cell volume was reduced, the morphology was shrunken round, the cell arrangement was loose, the mitochondrial double-layer membrane structure was broken, and the mitochondrial cristal fragments were observed in group H. Compared with group H, the cell morphology was significantly improved, and the slight damage to mitochondrial double-layer membrane structure was found, and the structure of mitochondrial cristae was normal in group HR. Conclusion:Mitochondrial calcium homeostasis is involved in the pathophysiological process of hyperoxia-induced injury to AECⅡ in rats.